Ceramics, Volume 8, Issue 2 (June 2025) – 37 articles

The aim of this study is to evaluate the apical sealing ability of novel bioceramic-based (BCB) and widely used resin-based (RB) root canal sealers in combination with traditional or bioceramic-coated gutta-percha points. A total of 92 human single-root extracted teeth were endodontically treated and divided into three groups (A, B, and C) of 30 samples based on the endodontic sealer/type of gutta-percha points/obturation method used. One tooth sample was used for the negative and positive controls (each). Group A: BCB sealer BioRoot RCS (Septodont, Saint-Maur-des-Fossés, France)/bioceramic-impregnated gutta-percha TotalFill BC points (FKG Dentaire, La Chaux-de-Fonds, Switzerland)/cold hydraulic single-cone. Group B: BioRoot RCS (Septodont, France)/traditional Protaper Gold Gutta-Percha Points (Dentsply Sirona, Charlotte, NC, USA)/cold hydraulic single-cone. Group C: RB sealer AdSeal (Meta Biomed, Cheongju, Republic of Korea)/traditional Protaper Gold Gutta-Percha Points (Dentsply Sirona, USA)/warm vertical condensation. A dye penetration method was applied, and the length of apicocoronal penetration was measured using a surgical microscope. The data were statistically analyzed to evaluate differences at the 0.05 significance level. A significant difference was found between groups A and C, p = 0.0003, and groups B and C, p = 0.003. The data analysis proved that the BCB sealer using the cold hydraulic single-cone method ensured a substantially better seal than the RB sealer using the warm vertical condensation method. The choice of the type of gutta-percha points (bioceramic-coated or regular) appeared to be unimportant. No statistical significance was found between groups A and B, which indicates that using bioceramic-coated gutta-percha points does not bring any considerable benefit in view of a no-gap root canal obturation. Full article

MXenes, a class of two-dimensional materials with appealing properties such as electrical conductivity, mechanical strength, and chemical stability, is rapidly gaining attention for potential applications in various fields, including energy storage, water treatment, biomedicine, and electromagnetic shielding. One of the most exciting developments is their integration with 3D printing technologies, which allows for precise control over material structure and composition. This combination has significantly expanded the scope of MXenes, particularly in electrochemical storage systems like supercapacitors and batteries, where 3D-printed MXene-based materials have demonstrated superior performance. This review article provides a detailed analysis of the synthesis, properties, and applications of MXenes, with a particular focus on their role in additive manufacturing. While the synergy between MXenes and 3D printing offers numerous advantages, challenges such as large-scale production, material stability, and refining processing techniques remain significant hurdles; all these issues are discussed in the present work. Future research directions are also highlighted that aim to enhance scalability, reduce costs, and explore new composite formulations to optimize the performance of MXenes across various applications. Full article

This study aimed to evaluate prosthetic complications, implant survival rates, and marginal bone loss in implant-supported monolithic restorations compared to metal-ceramic restorations. The study was registered in PROSPERO (CRD420251022336) and conducted following the Cochrane Handbook for Systematic Reviews of Interventions and PRISMA guidelines. A systematic search was conducted in the electronic databases MEDLINE/PubMed, Web of Science, Scopus, Embase, and ProQuest for articles published up to December 2024. The inclusion criteria comprised studies evaluating only randomized clinical trials that evaluated implant-supported monolithic restorations directly compared to metal-ceramic restorations, considering any type of ceramic material and regardless of the fixation system (screw-retained or cemented), with a minimum follow-up of one year. A meta-analysis was performed using RevMan 5.4 software, and the risk of bias and certainty of evidence were assessed using the RoB 2.0 and GRADE tools, respectively. A total of six studies were included, all of which exclusively evaluated monolithic zirconia single crowns over follow-up periods ranging from 1 to 3 years. None of the included studies evaluated fixed partial dentures or restorative materials other than monolithic zirconia. In total, 267 patients (mean age range: 18–57 years) were analyzed, with a total of 174 implant-supported monolithic zirconia crowns and 165 metal-ceramic single crowns in the posterior region (premolars and molars). The meta-analysis revealed that implant-supported monolithic zirconia single crowns exhibited significantly fewer prosthetic complications compared to metal-ceramic single crowns (p < 0.0001; Risk Ratio [RR]: 0.26; Confidence Interval [CI]: 0.14–0.47). However, no statistically significant differences were observed between implant-supported monolithic zirconia and metal-ceramic single crowns regarding implant survival rates (p = 0.36; RR: 1.66; CI: 0.56–4.94) or marginal bone loss (p = 0.15; Mean Difference [MD]: −0.05; CI: −0.11–0.02). The risk of bias assessment indicated that four studies had a low risk of bias. However, the certainty of evidence was classified as low for prosthetic complications and implant survival rates and very low for marginal bone loss. Within the limitations of this review, it can be concluded that implant-supported monolithic zirconia single crowns can be considered a favorable treatment option as they show comparable implant survival and bone stability to metal-ceramic crowns, with a potential reduction in short-term prosthetic complications such as screw loosening and ceramic chipping. However, due to the limited number of studies included and low certainty of evidence, further long-term research is still needed to confirm their clinical performance over time. Full article

Diatomaceous biosilica has emerged as a functional material with unique properties, driving innovations in energy storage, therapeutic systems, and environmental catalysis. This article critically reviews recent advances in using natural biosilica in lithium-ion battery anodes, emphasizing how its hierarchical morphology and high porosity contribute to ion insertion and transport efficiency. Its surface chemistry enables controlled drug release and tissue regeneration in biomedical applications. Its synergy with metal catalysts enhances pollutant degradation in photocatalytic systems, especially via surface biofunctionalization. By linking these areas, this review highlights the potential of diatom biosilica as a viable and sustainable alternative to synthetic materials, promoting technological solutions aligned with circular economy and materials engineering. Full article

Nanopowders of hydroxyapatite (HA) and Fe-substituted hydroxyapatite (HAFe) were synthesized by wet precipitation on either MCM-41 (a synthetic, mesoporous aluminosilicate material) or an aluminum-containing MCM-41 (AlMCM) support. According to X-ray diffraction data, all of the synthesized materials are composite powders consisting of amorphous silicate and an HA phase with low crystallinity. The presence of aluminum and iron in the structure of the powders resulted in further amorphization. The obtained samples showed high specific surface areas (SSAs), ranging from 162.3 to 186.6 m²/g for MCM-41-HA and from 112.6 to 127.2 m²/g for AlMCM-HA. The hysteresis loops were found to be of type H3, indicating the formation of slit-like pores in the intercrystalline space, as confirmed by transmission electron microscopy, which revealed the presence of lamellar and flake-like particles. Catalytic activity tests showed that the conversion of dibenzothiophene depended on the iron concentration in the material and the acidity of the support. To further improve the catalytic activity of the materials, they were impregnated with molybdenum compounds. Active molybdenum peroxo complexes formed under these conditions enabled 100% conversion of dibenzothiophene. To our knowledge, this is the first study on the influence of MCM-41-HA- or AlMCM-HA-based materials on dibenzothiophene conversion via oxidative desulfurization using hydrogen peroxide as an oxidant. Full article

The present study aims to prepare a composite via pyrolysis, based on sodium alginate (SA) and a natural clay collected from the eastern region of Morocco, specifically the OUJDA area (C.O.R), for use in the disposal process of emerging pharmaceuticals. The strategy of rapid microwave heating followed by nitrogen calcination at 500 °C was successfully applied to produce the pyrolyzed carbonaceous materials. The removal of paracetamol (PCT) by adsorption on the carbonaceous clay (ca-C.O.R) composite was investigated to determine the effect of operating parameters (initial contaminant concentration, contact time, pH, and temperature) on the efficiency of PCT removal. The nanocomposite was analyzed using various techniques, including the nitrogen gas adsorption–desorption isothermal curve, X-ray diffraction, scanning electron microscopy, and Fourier transform infrared spectroscopy. Three models were used to describe the kinetic adsorption, and it was found that the experimental kinetic data fit well with a pseudo-second-order kinetic model with a coefficient of determination R² close to one, a nonlinear chi-square value close to zero, and a reduced root mean square error RMSE (R² → 1, X² → 0 and lower RMSE). The adsorption was best described by the Sips isotherm. The ca-C.O.R composite achieved a PCT removal efficiency of 91% and a maximum adsorption capacity of 122 mg·g⁻¹ improving on the performance of previous work. Furthermore, the variation in enthalpy (∆H°), Gibbs free energy (∆G°), and entropy (∆S°) indicated that the adsorption is exothermic in nature. The composite has shown promising efficiency for the adsorption of PCT as a model of emergent pollutant from aqueous solutions, making it a viable option for industrial wastewater treatment. Using Density Functional Theory (DFT) along with the 6-31G (d) basis set, the geometric structure of the molecule was determined, and the properties were estimated by analyzing its boundary molecular orbitals. The adsorption energy of PCT on MMT and ca-C.O.R studied using the Monte Carlo (MC) simulation method was −120.3 and −292.5 (kcal·mol⁻¹), respectively, which shows the potential of the two adsorbents for the emerging product. Full article

Niobium-based oxides are being increasingly evaluated as materials for energy storage applications. Additionally, the use of these oxides as cathodes in aqueous electrolytes has shown promise. Based on this, the pseudocapacitive behavior of protonic niobate nanowires in an aqueous acidic electrolyte (1 M H₂SO₄) was evaluated for the first time. The material was obtained in two simple sequential steps. First, hydrothermal synthesis resulted in sodium niobate; second was ionic exchange (in two concentrations of 2 M and 0.1 M HNO₃), where the protonic niobate was obtained. The resulting protonic niobate was characterized by FEG-SEM, the results demonstrated that the morphology of the oxide was concentration-dependent in the ionic exchange step, and EDS analysis was used to validate the procedure. Using DRX, Raman spectroscopy, and FTIR analysis, the transformation of sodium niobate to protonic niobate was evidenced. The electrochemical tests demonstrated that the protonic niobate presented pseudocapacitive behavior when employed as the cathode in 1 M H₂SO₄, and the ionic exchange in 2 M HNO₃ promoted a better specific capacitance, reaching 119.8 mF·cm⁻² at a 1 mA·cm⁻² current density. Full article

Additive manufacturing (AM) of ceramics presents a promising approach for the production of complex sanitaryware prototypes, offering advantages in terms of cost and time to market. This study explores binder jetting (BJ) as an optimal AM technique due to its ability to process ceramic materials without thermal stress, accommodate various compositions, and produce large components without support structures. A combination of refractory cement, feldspathic sands, quartz, and calcined alumina was used to formulate 19 different compositions, ensuring adequate green strength and minimizing shrinkage during sintering. A hydration-activated binding method with a water-based binder was employed to enhance part formation and mechanical properties. The results indicate that compositions containing calcined alumina exhibited lower pyroplastic deformation, while optimized gelling agent concentrations improved green strength and dimensional accuracy. The final selected material (SA18) demonstrated high compressive strength, low shrinkage, and a surface roughness comparable to traditional sanitaryware. The application of an engobe layer improved glaze adherence, ensuring a homogeneous surface. This study highlights binder jetting as a viable alternative to traditional ceramic processing, paving the way for its adoption in industrial sanitaryware manufacturing. Full article

This study investigates the application of spinel (MgAl₂O₄) hollow fiber membranes for clarification of clove basil (Ocimum gratissimum L.) aqueous extract, a rich source of bioactive compounds. The membranes were produced using a phase-inversion and sintering method at 1350 °C, combining alumina and dolomite as raw materials. The calcination of the powder materials at 1350 °C resulted in the spinel phase formation, as indicated by the XRD analyses. The spinel hollow fiber membrane presented a hydrophilic surface (water contact angle of 74°), moderate roughness (144.31 ± 12.93 nm), and suitable mechanical strength. The ceramic membrane demonstrated a water permeability of 35.28 ± 2.46 L h⁻¹ m⁻² bar⁻¹ and a final permeate flux of 9.22 ± 1.64 L h⁻¹ m⁻² for filtration of clove basil extract at 1.0 bar. Fouling analysis identified cake formation as the dominant mechanism for flux decline. The membrane retained 44% of the total phenolic compounds and reduced turbidity by 60%, while preserving significant antioxidant capacity in the permeate. The results highlight the potential of spinel-based hollow fiber membranes as a cost-effective and efficient solution for clarifying bioactive plant extracts, offering enhanced mechanical properties and lower sintering temperatures compared to conventional alumina membranes. Full article

In recent years, climate change has attracted the attention of the scientific community. These changes are attributed to human action, which is responsible for the emission of polluting gases, mainly through the burning of fossil fuels, deforestation, and industrial processes that are responsible for the greenhouse effect. Post-combustion CO₂ capture using solid adsorbents is a technology that is currently gaining prominence as an alternative and viable form of capture to other industrial processes used. Zeolites are adsorbents capable of capturing CO₂ selectively due to their properties such as textural properties, high surface area, and active sites. In this context, this work developed materials with a zeolite structure with an alternative low-cost silica source from beach sand, called MPI silica, to make the process eco-friendly. Crystallization time studies were carried out for materials containing MFI-type zeolites with MPI silica with a time of 15 h (ZM 15 h) and 3 days (SM 3 d), with relative crystallinities of 92.90% and 111.90%, respectively. The synthesized materials were characterized by several techniques such as X-ray diffraction (XRD), X-ray fluorescence (XRF), the textural analysis of N₂ adsorption/desorption isotherms, absorption spectroscopy in the infrared region with Fourier transform (FTIR), scanning electron microscopy (SEM), and thermal analysis. The evaluation of the experimental adsorption isotherms showed that the best results were for the zeolites synthesized in the basic medium, namely ZMP 3 d, ZM 10.5 h, and ZM 15 h, with capacities of 3.72, 3.10, and 3.22 mmol/g of CO₂, respectively, and in the hydrofluoric medium, namely SP 9 d, SM 3 d, and SM 6 d, with capacities of 3.94, 3.78, and 3.60 mmol/g of CO₂, respectively. The evaluation of the mathematical models indicated that the zeolites in the basic medium best fitted the Freündlich model, namely ZMP 3 d, ZM 10.5 h, and ZM 15 h, with capacities of 2.56, 1.68, and 1.87 mmol/g of CO₂, respectively. The zeolites in the hydrofluoric medium are adjusted to the Langmuir model (SP 9 d and SM 3 d) and Temkin model (SM 6 d), with capacities of 3.79, 2.23, and 2.11 mmol/g of CO₂, respectively. Full article

Copper niobate (CuNb₂O₆) is an important compound due to its low cost and polymorphism, presenting monoclinic and orthorhombic phases, which leads to unique physical–chemical properties. The electrochemical performance of efficient electrocatalysts for the oxygen evolution reaction (OER) is of importance in order to produce hydrogen gas from water. In this context, this work reports the synthesis of CuNb₂O₆ particles by high-energy milling for 5 and 10 h, and subsequent thermal treatment at 900 °C for 3 h. The samples were characterized by XRD, XRF, FESEM, RAMAN, UV–Vis, and FT-IR techniques, and were applied as electrocatalysts for the OER. The samples had both monoclinic and orthorhombic crystalline phases. The band gaps were in the range of 1.92 to 2.06 eV. In the application for the OER, the particles obtained by 5 and 10 h of milling exhibited overpotentials of 476 and 347 mV vs. RHE at 10 mA cm⁻², respectively. In chronopotentiometry experiments for 15 h, the samples exhibited excellent chemical stability. The electrochemical performance of the sample milled for 10 h showed superior performance (347 mV vs. RHE) when compared with electrocatalysts of the same type, demonstrating that the methodology used to synthesize the samples is promising for energy applications. Full article

This study investigates the upcycling of disposable face masks, which were produced in vast quantities during the COVID-19 pandemic and are now widely stockpiled in public institutions, destined for landfills after reaching expiration dates. The research focuses on incorporating shredded mask fibers into geopolymer matrices, evaluating the effects on mechanical and thermal properties to develop sustainable, high-performance materials. This approach addresses critical environmental, social, and economic challenges by transforming problematic waste into valuable resources while promoting sustainable building practices, such as developing insulating products for the construction industry. Mechanical testing demonstrated that adding shredded mask fibers (2 mm and 6 mm in size, up to 5 wt.%) enhanced the flexural strength of geopolymeric products. The optimal performance was achieved by adding 3 wt.% of 2 mm-length fibers, resulting in a flexural strength of 4.56 ± 0.23 MPa. Regarding compressive strength, the highest value (54.78 ± 2.08 MPa) was recorded in geopolymers containing 1 wt.% of 2 mm fibers. Thermal insulation properties of the materials improved with higher mask content, as evidenced by reductions in thermal conductivity, diffusivity, and specific heat. The lowest thermal conductivity values were observed in geopolymers containing 5 wt.% (0.4346 ± 0.0043 W·m⁻¹·K⁻¹) and 3 wt.% (0.6514 ± 0.0002 W·m⁻¹·K⁻¹) of 2 mm mask fibers. To further enhance thermal insulation, geopolymers with 5 wt.% mask fibers were foamed using H₂O₂ to obtain highly porous light materials, obtaining a reduction of thermal conductivity (0.3456 and 0.3710 ± 0.0007 W·m⁻¹·K⁻¹). This research highlights the potential of integrating fibrous waste materials into advanced construction technologies, offering solutions for waste reduction and development in the building sector toward sustainability. Full article

Molecularly imprinted polymers (MIPs) are synthetic polymers designed to exhibit selective recognition and binding capabilities toward target molecules and have been widely combined with advanced ceramic-based materials toward better performance in many catalytic applications of interest and beyond. What sets MIPs apart is their molecularly imprinted cavities, which are formed during polymerization in the presence of a template molecule. Upon template removal, these cavities retain the shape, size, and chemical functionality of the template molecule, allowing for highly specific recognition and binding of target molecules. In recent years, there has been a growing interest in leveraging these molecularly imprinted cavities not only for molecular recognition and sensing but also as catalytic sites and supports. Complementary to experimental studies, density functional theory (DFT) calculations are increasingly used to elucidate the molecular interactions, catalytic mechanisms, and optimize the design of MIP–ceramic catalysts. This review aims to provide a comprehensive overview of the current state of research on advanced ceramic-based catalysts supported by MIPs for environmental applications. Additionally, the review will discuss challenges and future directions in the field, focusing on enhancing the catalytic efficiency, stability, and scalability of MIP-based ceramic catalysts. By exploring these aspects, this review seeks to illustrate the promising role of MIP-modified ceramic materials in advancing the field of catalysis and catalytic supports. Full article

In this study, CdWO₄/CdMoO₄ powders’ heterostructures were synthesized using the microwave-assisted hydrothermal method, characterized, and evaluated for their photocatalytic properties. The samples were analyzed using X-ray diffraction (XRD), Raman and ultraviolet-visible (UV-Vis) spectroscopy, field-emission scanning electron microscopy (FESEM), and photoluminescence (PL). The photocatalytic performance was assessed using methylene blue as a model pollutant. XRD patterns and Raman spectra confirmed the formation of heterostructures containing the Wolframite phase of CdWO₄ and the Scheelite phase of CdMoO₄. FESEM micrographs revealed that the CdWO₄ phase exhibits a plate-like morphology, while the CdMoO₄ phase consists of irregular nanoparticles. Photocatalytic tests demonstrated that the 20Mo sample exhibited the best performance, degrading 96% of the dye after 2 h of reaction. The findings of this study indicate that CdWO₄/CdMoO₄ heterostructures hold significant potential for photocatalytic applications in the degradation of cationic dyes. Full article

The wear of hip prostheses represents a significant challenge for the longevity and functionality of joint implants. Recent studies have explored surface texturing of prostheses as a strategy to enhance tribological performance. This study aims to evaluate the impact of textured ceramic surfaces with dimples on wear and friction reduction in ceramic-on-ceramic (CoC) prostheses. Materials and Methods: Three-dimensional models of ceramic surfaces with and without dimples were created. Contact pressure was analyzed and wear volume was estimated using Archard’s law. Simulations were conducted using finite element methods (FEM) under various loading conditions. Results: Numerical simulations demonstrated that the wear rate for the dimpled femoral head was 0.2369 mm³/year, compared to 0.286 mm³/year for the smooth counterpart, highlighting a wear reduction of 17.2%. Conclusions: The integration of textured surfaces with dimples in ceramic prostheses can substantially improve their functionality and durability, representing a promising approach to addressing the issues associated with hip prosthesis wear. Full article

For decades, metal alloys have played a crucial role in medicine and dentistry as restorative materials. To enhance corrosion resistance and mitigate undesirable biological reactions, surface modifications of these alloys are widely employed. This study investigates the corrosion resistance and adhesion properties of a NiCr dental alloy coated with a Si(C,N) layer. The findings suggest that these coatings hold potential as protective layers for prosthetic components in future applications. Si(C,N) coatings were deposited using the reactive magnetron sputtering (RMS) method on the surface of a NiCr dental alloy. Four different carbon-to-nitrogen (C/N) ratio variations were examined. The results indicate that Si(C,N) coatings deposited via magnetron sputtering exhibit relatively low porosity (approximately 3%), enabling them to function effectively as barrier coatings. Among the tested coatings, the Si(39.6C/25.2N) layer demonstrated the highest polarization resistance (R_p) value and the lowest corrosion current density (i_cor), corrosion rate (CR), and mass loss rate (MR), suggesting that this composition achieves an optimal balance between carbon and nitrogen content. These findings are promising for the potential application of Si(C,N) coatings in dental techniques. Full article

This work systematically analyses the electrical and structural properties of a bilayer gate dielectric composed of Sm₂O₃ and ZrO₂ on a 4H-SiC substrate. The bilayer thin film was fabricated using a sputtering process, followed by a dry oxidation step with an adjusted oxygen-to-nitrogen (O₂:N₂) gas concentration ratio. XRD analysis validated formation of an amorphous structure with a monoclinic phase for both Sm₂O₃ and ZrO₂ dielectric thin films. High-resolution transmission emission (HRTEM) analysis verified the cross-section of fabricated stacking layers, confirmed physical oxide thickness around 12.08–13.35 nm, and validated the amorphous structure. Meanwhile, XPS confirmed the presence of more stoichiometric dielectric oxide formation for oxidized/nitrided O₂:N₂-incorporated samples, and more sub-stochiometric thin films for samples only oxidized in ambient O₂. The oxidation/nitridation processes with N₂ incorporation influenced the band offsets and revealed conduction band offsets (CBOs) ranging from 2.24 to 2.79 eV. The affected charge movement and influenced electrical performance where optimized samples with gas concentration ratio of 90% O₂:10% N₂ achieved the highest electrical breakdown field of 10.1 MV cm⁻¹ at a leakage current density of 10⁻⁶ A cm⁻². This gate stack also improved key parameters such as the effective dielectric constant ($k_{eff}$) up to 29.75, effective oxide charge ($Q_{eff}$), average interface trap density ($D_{it}$), and slow trap density (STD). The bilayer gate stack of Sm₂O₃ and ZrO₂ revealed potential attractive characteristics as a candidate for high-k gate dielectric applications in metal-oxide-semiconductor (MOS)-based devices. Full article

Nowadays, the global brick industry utilizes billions of cubic meters of clay soil annually, resulting in the massive consumption of non-renewable resources. This study explores the viability of utilizing red marl from phosphate mining waste rocks for fired brick production. Ecofriendly fired bricks produced from 100% side streams (red marly clays (RM) and marble waste powder (MWP)) were prepared, pressed, dried at 105 °C, and then fired at 1100 °C for 1 h. The effects of marble waste powder addition (up to 30 wt%) on the physical, mechanical, mineralogical, and microstructural properties of the fired bricks were explored. The main results show that fired bricks with high compressive strength of a maximum of 39 MPa could be prepared with a mixture of red marl and 10 wt% of marble waste powder. The thermal conductivity was decreased by marble waste addition (from 0 to 30%) and was reduced from 0.93 W/m.k to 0.53 W/m.k; however, the compressive strength was also decreased to reach a minimum of 17 MPa. The firing shrinkage and density were also reduced with 30% marble waste by 41% and 18%, respectively. Therefore, red marly clays and marble waste could be promising raw materials for eco-fired brick production. Full article

Several studies have demonstrated that 3D-printed geopolymer concrete (3DPGPC) could be a sustainable solution to minimising waste, carbon emissions, and production costs, thereby providing quick completion of construction projects. However, for 3DPGPC to be widely adopted, it is essential to be aware of both the prospects as well as the limitations. In this regard, the scope of this perspective article includes a review of the limitations of 3DPGPC. Key limitations regarding the material, structural, technical, economic, and environmental aspects of 3DPGPC are highlighted. Additionally, this article includes the general limitations associated with geopolymer concrete. As such, geopolymer concrete suffers from several problems owing to varying alkaline activators and precursor types while exhibiting performance variability even within the same type of precursor. These limitations need to be addressed first in order to make progress in 3DPGPC. Following the limitations, this article then presents the research priorities in 3DPGPC, such as the need for a standardised code for its adoption in infrastructure projects. Hence, the information presented in this article is timely and crucial for all stakeholders in the low-carbon community. Furthermore, it serves as a call for future research to overcome the discussed limitations to realise the full potential of 3DPGPC technology. Full article

Herein, we present in-depth investigations of the biological activities of a CaO/NiO nanocomposite synthesized via a sustainable eco-friendly approach, utilizing Citrus limonium fruit extract as a natural stabilizing and facilitating agent. The efficacy of the nanocomposite is compared with those of individual CaO and NiO nanoparticles. X-ray diffraction analysis confirms the cubic phase of CaO as well as NiO within a unified matrix, demonstrating a refined crystallite size of 48 nm, which is smaller than that of the individual nanoparticles. FTIR study substantiates the occurrence of strong Ca-O-Ni-O bonds, along with CO₃²⁻, C–H, and CH₂ bonds. The CaO, NiO, and CaO/NiO samples exhibit bandgap values of 1.70, 3.46, and 3.44 eV, respectively. Surface morphology analysis reveals that CaO/NiO holds a well-defined heterostructure with porous morphology. An XPS study confirms that Ca and Ni elements exist in the 2+ oxidation state in the CaO/NiO. The nanocomposite exhibits superior antibacterial activity, with inhibition zones of 24.3 mm against Bacillus subtilis and 20.6 mm against Salmonella typhi, and MIC values of 23.4 and 46.8 µg/mL, respectively. It also demonstrates strong antioxidant potential, with IC₅₀ values of 96.8 ± 0.4 µg/mL (DPPH) and 91.8 ± 0.1 µg/mL (superoxide anion). Furthermore, it shows the lowest IC₅₀ for α-amylase (98.6 ± 0.7 µg/mL) and strong α-glucosidase inhibition (81.96 ± 0.5 µg/mL). Consequently, this insightful study reveals how biogenic synthesis helps develop high-performance multifunctional CaO/NiO nanocomposites for biomedical applications. Full article

This study presents the green synthesis and comprehensive characterization of ZnO–Ag nanocomposites using an eco-friendly approach that incorporates aqueous Tagetes erecta extract via the co-precipitation method. The research systematically evaluates the effect of silver concentration (0.1–0.5%) on material properties and dual applications: solar photocatalytic degradation of methylene blue and antibacterial activity against both Gram-positive (Staphylococcus aureus) and Gram-negative (Escherichia coli) bacteria. Advanced characterization techniques, including UV-Vis, XRD, TEM, FTIR, and TGA, confirmed the successful formation of crystalline nanocomposites with spherical and hemispherical morphologies, consisting of hexagonal wurtzite ZnO and face-centered cubic Ag phases. Results demonstrate that strategic silver incorporation significantly enhances ZnO photocatalytic activity by improving charge separation and reducing recombination rates, with the ZnO–Ag (0.3%) nanocomposite exhibiting optimal performance, achieving complete methylene blue degradation within 25 min under solar irradiation. Antibacterial assays showed efficacy against the bacteria used, with a significantly stronger bactericidal effect against S. aureus than E. coli, especially for ZnO–Ag (0.2%) at a 250 μg/mL concentration. This study highlights the synergistic effect between ZnO, Ag, and bioactive compounds from Tagetes erecta, offering a sustainable approach for developing multifunctional nanomaterials with significant potential in environmental remediation and antibacterial applications. Full article

In this study, we highlight the use of the alkaline earth metal barium (Ba) for the impregnation of Ag₃PO₄ (AgP). AgP was synthesized via co-precipitation and subsequently impregnated with a Ba²⁺-containing solution, followed by hydrothermal treatment to obtain Ba-AgP. The addition of barium significantly influenced both the crystallinity and crystallite size. Ba impregnation enhanced the crystallinity of AgP and promoted the growth of its crystallites. It was confirmed that Ba²⁺ was homogeneously distributed on the surface of AgP, with only a slight effect on particle shape. Ba-impregnated Ag₃PO₄ (Ba-AgP) exhibited improved photocatalytic activity for the degradation of methyl orange (MO) under visible light compared to bare AgP. The optimal impregnation concentration of Ba²⁺ was determined to be 6%. This enhancement is attributed to the role of Ba²⁺ in facilitating the separation of photogenerated electron–hole pairs, which also contributed to the improved stability of AgP. The active species h⁺, ·OH, and O₂·⁻ were all identified as essential for the MO degradation process, with h⁺ being the most significant contributor. Full article

Silicon carbide (SiC) is a highly valued material in structural ceramics due to its exceptional properties, including low thermal expansion, high mechanical strength, thermal conductivity, hardness, and corrosion resistance. These attributes make SiC suitable for a wide range of applications, from filters and electrodes to refractory and structural materials. In this study, SiC samples were produced under various conditions and characterized through techniques such as diffraction, SEM, TGA, and optical microscopy. The results indicated a band gap of 3.195 eV, an apparent density of 1.317 g/cm³, and Vickers hardness ranging from 1193 to 536 HV. Additionally, the Young’s modulus of the sample was found to be 0.4 GPa. These findings demonstrate the potential of starch consolidation for the cost-effective production of SiC ceramics with promising mechanical properties. Full article

SiAlCN coatings were first obtained by the method of reactive evaporation of aluminum and plasma chemical activation of an organosilicon precursor in a hollow cathode arc discharge. The spectrum of discharge plasma was studied by optical emission spectroscopy under conditions of evaporation of Al in an Ar+N₂+hexamethyldisilazane vapor/gas medium, and it was shown that in the presence of a metal component in the plasma, not only did intensive activation of various components of the media occur but also an increased ionic effect on the surface of the coating was provided, with a deposition rate of up to 10.1 µm/h. The films had a dense and homogeneous structure and had a hardness of up to 31 GPa and good adhesion on stainless steel. The results of SEM, FTIR, and XRD showed that their structure was a nanocomposite consisting of an amorphous matrix based on SiCN and AlN with inclusions of AlCN nanocrystals. Full article

In this study, the structural, electronic, and elastic properties of cubic zirconium dioxide (c-ZrO₂) were investigated using the Density Functional Theory (DFT) approach. Lattice parameter optimization revealed that the lattice constant is 5.107 Å, the Zr–O bond length is 2.21 Å, and the unit cell density is 6.075 g/cm³ for the B3LYP functional. The bandgap width was determined to be 5.1722 eV. The investigation of the elastic properties of the cubic ZrO₂ crystal determined the Young’s modulus, bulk modulus, Poisson’s ratio, and hardness, which were found to be 315.91 GPa, 241 GPa, 0.282, and 13 (Hv), respectively, under zero external pressure. These results confirm the mechanical stability of ZrO₂. Full article

Nickel-doped iron oxide/graphene oxide powders were synthesized by the co-precipitation method varying the Ni/Fe ratio, and the activity of the materials towards the oxygen reduction reaction in a microbial fuel cell (MFC) was studied. The samples presented X-ray diffraction peaks associated with magnetite, maghemite and Ni ferrite, as well as evidence of hematite. Raman spectra confirmed the presence of maghemite (γ-Fe₂O₃) and NiFe₂O₄. Scanning electron micrographs showed exfoliated sheets decorated with nanoparticles, and transmission electron micrographs showed spherical nanoparticles about 10 nm in diameter well distributed on the individual graphene sheet. The electrocatalytic activity for the oxygen reduction reaction (ORR) was studied by cyclic voltammetry in an air-saturated electrolyte, finding that the best catalyst was the sample with a 1:2 Ni/Fe ratio, using a catalyst concentration of 15 mg·cm⁻² on graphite felt. The 1:2 Ni/Fe catalyst provided an oxygen reduction potential of 397 mV and a maximum oxygen reduction current of −0.13 mA; for comparison, an electrode prepared with GO/γ-Fe₂O₃ showed a maximum ORR of 369 mV and a maximum current of −0.03 mA. Microbial fuel cells with a vertical proton membrane were prepared with Ni-doped Fe₃O₄ and Fe₃O₄/graphene oxide and tested for 24 h; they reached a stable OCV of +400 mV and +300 mV OCV, and an efficiency of 508 mW·m⁻² and 139 mW·m⁻², respectively. The better performance of Ni-doped material was attributed to the combined presence of catalytic activity between γ-Fe₂O₃ and NiFe₂O₄, coupled with lower wettability, which led to better dispersion onto the electrode. Full article

The introduction of side-emitting lenses into white light-emitting diodes (LEDs) has enabled thin panel lighting technology based on LED technology, but also presents the disadvantage of low color rendering due to insufficient red components in the spectra of typical white LEDs. Additional application of remote quantum dot (QD) components such as QD films or caps presents the issues of increased numbers of components and higher costs. In this study, we incorporated red QDs directly into a lens placed on white LEDs and analyzed the effects of QD lenses on the optical characteristics of a lighting device through experiments and simulations. By incorporating red CdSe/ZnS QDs into UV-curable resin to fabricate QD lenses and applying them to white LEDs, we significantly improved the color rendering index and were able to adjust the correlated color temperature over a wide range between 2700 and 9900 K. However, as the concentration of QDs in the lens increased, scattering by the QD particles was enhanced, strengthening the Lambertian distribution in the intensity plot. Following the development of optical models for QD lenses under experimental conditions, comprehensive optical simulations of white LED lighting systems revealed that increasing the device height proved more effective than modifying TiO₂ scattering particle concentration in the diffuser plate for mitigating QD-induced bright spots and enhancing illumination uniformity. Full article

This paper presents research findings on the turning of AZ31B magnesium alloy using ceramic-coated tungsten carbide tool inserts in a dry environment. Fifteen experiments were conducted according to the Box–Behnken design (BBD) for the straight turning of AZ31B magnesium alloy to investigate the variations in two important machinability indicators, i.e., material removal rate ‘MRR’ and mean roughness depth ‘R_Z’, with variations in cutting speed ‘C_S’, feed rate ‘f_r’, and depth of cut ‘DoC’. The cutting speed and feed rate had the maximum influence on the mean roughness depth and material removal rate, respectively. To address the challenge of optimizing conflicting machining responses, desirability function analysis (DFA) and grey relational analysis (GRA) were employed to identify the optimal turning parameters for conflicting machinability indicators or responses. These techniques enabled the simultaneous maximization of the material removal rate and the minimization of the mean roughness depth, ensuring an effective balance between productivity and surface quality. The optimal turning conditions—cutting speed of 90 m/min, feed rate of 0.2 mm/rev, and depth of cut of 1.0 mm—yielded the best multiperformance results with an MRR of 18,000 mm³/min and an R_Z of 2.21 µm. Scanning electron microscope (SEM) analysis of the chip and flank surface of the cutting tool insert used in the confirmation tests revealed the formation of band-saw-type continuous chips and tool wear caused by adhesion and abrasion. Full article

In the Amazon region, bauxite processing generates significant quantities of clay mineral-rich tailings, which pose a major challenge for bauxite mining operations. This study explores the use of bauxite tailings to produce fired bricks and evaluates their properties. Using a Box–Behnken experimental design, nine specimens were prepared with varying granite content (0%, 5%, 10%, 20%, and 30%) and fired at three different temperatures: 800 °C, 900 °C, and 1000 °C. The bauxite tailings contain gibbsite, kaolinite, Al-goethite, and hematite, while the granite powder comprises quartz, potassium feldspar, sodium plagioclase, muscovite, and occasionally kaolinite. Linear shrinkage values remained within recommended limits, below 8%. Apparent porosity (AP) results ranged from 60.2% to 72%, with maximum water absorption reaching 23.6%. The compressive strength of bricks without granite addition was 11.9 MPa at 900 °C, with the highest value recorded at 14.9 MPa at 800 °C when granite was added. These findings indicate that bauxite tailings, when supplemented with pulverized granite, exhibit promising potential for fired brick production. Full article

Radiation transfer in layers of densely packed aggregates of hydroxyapatite nanoparticles was studied for a spectral range from 300 to 1100 nm using diffuse reflectance measurements and the modeling of the light transfer properties of the layers. The studied samples of dispersed biogenic hydroxyapatite were obtained from animal bone material (bovine bones) using fast pyrolysis followed by grinding and pressing into tablets. A distinctive feature is the high reflectivity (high albedo) of the obtained samples, which is practically independent of the wavelength in the studied spectral range and comparable to the reflectivity of the diffuse reflectance standard based on Spectralon. The modeling of the light transfer properties of the studied samples within the framework of the effective medium theory (using coherent potential approximation) made it possible to establish the weak dependence of the mean scattering-free path and the mean transport-free path of light propagation in the medium on the wavelength, which is consistent with the features observed in the experiment. Possible prospects for the use of nanostructured hydroxyapatite as photonic material are discussed. Full article