Search Results (20,724)

Hybrid material-derived adsorbents have demonstrated exceptional efficacy in a variety of fields, including environmental cleanup and manufacturing operations. In this study, zinc oxide nanoparticles modified with carbon (ZnO-C) as hybrid adsorbent materials were synthesized using both expired zinc chloride and corncob extract. Hybrid ZnO-C adsorbents were employed for the removal of heavy metals, Co(II), and Ni(II) ions, from wastewater via adsorption. Transmission electron microscopy (TEM), scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and energy dispersive spectroscopy (EDS) were among the methods used to fully characterize the structural and morphological properties. To maximize the adsorption process for every metal ion, kinetic and equilibrium studies were carried out. Results revealed that the ZnO-C material formed crystalline, spherical granules with nanoparticle sizes ranging from 25 nm, embedded within a carbon matrix. Additionally, these spherical zinc oxide particles tended to aggregate into clusters. FTIR analysis indicated that the surface of ZnO-C was rich in hydroxyl (OH) groups and zinc oxide, which play a crucial role in the adsorption mechanism. The capacity of ZnO/CC-NPs to adsorb cobalt and nickel ions from aqueous solutions was investigated, examining the influences of initial ion concentration, pH levels, contact duration, and temperature. The findings highlight the high efficiency of ZnO/CC-NPs as an adsorbent, promoting the reuse of waste materials and supporting environmental sustainability efforts. Full article

The increasing demand for sustainable materials in electrical engineering has encouraged the substitution of conventional fillers in epoxy insulation with recycled industrial by-products. This study investigates the potential use of waste tire rubber particles and zinc oxide recovered from electric arc furnace dust as eco-friendly fillers for epoxy resins in high-voltage insulation applications. Four material variants were fabricated: pure epoxy, epoxy with 10 wt% ZnO (0.7 mm thickness), epoxy with 10 wt% tire rubber (0.9 mm thickness), and epoxy with 20 wt% tire rubber (0.9 mm thickness). The breakdown voltage of each composite was measured under AC voltage. Results indicate that filler type and concentration influence breakdown behavior within each thickness group. The 10 wt% ZnO-filled epoxy exhibited a moderate enhancement in breakdown voltage compared with pure epoxy of the same thickness, consistent with interfacial modifications commonly observed in oxide-filled epoxy systems. Conversely, tire rubber fillers led to reduced breakdown performance, likely due to increased dielectric heterogeneity introduced by the elastomeric phase. No direct comparison between ZnO- and rubber-filled systems was performed due to differences in manufacturable sample thickness. The findings contribute to the evaluation of recycled fillers in dielectric composite systems within a circular-economy framework. Full article

This study investigated the application of apricot stone, an agro-industrial by-product, as a sustainable biosorbent for the removal of Zn ions from aqueous solutions and industrial galvanic wastewater. The equilibrium data conformed well to the Sips isotherm model, indicating heterogeneous sorption behavior, and revealed a maximum sorption capacity of 58.2 mg/g. The biosorbent exhibited a high initial removal efficiency of 95% in aqueous Zn solutions, while its performance in real industrial wastewater was reduced to 55%, due to matrix interference. Ecotoxicological test using seed germination assays revealed no phytotoxic effects from the Zn-loaded sorbent. These findings demonstrate that apricot stone is an effective, low-cost, and environmentally friendly sorbent with significant potential for application in Zn-contaminated water treatment systems, contributing to circular economy and waste valorization initiatives. Full article

Growing interest in developing sustainable materials that reduce dependence on fossil resources has led to increased development of bio-based elastomers that can compete with traditional materials in terms of performance when reinforced with additives. This study shows that functionalizing graphene oxide with different alkylamine chains (C8, C12, and C16) enables precise, multidimensional modulation of polymyrcene rubber (PMy) composite behavior. The main finding is that there is a critical concentration of ~1.5–2.0 phr and an optimal chain length of C16 that maximizes mechanical strength, elongation, and toughness simultaneously, thus avoiding the classic trade-off between stiffness and extensibility. Additionally, the study reveals biphasic behavior of graphene oxide modified with dodecylamine (GO_A12) on curing kinetics. At low concentrations, GO_A12 slows vulcanization by competing with accelerators, while at higher concentrations, it accelerates vulcanization via Zn–amine–sulfur complexes. This duality is reflected consistently in the crosslink density, Payne effect, and tensile properties, establishing a coherent structure–property correlation. Identifying an optimal crosslinking regime of ~8.5 × 10⁻⁴ mol/cm³ as the common denominator of the best formulations provides a rational design guide for high-performance elastomers based on renewable matrices and graphene-derived reinforcements. The decrease in tan δ observed through mechanical dynamic analysis suggests potential applications in the tire industry due to increased energy dissipation, which would improve fuel efficiency. Full article

There has been no experimental work on CuCrO₂-ZnSnN₂ heterojunctions (HJs), though theoretical work shows that their photoelectric conversion efficiency is around 20%. Here, CuCrO₂ thin films and p CuCrO₂-n ZnSnN₂ HJs are prepared by varying the sputtering power of the Cu-Cr alloy target while the other parameters are held constant. The as-deposited Cu_xCr_yO_z thin films are amorphous, with CuCrO₂ as the major phase. The CuCrO₂ thin films are p-type conductive, with an optical band gap of about 3.64–3.84 eV. The ZnSnN₂ thin films are wurtzite and n-type conductive. The dark current density J versus voltage V curve measurements show that all the HJs showed rectification, while only the samples deposited at 40 and 50 W had a photo-induced current. Further analysis shows the HJs deposited at 40 W have the lowest shunt conductance, saturation current density, and trap density, implying an effect of fabrication conditions on the properties of HJs. Full article

Cadmium contamination of water resources represents a serious environmental and public health challenge, with conventional treatment methods often proving inadequate for industrial-level remediation. In this study, we present a novel, sustainable composite material, functionalized cellulose nanocrystal polyvinyl alcohol zinc oxide ferric chloride (CNC-PVA-ZnOFe) beads for the efficient removal of cadmium from contaminated water. The material integrates adsorption, coagulation, and flocculation mechanisms within a single hybrid platform, with coagulation–flocculation serving as the dominant mechanism given the material’s macroporous structure and limited surface area (1.2–3.3 m²/g). Functionalized cellulose nanocrystals provide supporting adsorptive sites for metal binding, while a PVA matrix incorporating ZnOFe improves structural integrity, mechanical stability, and coagulation performance. Characterization confirmed successful functionalization, enhanced thermal stability, and a macroporous structure (12–52 nm pores) conducive to floc entrapment, though with limited surface area (1.2–3.3 m²/g) for conventional adsorption. Under optimized conditions (pH 7–10, initial Cd²⁺ concentration of 100 mg/L, coagulant dose of 0.1 g, and sedimentation time of 60 min), the functionalized CNC-PVA-ZnOFe beads achieved a cadmium removal efficiency of 78%, achieving significantly higher cadmium removal efficiency than traditional coagulants, such as aluminum sulfate (69%). The beads also demonstrated good reusability, retaining 85% removal efficiency after five regeneration cycles. This work presents a scalable, eco-friendly material for cadmium removal under controlled laboratory conditions using synthetic solutions. However, further evaluation in real wastewater matrices containing competing ions and organic matter is necessary to establish practical applicability for water treatment applications. The study highlights the combined potential of multifunctional hybrid materials while acknowledging the need for validation under environmentally relevant conditions. While the results indicate successful integration of multiple removal mechanisms, direct validation of synergistic interactions through techniques such as zeta potential and XPS analysis remains an important direction for future research. Full article

Durum wheat (Triticum turgidum L. var. durum) plays a central role in global food and nutritional security, yet its grain mineral and protein quality remain highly variable across varieties and environments. This study aimed to evaluate the combined effects of varieties, nitrogen (N) fertilization, foliar zinc (Zn) and sulfur (S) application, and seasonal variation on grain macro- and micronutrients (Ca, Mg, K, Zn) and protein content, adopting a system-level approach that integrates varieties, nutrient management, and seasonal variability. We hypothesized that aligning variety selection with precision nutrient management would improve grain nutritional quality while enhancing resilience to environmental variation. Significant differences among varieties (p < 0.05) were observed, with the spring-sown variety Durablank exhibiting the highest grain Zn concentration (34.70 mg kg⁻¹) compared with MV Pelsodur (23.0 mg kg⁻¹) and GK Julidur (23.8 mg kg⁻¹), representing a 50.87% varietal difference. Grain Ca, Mg, and K varied widely across varieties and seasons, with drought in 2022 increasing grain Zn, while the wetter 2023 season enhanced Mg and K accumulation. A clear yield–protein trade-off was found, where high-yielding MV Pelsodur maintained 14.3% protein while moderate-yielding Durablank reached 16.8%. Foliar Zn and S applications significantly increased grain Zn, particularly in Zn-efficient varieties. Nitrogen fertilization at 100 kg ha⁻¹ improved macronutrient accumulation by 12–20% compared with 60 kg N ha⁻¹. Significant varieties × N × season interactions (p < 0.01) highlight the need for adjusted varieties -specific nutrient management strategies. Overall, the findings demonstrate that integrating genetic selection with optimized fertilization and season-responsive management practices may contribute to improving grain nutritional quality of durum wheat. Full article

The study investigates the influence of Ca addition (0, 0.5, 0.7, and 1 wt.%) on the microstructure and mechanical properties of friction stir-processed (FSPed) Mg-2.5Si-4Zn-xCa alloys. The microstructures of the processed alloys were characterized using OM, SEM, EBSD, and TEM. The results indicated that Ca addition combined with FSP can synergistically refine and homogenize the Mg₂Si phase, and with increasing Ca content, the size of both primary and eutectic Mg₂Si phases first decreases and then increases, reaching an optimum refinement at 0.7 wt.% Ca. In this composition, the Mg₂Si phases were uniformly dispersed, and the stir zone exhibited significantly refined recrystallized grains compared to its Ca-free counterpart. Under identical FSP conditions, the Mg₂Si phases in the Ca-containing alloys underwent a higher degree of fragmentation. The addition of Ca promoted the formation of the CaMgSi phase by enriching Ca atoms at or near the Mg₂Si phases during FSP, which further assisted in fragmenting the Mg₂Si phases. Consequently, the alloy with 0.7 wt.% Ca demonstrated the best mechanical properties at both room and elevated temperatures, exhibiting tensile strength and elongation of 276.57 MPa and 11.60% at room temperature, 190.13 MPa and 12.17% at 150 °C, and 133.43 MPa and 15.96% at 200 °C, respectively. Full article

Heavy metals in lake sediments represent typical persistent contaminants characterized by recalcitrance, bioaccumulation potential, and delayed toxic effects, thereby exerting sustained adverse impacts on lacustrine ecosystem stability and human health. Liuye Lake is a representative small-to-medium urban lake impacted by ambient domestic sewage discharge and agricultural non-point source pollution, with documented nitrogen and phosphorus enrichment. However, the contamination profile of heavy metals in its surface sediments has not been systematically investigated to date. In this work, surface sediment samples were collected from Liuye Lake, and nine heavy metal elements (As, Cd, Cr, Cu, Hg, Mn, Ni, Pb, Zn) were determined. An integrated approach incorporating Monte Carlo simulation, the geo-accumulation index (I_geo), and the enrichment factor (EF) method was employed to assess the ecological risk and human health risk imposed by these metals. The results revealed the following: (1) Average concentrations of eight heavy metals exceeded the background values of the Dongting Lake water system, with the exception of As, and Hg displayed potential localized anomalies. (2) Surface sediments were collectively categorized as slightly contaminated, with Hg identified as the primary pollutant, followed by minor contamination of Mn, Cr, and Ni; Monte Carlo simulation further suggested a probable risk that Mn contamination could progress to moderate levels. (3) All heavy metals posed low potential ecological risk, with an overall potential ecological risk index (RI) of 62.71, where Cd, Hg, and As were the dominant contributors. (4) Both non-carcinogenic and carcinogenic risks were generally within acceptable limits, whereas children exhibited higher non-carcinogenic susceptibility relative to adults; As and Mn were the leading contributors to non-carcinogenic risk, while Cr and As dominated carcinogenic risk. This study offers a scientific foundation for the prevention and control of heavy metal pollution and the ecological management of urban lakes. Full article

To evaluate the behavior of industrial equipment from a corrosion point of view, it is mandatory to consider both the material that equipment is made from and the working conditions such as temperature, pH, and the existing microorganisms in the working environment. Our studies regarding ecotoxicological monitoring of biological suspensions Diatomee, Saccharomyces, and Spirulina (DSS) are focused on three directions: (1) the evolution of chemical and biological parameters of the reaction environment (pH, conductivity, TDS, DO, OD), the kinetics of DSS microorganisms’ growing curve; (2) the analysis of biofilm forming on the exposed metallic surface and (3) the analysis of corrosion degree (phenomena) of tested metals in five media, by using the corrosion indices: volumetric index, gravimetric index, and penetration index. The viability of microorganisms in the presence of aluminum, zinc, and iron shows the following sequence: Al_Diat > Fe_Diat > Zn_Diat > Al_Spir > Zn_Spir > Al_Sach > Zn_Sach > Fe_Spir > Fe_Sach. The development of biofilms on the surface of metal plates followed the sequence outlined below: Al_Diat > Fe_Diat > Zn_Diat > Fe_Spir > Zn_Sach > Fe_Sach > Al_Sach > Zn_Spir > Al_Spir. Iron exhibits the most favorable performance, displaying a very low Ip value across all tested environments, including salt water. Aluminum demonstrates sensitivity to specific biological environments, with the highest degree of corrosion observed in Spirulina, indicating that not all biological environments confer protection to aluminum. Diatoms and Saccharomyces suspensions exert an inhibitory effect on corrosion. Zinc is the most susceptible metal, experiencing the greatest corrosion in Spirulina, followed by salt water, while biological environments only partially mitigate the corrosion rate. Full article

Hybrid nanomaterials integrating magnetic and semiconductor phases offer promising multifunctional platforms for wastewater remediation; however, their stabilization and recovery remain challenging. In this study, Fe₃O₄ and ZnTiO₃/TiO₂ nanoparticles were incorporated into a rice husk ash-based geopolymer matrix to develop hybrid nanocomposites for synergistic adsorption–photodegradation of methylene blue (MB) and methyl orange (MO). The materials were synthesized via alkaline activation followed by nanoparticle incorporation, and characterized by XRD, XRF, FTIR, SEM, EDX, BET surface area analysis, and pHPZC determination. XRD confirmed the presence of nanocrystalline Fe₃O₄ and ZnTiO₃/TiO₂ phases while preserving the amorphous aluminosilicate framework. Modified powders exhibited higher specific surface areas (up to 198 m² g⁻¹) compared to the unmodified geopolymer. Adsorption followed the Langmuir isotherm and pseudo-second-order kinetics, with spontaneous and exothermic behavior. Under UV irradiation, the ZnTiO₃/TiO₂-modified composite achieved photodegradation efficiencies up to 94% for MB and 92% for MO, whereas the Fe₃O₄-modified material combined adsorption capacity with magnetic recoverability. These results demonstrate that nanoparticle incorporation enables multifunctional performance while maintaining structural integrity of the geopolymeric matrix. Full article

Stainless steel (SS) remains widely used in orthopedic implants but is susceptible to corrosion and implant-associated infections in physiological environments. This study aimed to develop a multifunctional multilayer coating combining corrosion resistance, bioactivity, and antimicrobial performance. A ZnO base layer was deposited on 316L SS via pulsed laser deposition, followed by matrix-assisted pulsed laser evaporation of a lovastatin-functionalized bioactive glass (BG57 + LOV) top layer. Two LOV concentrations were initially evaluated, and BG57+0.1LOV was selected based on structural homogeneity, cytocompatibility, and antimicrobial balance. Physicochemical characterization confirmed preservation of chemical integrity and formation of continuous, moderately rough coatings. Electrochemical impedance spectroscopy in simulated body fluid demonstrated progressive improvement in corrosion resistance from bare SS to ZnO-coated and finally to the BG57+0.1LOV/ZnO multilayer, which exhibited the most electropositive corrosion potential and effective suppression of charge-transfer reactions. Biological assays revealed high viability of osteoblasts, fibroblasts, keratinocytes, and macrophages without significant oxidative or nitrosative stress. Antimicrobial testing showed strain-dependent activity, with enhanced efficacy against MRSA and significant reduction in P. aeruginosa, associated with increased ROS/RNS generation. Overall, the BG57+0.1LOV/ZnO system represents a promising multifunctional coating strategy for corrosion-resistant and infection-resistant SS implants. Full article

The surrounding soil in mining areas generally suffers from severe pollution, characterized primarily by multi-metal contamination, and poses significant challenges in restoration and safe utilization. Therefore, it is urgent to explore low-cost restoration and safe utilization technologies that can achieve simultaneous treatment and utilization. This study selected a typical lead-zinc mining area in eastern Yunnan, China, where there is severe heavy metal pollution. It collected 15 common varieties of castor plants and systematically studied their absorption, accumulation, translocation, and removal characteristics of four heavy metal elements (Cd, Pb, Cu, Zn). The results showed that the heavy metal pollution in the mining area was extremely severe. Castor plants have a strong tolerance to heavy metal stress. There were significant differences in the absorption and accumulation of heavy metals among different castor varieties. The root parts mainly accumulated Pb, the stem parts mainly accumulated Cd, and the seeds had a higher ability to accumulate Cu. In terms of restoration potential, the Tong Castor No. 24, Fen Castor No. 10, and Zi Castor No. 3 plants had relatively large restoration potential. However, considering both biomass and heavy metal removal capacity, Dian Castor No, 2 Zi Castor No. 3, Dian Castor No. 5 plants were more ideal and could be applied in the restoration of heavy metal complex pollution soil in mining areas. Full article

Zinc-based coatings are insufficient as surface coatings; they corrode rapidly and can cause long-term damage to subsea pipelines and other instruments. Therefore, this research was undertaken by manufacturing a sacrificial nano-reinforced Zn coating combined with additives via electrodeposition onto a mild steel S235 substrate, which provides excellent corrosion resistance under severe marine conditions. The electrodeposited coatings were characterized using SEM/EDS and XRD, revealing the effective incorporation of cerium oxide nanoparticles and high-quality graphene (Gr) in the zinc matrix. Vickers microhardness measurements, mechanical resilience, and surface roughness of the Zn-CeO₂-Gr coating showed an inverse correlation between improved microhardness (+65.85%) and mechanical resilience (+31.49%), while surface roughness decreased (−81.48%) compared to pure zinc electrodeposited coatings. These characteristics indicate grain refinement and greater reliability under mechanical stress. Electrochemical impedance spectroscopy (EIS) and DC polarization measurements indicate a significant improvement in corrosion resistance compared to pure zinc, due to the synergistic effect between graphene and cerium oxide nanoparticles, which reduces the cathodic activity of the surface. These findings offer promising applications for cutting-edge materials in saline environments. Full article

Cu₂ZnSn(S,Se)₄ (CZTSSe) is a candidate thin-film photovoltaic material; however, its performance is restricted by innate defect-induced nonradiative recombination. Low-concentration Ge doping has been identified as an efficient way to mitigate these defects, but the selenization temperature remains an important process parameter that governs the structure and optoelectronic characteristics of CZTSSe absorbers. In the present work, low-concentration Ge-doped Cu₂ZnSn_0.95Ge_0.05S₄ (CZTGS) precursor films were synthesized through a green, n-butylammonium butyrate-based solution approach. The effects of the selenization temperature (530–570 °C) on the microstructure, composition, and photovoltaic performance of Cu₂ZnSn_0.95Ge_0.05(S,Se)₄ (CZTGSSe) films and devices were comprehensively investigated. X-ray diffraction (XRD), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), energy-dispersive X-ray spectrometer (EDS), atomic force microscopy (AFM) were performed to comprehensively characterize the synthesized samples, and the results suggested that the selenization temperature dramatically altered the film grain growth, crystallinity, elemental retention and surface roughness. Specifically, the film that underwent selenization at 550 °C presented the best crystallinity, which was accompanied by large-scale even grains, efficient Ge⁴⁺ addition to the kesterite lattice and the lowest surface roughness. These better properties in terms of structure and composition resulted in the lowest carrier transport resistance (R_s = 8.6 Ω∙cm²), improved recombination resistance (R_j = 5.9 kΩ∙cm²), inhibited nonradiative recombination, and prolonged carrier lifetime (τ_EIS = 35.8 μs). Therefore, the resulting CZTGSSe thin-film solar cell had an 8.69% better power conversion efficiency (PCE), while its open-circuit voltage (V_OC) was 0.42 V, the fill factor (FF) was 55.51%, and the short-circuit current density (J_SC) was 37.71 mA·cm⁻². Our results elucidate the mechanism by which the selenization temperature regulates low-concentration Ge-doped kesterite devices and provide more insights into the optimization of processes for cost-effective, high-performance, and green thin-film solar cells. Full article