Search Results (748)

The Lantana genus, especially L. camara, has emerged as a potential yet underutilized lignocellulosic feedstock for various catalytic thermochemical conversion products and advanced carbon materials. This study reviews recent developments in the valorization of Lantana biomass to generate biofuels, bio-oil, syngas, and engineered biochar materials through pyrolysis, gasification, hydrothermal processing, and integrated biorefinery processes, in a critical manner. Particular focus will be on nanocomposite-modified, metal-doped biochar with catalytic elements such as ZSM-5, Fe₃O₄, TiO₂, and Ni-, Co-, and Zn-based oxides to enhance deoxygenation, catalytic cracking, tar reforming, pollutant remediation, and energy storage. Recent developments in catalyst synthesis techniques, such as impregnation, hydrothermal deposition, and in situ functionalization, are reviewed, along with characterization methods including BET, XRD, SEM/TEM, Raman spectroscopy, and XPS. The review further examines the impact of pore structure, surface chemistry, the presence of redox-active centers, and catalyst stability on product selectivity, syngas quality, and upgrading bio-oil performance. The effects of biochar on microbial immobilization, anaerobic digestion, and integrated biochemical conversion are discussed in detail, excluding thermochemical effects. The challenges of catalyst deactivation, biomass heterogeneities, scalability, techno-economic viability, and decentralized biomass logistics are also discussed. In summary, the development and implementation of catalytic reaction engineering, the design of nanocomposite biochar, and circular bioeconomy strategies have great potential to facilitate the conversion of invasive Lantana biomass into renewable fuels, multifunctional carbon materials, and environmentally friendly bioeconomy products. Full article

This study focuses on sustainable atmospheric water harvesting (AWH) using film-containing green nanomaterials. Particular emphasis is given to chitosan as a sustainable biopolymer matrix due to its intrinsic hydrophilicity, biodegradability, film-forming ability and abundance of amino and hydroxyl functional groups that favor water adsorption and nanoparticle interaction. ZnO, SiO₂ and Fe-Zn-SiO₂ nanoparticles with abundant hydroxyl groups were synthesized from plant-based materials such as biomass from peanut and banana wastes, as well as plant extracts. Nanocomposite membranes containing nanoparticles with a high specific surface area and moisture-sensitive behavior were successfully developed. Results showed that bilayer films outperformed monolayer systems in water harvesting performance. In particular, the bilayer film composed of Chitosan/G-ZnO (10 wt.%) on the top layer and Chitosan/G-SiO₂ (10 wt.%) in the bottom layer displayed outstanding hydrophilic properties with water contact angles reduced to 42–43°. The material demonstrated an equilibrium adsorption capacity for water at 0.90 g/g and a passive yield of 1.5–2.2 mL/g per day. The improved adsorption behavior was attributed to the synergistic effect between the hydroxyl-rich oxide nanoparticles, the intrinsic water affinity of chitosan, and the layered porous structure. Moreover, the samples showed good thermal and mechanical stability and retained their structure after several uses. These findings highlight the potential of chitosan-centered green nanocomposites as sustainable materials for passive AWH applications. Full article

Background: Hydrogel membranes are highly effective biomaterials with huge potential for advanced wound management, offering the dual advantage of maintaining a beneficial moist environment while serving as a localized reservoir for antibacterial agents. Zinc oxide nanoparticles (ZnO NPs) are particularly notable in this regard, possessing potent antibacterial capabilities and intrinsic tissue-healing properties. Methods: In this study, we report the successful fabrication of a novel locust bean gum (LBG) hydrogel encapsulated with ZnO NPs, utilizing AlCl₃ as a cross-linking agent. The synthesized nanocomposite hydrogels were structurally and chemically characterized using Scanning Electron Microscopy (SEM) and Fourier-Transform Infrared Spectroscopy (FTIR) followed by in vivo studies using experimental animals by creating wound model. Results: Physicochemical evaluations revealed a concentration and pH-dependent swelling profile, achieving a maximum swelling capacity of 97% at pH 9. In vitro kinetic studies depicted a highly desirable initial burst release of the active therapeutic, subsequently followed by a continuous, sustained release phase that was strictly governed by non-Fickian diffusion mechanics. Furthermore, the optimized formulations achieved excellent entrapment efficiencies (>95%) and substantial free-radical scavenging antioxidant potential (>86%). Biological assessments confirmed the safety and efficacy of the nanocomposites. The formulations exhibited zero cellular toxicity against fibroblast cell lines and demonstrated complete biocompatibility during tissue histopathological evaluations. Significant antimicrobial activity was also observed, as demonstrated by reduction in the Minimum Inhibitory Concentration (MIC) against critical pathogens, including S. aureus, E. coli, P. aeruginosa, and resistant MRSA strains. Crucially, in vivo studies using experimental animal models demonstrated accelerated tissue remodeling, achieving complete wound healing by day 11 and vastly outperforming the control groups. Finally, in silico molecular docking simulations corroborated these empirical findings, revealing strong and favorable binding interactions of the nanocomposite with key target proteins to elucidate its underlying antibacterial mechanisms. Conclusions: Collectively, these results establish the ZnO-loaded LBG hydrogel as a safe, multifunctional, and highly efficient topical drug delivery platform for cutaneous wound healing. Full article

The aim of this study was to investigate the impact of ZnO nanoparticles on the humidity-sensing properties of BiFeO₃ nanoparticles. BFO, ZnO, and x% ZnO-BiFeO₃ nanoparticles were synthesized using chemical processes and then analyzed by Scanning Electron Microscopy (SEM), X-Ray Diffraction (XRD), and Raman spectroscopy. The electrical capacitance of the sensors was measured using an impedance meter over a Relative Humidity (RH) range of 17 to 94% at room temperature and at an applied frequency of 100 Hz. This paper demonstrates that adding zinc oxide (ZnO) to bismuth ferrite (BFO) materials significantly improves the humidity response of BFO-based sensors. Indeed, a response of 2.8 × 10⁶% was achieved for 20% ZnO-BFO-based sensors, compared with 5.8 × 10³% for a pure BFO-based sensor. At the same time, a low hysteresis effect and excellent long-term stability were observed. In conclusion, the addition of ZnO nanoparticles provides excellent humidity-sensing properties to the BFO material, thereby contributing to its wide range of applications. Full article

Radiation therapy is widely used for cancer treatment. To improve therapeutic efficacy, traditional radiosensitizers are often used in combination. However, their toxic side effects necessitate urgent development of safer alternative biogenic radiosensitizers. Herein, a green approach was used to synthesise ZnO NPs, CuO NPs, and ZnO-CuO NCs using S. africana Luteus, and their ability to enhance the radiosensitizing effect of proton irradiation on Michigan Cancer Foundation-7 (MCF7) breast cancer cell line was evaluated. The biogenic nanoparticles are characterised in detail through several analytical techniques, including Ultraviolet-visible (UV-Vis) spectroscopy, X-ray diffraction (XRD), Fourier Transform Infrared (FTIR) spectroscopy, and Scanning Electron Microscopy (SEM). Interestingly, the NPs showed concentration-dependent effects on MCF7 viability, with CuO NPs exhibiting the strongest effect (IC₅₀ = 42.90 µg/mL), followed by ZnO-CuO NCs (71.12 µg/mL) and ZnO NPs (103.43 µg/mL). Proton irradiation produced a dose-dependent decrease in clonogenic survival of MCF7 cells, and ZnO-CuO NCs displayed the highest enhancement of proton-induced cell death, with a Dose Enhancement Factor (DEF) of 1.69, compared with CuO NPs (1.46) and ZnO NPs (1.09). Holotomographic microscopy (HTM) data further confirmed that ZnO-CuO NCs impaired cellular macromolecules more than the individual NPs. Findings from this study suggest that the biogenic NPs are promising radiosensitizers for cancer radiotherapy. Full article

Next-generation wastewater treatment and recycling rely on membrane-based processes, but they face a trade-off among permeability, selectivity, and fouling resistance. In the present study, thin-film nanocomposite (TFN) membranes were fabricated by incorporating a ternary TiO₂-SiO₂-biochar nanofiller into a polysulfone (PSf) support using nonsolvent-induced phase separation, after which m-phenylenediamine and trimesoyl chloride were used via interfacial polymerization to produce a selective polyamide layer. The membrane compositions were M1 (22 wt.% PSf), M2 (22 wt.% PSf/0.5 wt.% TiO₂/0.5 wt.% SiO₂/0.5 wt.% biochar), and M3 (polyamide-coated M2). FTIR, XRD, SEM, contact-angle, porosity, and mechanical analyses supported successful membrane formation and changes in morphology, wettability, and structural strength after nanofiller incorporation and TFC coating. The addition of a nanofiller increased the hydrophilicity of the membranes by decreasing the water contact angle from 98.6 ± 0.8° for pristine PSf to 35.6 ± 1.5° for the nanocomposite membrane. Consequently, the pure-water permeability increased from 21 to 37 L m⁻² h⁻¹ bar⁻¹. After polyamide layer formation, the optimized TFN membrane maintained a contact angle of 55.4 ± 3.8° and achieved a high Congo red rejection of 98% with permeate flux of 7–9 L m⁻² h⁻¹ bar⁻¹. The membrane also showed good antifouling performance, with flux recovery ratios exceeding 90%. For heavy-metal-containing solutions, the optimized membrane showed apparent removal efficiencies of 78–98% for multivalent heavy metals (Pb²⁺, Hg²⁺, Cd²⁺, Mn²⁺, Zn²⁺, Cu²⁺, Ni²⁺, Fe³⁺, As³⁺, and Cr⁶⁺). Static adsorption tests showed the order M2 > M3 > M1, confirming that exposed TiO₂-SiO₂-biochar sites contribute to pollutant uptake, while the superior filtration performance of M3 is attributed to the combined effect of the polyamide selective layer and adsorption-assisted interactions. Overall, the TiO₂-SiO₂-biochar-based TFN membrane provides a promising platform for dye removal and preliminary heavy-metal attenuation from contaminated water. Full article

The linear and third-order nonlinear optical (NLO) properties of a water-soluble perylenediimide derivative, N,N′-di(2-(trimethylammonium iodide) ethylene) perylenediimide (TAIPDI), doped with semiconductor nanoparticles (NPs), were systematically investigated under femtosecond laser excitation. ZnO and TiO₂ NPs were synthesized using a pulsed laser ablation technique. Nanocomposite systems were prepared by incorporating different concentrations of ZnO and TiO₂ NPs into the TAIPDI dye solution. The optical properties were characterized using UV–visible absorption spectroscopy together with open- and closed-aperture Z-scan measurements at 800 nm. Linear absorption measurements revealed concentration-dependent modifications in the optical band gap, indicating electronic interaction between the dye molecules and the semiconductor NPs. Open-aperture Z-scan results demonstrated strong nonlinear absorption (NLA) behavior dominated by two-photon absorption and excited-state absorption processes. Closed-aperture measurements showed a negative nonlinear refractive (NLR) index, corresponding to self-defocusing behavior. Both the NLA coefficient and the NLR index increased with increasing NP concentration, resulting in a significant enhancement of the third-order nonlinear susceptibility of the nanocomposite systems. In addition, optical limiting measurements revealed a pronounced reduction in the limiting threshold with increasing nanoparticle concentration, demonstrating improved laser attenuation capability. These findings indicate that ZnO@TAIPDI and TiO₂@TAIPDI nanocomposites are promising candidates for applications in optical limiting, all-optical switching, and advanced photonic devices. Full article

Imidacloprid (IMI), the commonly used neonicotinoid pesticide, has emerged as a persistent aquatic contaminant due to its high solubility and stability, posing risks to non-target organisms and ecosystem health. In this study, a MnZnFe₂O₄/SrWO₄ ferrite–tungstate nanocomposite was synthesized via a hydrothermal process and its ability to photocatalytically degrade IMI under UV light was assessed. SEM, XRD and FT-IR were used to characterize the composite to confirm its structural and morphological features. Photocatalytic performance was systematically investigated by examining the effects of operational factors, including initial pollutant concentration, catalyst dosage, pH, and irradiation time. The MnZnFe₂O₄/SrWO₄ nanocomposite exhibited significantly enhanced activity, achieving up to 87% degradation of IMI within 30 min at pH 9, outperforming individual components (SrWO₄: 37%; MnZnFe₂O₄: 75%) under identical conditions. The degradation kinetics followed a pseudo-first-order model consistent with the Langmuir–Hinshelwood mechanism. Effective interfacial charge transfer between the ferrite and tungstate phases, which suppresses electron-hole recombination and increases the production of reactive species, is responsible for the enhanced performance. Furthermore, the composite demonstrated good stability and reusability across several cycles, indicating its practical applicability. Overall, the results demonstrate the potential of MnZnFe₂O₄/SrWO₄ nanocomposites as efficient and sustainable photocatalysts for removing imidacloprid and similar organic contaminants from aqueous systems. Full article

Rising triple-negative breast cancer (TNBC) cases and Candida infection risks during chemotherapy demand novel therapies, with metal-oxide nanocomposites emerging as a promising solution. In this study, we synthesized Ag-ZnO and Cu-ZnO nanocomposites as established quantitative links between their physicochemical properties, ion release behaviour, and biological activity, evaluating antifungal effects against Candida albicans (ATCC 90028) and Saccharomyces cerevisiae (ATCC 9763), and their anticancer potential against MDA-MB-231 cells (ATCC HTB-26). The results revealed Ag (~13–19 nm) and Cu (~4–8 nm) nanoparticles dispersed in a ZnO matrix, with XPS confirming mixed Ag⁰/Ag(I)/Ag(III) and Cu(I)/Cu(II) speciation. Ag-ZnO NC exhibited strong antifungal activity (MIC = 25 mg L⁻¹) against both fungi, while Cu-ZnO NC was only effective (MIC = 100 mg L⁻¹) against S. cerevisiae. Aqueous release of Ag⁺ was ~2.6-fold higher than Cu²⁺. Ag-ZnO NC induced marked ROS generation (~6-fold higher than S. cerevisiae) and dehydrogenase inhibition (6.6- and ~20-fold, respectively). ATR-FTIR linked species-specific susceptibility to cell-wall architecture. SEM confirmed membrane destabilization and perforation. In MDA-MB-231, necrotic fractions reached ~9% and >40% for Ag-ZnO and Cu-ZnO, respectively. Both metal oxide nanocomposites (MONCs) act through ion release, revealing a selectivity window, especially for Ag-ZnO. Further studies on non-cancerous cells, ion-release kinetics, uptake and in vivo validation are essential to establish a therapeutic index. Full article

In this work, we employed an easy hydrothermal method to prepare CuO and ZnO, as well as the prepared composite nanostructured electrodes of CuO@ZnO for supercapacitor applications. The systematic electrochemical performance evaluation of the prepared materials was conducted by cyclic voltammetry (CV), galvanostatic charge–discharge (GCD), and electrochemical impedance spectroscopy (EIS). CuO@ZnO nanocomposite reflected the best charge storing behavior with a specific capacitance of 513 F/g, followed by pristine CuO (190 F/g) and ZnO (416 F/g). The composite also demonstrated 25.67 Wh/kg and 400 W/kg for energy density and power density, respectively, suggesting improved electrochemical performance. Besides, the areal and volumetric capacitances were 0.77 F/cm² and 4.81 F/cm³, respectively, supported by the structural integrity and enhancement in electroactive materials utilization of the electrode material. Kinetic analysis showed that b values of the samples had mixed capacitive/diffusion-controlled charge storage, while higher diffusion coefficients and standard rate constants were apparent for ion transport or redox kinetics. EIS results showed a 2.14 Ω solution resistance, indicative of a decreased electrical resistivity. An asymmetric supercapacitor device fabricated by CuO@ZnO as the positive electrode and activated carbon (AC) as the negative electrode provided the specific capacitance of 48.57 F/g, energy density of 15.17 Wh/kg, and power density of 535 W/kg. After 10,000 cycles, the capacitance of the device was 76%, indicating good long-term stability. Full article

Pesticides are widely used chemical compounds in agriculture, but their presence in water systems represents a significant environmental and health problem. Due to their stability and toxicity, many pesticides are difficult to remove using conventional water treatment methods, which has led to the development of advanced oxidation processes. Photocatalytic processes are based on the activation of semiconductor materials under light irradiation, leading to the formation of reactive species that degrade pesticides into less harmful products. On the other hand, electrocatalytic processes use electrical energy to generate oxidation and reduction reactions on electrode surfaces, enabling efficient degradation of organic pollutants. Both approaches offer high efficiency and the potential for complete mineralization of pesticides. Nanomaterials play a key role in improving these processes, as they provide a large specific surface area, enhanced conductivity, and increased reactivity. In photocatalysis, nanostructured metal oxides such as TiO₂ and ZnO are commonly used, while in electrocatalysis, advanced nanocomposites and modified electrodes are applied to improve electron transfer efficiency and system stability. This review paper provides an overview of recent research in the field of photocatalytic and electrocatalytic systems for pesticide removal from water, with a particular focus on the role of nanomaterials. Special attention is given to current trends, including the development of new nanostructures, hybrid systems, and energy-efficient technologies. The aim of this paper is to present, in a simple and clear way, the potential of these methods and to contribute to a better understanding of their application in environmental protection. Full article

Increasing environmental pollution has intensified the focus on sustainability, encouraging the development of eco-friendly materials. This study reports the synthesis of binary (ZnO–TiO₂) and ternary (SnO₂–ZnO–TiO₂) compounds and their loading with Au/Ag/Pt/P noble metals (NMs) to enhance photodegradation efficiency under visible light compared to pristine TiO₂. The compounds were synthesized in a single step via laser pyrolysis, and then noble metal deposition through chemical impregnation and reduction was performed. Structural and morphological analyses revealed TiO₂-based nanoparticles with varied morphologies decorated with noble metal nanoparticles with sizes between 2 and 6 nm (for Pt and Pd). Photocatalytic tests demonstrated a significant improvement in Methyl Orange (MO) degradation under visible light, especially for Ag-loaded samples. The degradation rate increased from 1.03 × 10⁻³ min⁻¹ (TZ) to 22.65 × 10⁻³ min⁻¹ (TZS_Ag), while it was 0.09 × 10⁻³ min⁻¹ for the commercial P25 sample. Biocompatibility assays indicated lower cytotoxicity than Degussa P25, with Au- and Pd-loaded samples showing improved compatibility with HaCaT and HEK293 cells. Overall, these findings demonstrate that the developed TiO₂-based nanocomposites, designed through a novel and sustainable strategy combining binary/ternary heterostructures with noble metal loading, are promising candidates for efficient visible light-driven photocatalytic environmental decontamination with enhanced biological compatibility. Full article

Developing a biodegradable film with integrated mechanical robustness and multifunctionality remains a significant challenge for sustainable food packaging. Herein, a pectin/carboxymethyl cellulose composite film (PNZ_xC) incorporated with zinc oxide nanoparticles (ZnO) was fabricated via a solution casting method to achieve the synergistic enhancement of structural and functional properties. ZnO exhibits dual functionality within the polymer matrix, serving both as a reinforcing filler and as a coordination interaction node via interactions with carboxyl groups. At an optimal loading, the PNZ₂C film demonstrates a uniform dispersion of nanoparticles, facilitating the development of a dense network structure and enhancing intermolecular interactions. Consequently, the film showed reduced water vapor and oxygen permeability, attributable to the formation of tortuous diffusion pathways, together with increased surface hydrophobicity and a significantly improved tensile strength of 25.4 MPa. Enhanced thermal stability and excellent UV-blocking performance were also achieved. Notably, the optimized film demonstrated superior preservation performance in blueberry storage, effectively reducing moisture loss and delaying quality deterioration compared with the control. These findings provide new insights into the structure–property relationships of ZnO–polysaccharide nanocomposite systems and highlight a viable strategy for designing high-performance, biodegradable packaging materials with integrated multifunctionality. Full article

The rational configuration of electronic band structures through deep-seated structural disorder remains a formidable challenge in sustainable solar-to-fuel conversion. Herein, we report a transformative kinetic strategy to “freeze” an extraordinary density of non-equilibrium structural defects within an integrated Cu₄MgO₅/ZnO nanocomposite. Synthesized via a chitosan-assisted coordination-combustion route followed by rapid thermal quenching, the material preserves a record crystallographic dislocation density of 1.09 × 1015 m⁻² and significant lattice microstrain (1.04 × 10⁻³). This engineered structural disorder induces a profound reconfiguration of the electronic landscape, generating a continuous manifold of sub-bandgap “tail states” that narrow the optical bandgap to a remarkable 1.34 eV. Consequently, the defect-rich architecture facilitates unprecedented dual-channel photocatalytic performance under simulated solar irradiation in an aqueous solution containing 5 vol% triethanolamine (TEOA) as a sacrificial electron donor; the catalyst achieved a hydrogen evolution rate of 17,700.0 µmol g⁻¹ h⁻¹ and a methane production rate of 172.50 µmol g⁻¹ h⁻¹—representing a 36.3-fold and 43.1-fold enhancement over commercial ZnO, respectively. With an apparent quantum yield of 8.42% at 420 nm and robust photostability—maintaining 95.3% of its activity over five consecutive cycles (25 h total)—this noble-metal-free ternary system bypasses the limitations of traditional heterojunctions. Our findings establish a new benchmark for defect-engineered catalysts, providing a scalable blueprint for high-efficiency carbon neutrality and solar fuel production. Full article

In this study, the structural, thermal, and mechanical properties of nanocomposites obtained by adding zinc oxide (ZnO) nanoparticles (NPs), produced by phyto-mediated synthesis using Dianthus chinensis plant extract, to a PMMA-based photopolymer resin at different ratios (0.05%, 0.10%, 0.15%, 0.20%, and 0.25%, by weight) were evaluated. The prepared composite resins were produced in different test geometries using a DLP (digital light processing)-based 3D printer (Asiga Ultra). Following the structural characterization of ZnO nanoparticles, tensile, compressive, and flexural mechanical tests were performed on the resulting composites, as well as FTIR, TGA, DSC, and DMA analyses. The FTIR results showed that ZnO NPs were physically integrated into the matrix. TGA and DSC analyses revealed that the addition of ZnO NPs, particularly at an addition rate of 0.15%, increased thermal stability. DMA analyses showed an increase in storage modulus and glass transition temperature as the addition rate increased. In mechanical tests, the highest modulus of elasticity and maximum strength values were obtained at additive ratios of 0.10–0.15%. The highest tensile strength (55.31 MPa) and compressive strength (388.53 MPa) were obtained at ZnO contents of 0.10–0.15 wt%, while the maximum flexural strength reached 125.94 MPa at 0.15 wt% ZnO. In addition, the storage modulus increased from 1.469 × 10⁹ Pa for the control resin to 1.872 × 10⁹ Pa for the composite containing 0.15 wt% ZnO, indicating improved stiffness and thermomechanical stability. The stress–strain curves show that improvements in ductility and deformation capacity of the material are achieved at these additive ratios. The findings demonstrate that green-synthesized ZnO nanoparticles are an effective and sustainable additive material for improving the mechanical and thermal performance of DLP-based photopolymer dental resins. Full article