Search Results (756)

Benzaldehyde is a key intermediate in the fine chemical, pharmaceutical, fragrance, and agrochemical industries, and the development of efficient and sustainable synthetic routes remains a major research priority. This review critically examines the principal catalytic pathways reported for benzaldehyde production, with particular emphasis on the oxidation of benzyl alcohol and the partial oxidation of toluene. Reaction conditions, catalytic systems, and performance descriptors such as conversion and selectivity are systematically analyzed, highlighting the strengths and limitations of each approach. Special attention is given to the choice of oxidants, reaction phase, and operating temperature, as these factors strongly influence process efficiency and product distribution. From a sustainability perspective, conventional routes are compared with greener alternatives based on molecular oxygen or air, aiming to reduce energy consumption and the generation of hazardous by-products. The review further discusses current challenges associated with catalyst stability, overoxidation, and process scalability. It identifies the principal scientific gaps limiting the industrial implementation of heterogeneous catalytic systems and critically examines how catalyst design, synthesis methodologies, sustainable feedstocks, waste-derived materials, and techno-economic considerations can collectively contribute to scalable and environmentally responsible benzaldehyde production. Finally, future research directions are proposed to guide the development of highly selective, economically viable, and sustainable catalytic processes. Full article

The widespread use of neonicotinoids (NEOs) poses a significant risk to school-aged children. However, critical knowledge gaps remain regarding their comprehensive exposure profiles and associated health risks. This study assessed the co-exposure levels and non-carcinogenic risks of 16 NEOs (including both traditional and emerging compounds) in 184 school-aged children recruited from a typical rural and urban area of South China. The sum concentrations of 16 NEOs (∑₁₆NEOs) ranged from 0.648 to 227 μg/L (median: 8.99 μg/L). The predominant compounds were clothianidin (CLO, 1.93 μg/L), N-desmethyl-acetamiprid (N-dm-ACE, 1.64 μg/L), thiamethoxam (THM, 0.792 μg/L), and dinotefuran (DIN, 0.222 μg/L). To our knowledge, this is the first report of emerging NEOs—paichongding (IPP), sulfoxaflor (SUL), and flonicamid (FLO)—in children urine, with detection frequencies of 11.4%, 68.2%, and 53.4%, respectively. Significant rural–urban disparities in urinary concentrations were observed. The metabolite-to-parent ratios (e.g., N-dm-ACE/ACE, 5-OH-IMI/IMI, and THCP-AM/THCP) may serve as a useful biomarker for assessing human exposure to NEOs, as it provides valuable insight into the metabolic fate of the target compounds and aids in distinguishing exposure pathways. The median estimated daily intake (EDI) values for CLO, N-dm-ACE, THM, and ∑₁₂NEOs were 0.127, 0.117, 0.046, and 0.696 μg/kg-bw/day, respectively. Although the hazard quotient for individual compounds was below 1 for vast majority of school-aged children, cumulative exposure assessment indicated that 1.09% of participants had a hazard quotient exceeding 1 for both IMI_eq and ∑₁₂NEOs, suggesting potential health concerns under co-exposure scenarios. Using a multi-criteria Toxicological Priority Index (ToxPi) model, CLO, THM, thiacloprid-amid (THCP-AM), and N-dm-ACE were identified as the high-priority compounds requiring regulatory attention in children’s environmental health. This study provides the first comprehensive biomonitoring and ToxPi-based prioritization of both traditional and emerging NEOs in school-aged children in South China. The findings highlight the urgent need for continued monitoring, refined mixture risk assessment, and regulatory consideration of emerging substitutes and their metabolites, which are not adequately covered by current safety guidelines. Full article

Aerobic composting converts agricultural waste into stable, humus-rich products, and the application of exogenous additives is an efficient strategy to enhance humification. This systematic review synthesized studies published between 2023 and 2026 on additives that promote humification during agricultural waste composting. Based on the distribution of the retrieved literature, additives are categorized into inorganic additives, organic additives, biological strategies, and composite systems, and the effects and mechanisms of each category are systematically discussed. Iron-based additives achieve the highest humic acid (HA) increases of 82–267% through Fenton-like redox catalysis. Clay minerals and biochar produce moderate HA enhancements of 25–163% via physical structuring and surface adsorption with broader applicability. Small-molecule precursors and exogenous humic substances achieve HA gains exceeding 100% at sub-percent doses. Biological strategies provide self-sustaining catalytic activity but are sensitive to environmental conditions. Composite additives, the largest category, generally outperform single additives through functional complementarity, though antagonistic effects have also been documented. Cross-study patterns suggest that different feedstocks respond preferentially to distinct additive types, though systematic experimental validation is lacking. Critical gaps between laboratory findings and practical application are identified, including the predominance of small-scale studies, the absence of techno-economic analysis, and the unassessed environmental fate of metal-based additives. Future research priorities include pilot-scale validation under industrial conditions, the establishment of standardized humification metrics, and long-term field monitoring. Full article

In this work, nanocrystalline high-entropy spinels with the nominal composition (Co,Mn,Ni,Cr,Fe)₃O₄ and different Fe contents were synthesized by a facile solution combustion method and evaluated as catalysts for the complete oxidation of light hydrocarbons and methanol decomposition. Structural characterization by XRD, SEM, TEM, XPS, Mössbauer spectroscopy, and N₂ physisorption confirmed the formation of single-phase cubic spinels and mesoporous morphology. Increasing the Fe content resulted in changes in surface elemental distribution without altering the oxidation states of the cations. Among the investigated catalysts, HES-Fe 1:1 exhibited the highest specific surface area, favorable surface enrichment in Co and Mn, and the best catalytic performance for the complete oxidation of light hydrocarbons. In methanol decomposition, HES-Fe 1:1 showed the highest methanol conversion at lower temperatures, whereas HES-Fe 1:2 exhibited the highest CO selectivity, making it the most efficient catalyst for syngas production. The results establish a relationship between Fe content, surface composition, redox properties, and catalytic performance, revealing high-entropy spinels as promising catalysts for environmental catalysis and syngas production. Full article

Biochar is a porous carbonaceous material synthesized through the pyrolysis of diverse biomass resources, including agricultural and forestry residues as well as livestock manure. It possesses superior characteristics such as a large specific surface area, adjustable pore architecture, abundant surface functional groups, and favorable electrical conductivity. With the increasingly severe global energy shortage and environmental pollution problems in recent years, biochar has emerged as a green, low-cost functional material with distinct application superiority in multiple key research directions, including energy storage and conversion, chemical catalysis, environmental restoration, and signal sensing and detection. This study comprehensively summarizes the latest research advances of biochar in the aforementioned application fields, focusing on innovative achievements in photocatalytic and electrocatalytic hydrogen generation, supercapacitors and electrochemical energy storage systems, persulfate activation technology, carbon dioxide capture, remediation of heavy metal and organic contaminants, volatile organic compound (VOC) adsorption, as well as electrochemical sensing devices. Existing research results demonstrate that modification strategies including metal and non-metal doping, surface oxidation treatment, and compounding with semiconductors or metal oxide materials can effectively improve the catalytic activity and functional performance of biochar. Furthermore, this paper prospects the future interdisciplinary development trends of biochar, analyzes the existing research gaps in mechanism exploration, structural optimization design, and industrial large-scale preparation, and provides theoretical and practical references for the further popularization and application of biochar in sustainable energy development and environmental governance fields. Full article

Solar-driven interfacial evaporation (SDIE) represents a highly promising technology for decentralized desalination and wastewater treatment, yet its practical industrial deployment is severely constrained by the intrinsic intermittency of natural solar irradiance and nocturnal salt crystallization. To smooth energy fluctuations and achieve all-weather, continuous freshwater output, integrating solid–liquid phase change materials (SLPCMs) into SDIE has evolved into a system-level paradigm shift driven by advanced spatiotemporal thermal-mass management. This review systematically summarizes recent breakthroughs in micro-to-macro structural engineering for phase-change-coupled SDIE systems. Spatially, advanced microscopic encapsulation strategies such as 3D matrices, core–shell architectures, and solid–solid transitions eradicate molten PCM leakage and reconstruct heat transfer networks, while macroscopic configurations involving sandwich structures and 3D directional channels realize functional zoning to maximize thermal localization. Temporally, the controlled nocturnal release of stored latent heat establishes a cross-timeline energy relay, sustaining dark evaporation and activating interfacial hydrodynamics via Marangoni convection and thermophoretic diffusion to prevent salt clogging under extreme conditions. Furthermore, cross-disciplinary integrations for water-electricity co-generation, targeted resource recovery, and environmental remediation are comprehensively discussed. Finally, critical engineering challenges regarding scalability, cost-effectiveness, and condensation system integration are addressed, offering forward-looking perspectives on coupling thermal storage with physical catalysis to transcend classical thermodynamic limits. Full article

The global energy transition and rapid electrification are driving increased demand for copper. However, conventional pyrometallurgical and hydrometallurgical extraction routes are increasingly challenged by declining ore grades and stricter environmental regulations. Bioleaching involves the microbial catalysis of sulfide mineral dissolution and provides a sustainable method for copper recovery from low-grade ores, tailings and secondary resources. This review provides a critical and integrated analysis of copper sulfide bioleaching, covering microbial diversity, molecular mechanisms, mineralogical controls, operational parameters, and industrial applications. This review also examines the functional roles of prominent acidophiles, including the functional roles of prominent acidophiles, including Acidithiobacillus spp., Leptospirillum spp. and thermophilic archaea, in the oxidation of iron and sulfur, mitigation of passivation, and metal solubilization. The molecular underpinnings of these processes are explored by investigating iron and sulfur oxidation gene networks (the rus operon and sox cluster), copper resistance systems (CopA, CusCBA) and biofilm formation pathways. The mineralogical controls on the behavior of chalcopyrite (refractory/passivating), chalcocite (highly reactive) and bornite (intermediate) are critically assessed. The synergistic effects of key operational parameters (temperature, pH, redox potential, aeration and particle size) on leaching kinetics and microbial community dynamics are investigated. The scalability, efficiency and environmental footprint of industrial applications such as heap, dump, stirred-tank and in situ bioleaching are discussed. Despite more than four decades of commercial development, several challenges remain, such as slow chalcopyrite dissolution, passivation, metal toxicity, and scale-up limitations. Emerging solutions such as synthetic microbial consortia, multi-omics technologies, artificial intelligence-assisted optimization, and digital twins are identified as transformative approaches for next-generation biomining. In this review, microbiology, mineralogy, electrochemistry, and process engineering are integrated to demonstrate that biotechnological leaching is among the most promising technologies for the sustainable production of copper and to identify future directions for its industrial application. Full article

Steam gasification of woody waste represents a sustainable pathway for addressing environmental issues with energy recovery. However, challenges such as low hydrogen content and high tar yield severely limit the gasification efficiency and hinder its large-scale application. In this study, a composite Ni/CaO catalyst was developed to enhance the yield of H₂-rich syngas in woody waste gasification, with Ni loading serving as the active site for catalytic cracking and CaO support as the CO₂ sorbent for sorption-enhancement. Ni nanoparticles ranging from 18 to 28 nm in diameter are uniformly distributed on the CaO support. At 700 °C, Ni/CaO with 10 wt.% Ni loading enables the 455.4 mL/g H₂ yield with an H₂/CO ratio of 1.93, representing increases of 137% and 230%, respectively, compared to non-catalytic conditions. Meanwhile, the tar yield was 12.1 wt.% with an aromatics selectivity of 37%, corresponding to reductions of 50.2% and 54%, respectively. Characterizations confirmed that Ni particles were uniformly distributed on the support in the form of metallic Ni. The Ni active sites promote syngas production by facilitating the cleavage of C-C and C-H bonds in volatiles, while the CaO support enhances H₂ generation by shifting the water–gas shift reaction equilibrium forward. This study provides a promising strategy for enhancing hydrogen-rich syngas production from woody waste gasification. Full article

MXene composites represent an exceptionally promising member of the family of two-dimensional multifunctional materials known for outstanding electrical properties, mechanical strength, chemical tuning abilities, and the potential for wide applications. The paper conducts a profound patent landscape investigation of MXene composites with the help of the WIPO PATENTSCOPE database. In total, 658 patent families were found; duplicate patent entries were eliminated through the application of the Single Family Member method. The results show that China is a patent leader worldwide, followed by PCT applications and the patenting activity of the USA, India, and other countries, which indicates a growing international interest in MXene technologies and materials. The classification of patents also shows that this technology is actively researched in relation to the development of technologies in the field of electrochemical energy storage, polymer engineering, sensing technologies, catalysis, environmental remediation, electronics, and biomedical applications. Additionally, the paper studies the technology development in the field of the creation of MXene antennas, semiconductor devices, and ceramic oxide composites, materials that change shape, anti-corrosion coatings, electrochemical sensors, and many others. Even though substantial advances have been made, obstacles related to efficient manufacturing, oxidation resistance, quality assurance, sustainability, and industry adoption persist. The overall picture of patents shows that MXene-based composite materials have progressed from the testing stage to commercial products with high potential for next-generation technologies. Full article

The high color intensity, chemical stability, and toxic persistence of textile dye wastewater form a serious environmental problem. In this work, the degradation of methylene blue (MB) using a high-voltage discharge plasma (HVDP) system has been studied, with a focus on plasma–catalyst interactions. A high-voltage DC surface-discharge reactor with a point-to-plane electrode configuration was used. The positive electrode was placed in the air, and the negative electrode was placed in the dye solution. A DC voltage was applied to generate plasma discharge at the air–liquid interface. The influence of solution pH and conductivity, as well as the use of a magnetite (Fe₃O₄) catalyst, were systematically studied. These discharges generate a strong electric field, thereby contributing to the dye decomposition. Plasma propagation and degradation efficiency were significantly improved under the acidic conditions (pH 3). As the solution conductivity increased, the current flow also increased, but plasma chemical activity of streamer discharge decreased at higher conductivity levels. Incorporation of a magnetite catalyst led to a further enhanced decolorization performance by amplifying local electric fields and surface interactions. The highest color removal efficiency of 98.14% was obtained at optimized conditions, i.e., pH of 3, Fe₃O₄ dosage of 7.5 g/L, and DC voltage of 15.9 kV after 60 min. Results show that plasma-assisted degradation with magnetite catalysis is an efficient and sustainable method for treating dye-contaminated wastewater. Operational parameters, such as pH, conductivity, and catalyst use, should be optimized to maximize treatment efficiency. Full article

Precious metal nanoparticles (PMNPs), particularly silver, gold, palladium, and platinum nanoparticles, have attracted considerable attention owing to their unique physicochemical properties and broad applications in catalysis, environmental remediation, and biomedicine. Conventional physical and chemical synthesis methods often require substantial energy input, harsh reaction conditions, and generate large volumes of metal-containing wastewater, raising concerns regarding sustainability and environmental impact. Microbial synthesis provides a sustainable alternative by using microorganisms as natural biofactories to convert toxic precious metal ions into valuable nanoparticles under mild conditions. This review summarizes recent advances in the microbial synthesis of PMNPs (Bio-PMNPs), focusing on biosynthetic mechanisms in bacteria, algae, and fungi. Bio-PMNPs formation involves both extracellular and intracellular reduction processes, coupled with electron transfer mediated by reductases and other redox-active biomolecules. Functional groups present on microbial cell walls, as well as proteins, polysaccharides, enzymes, and other metabolites, play important roles in the adsorption, reduction, stabilization, and growth of nanoparticles. We further highlight the applications of Bio-PMNPs in antimicrobial activity, cancer therapy, pollutant degradation, heavy-metal removal, and catalytic enhancement of organic synthesis. Despite substantial progress, challenges remain in controlling nanoparticle size and morphology, elucidating biosynthetic mechanisms, and achieving large-scale production. Future integration of synthetic biology, metabolic engineering, and process optimization is expected to improve the controllability, stability, scalability, and biosafety of Bio-PMNPs production. Full article

As naturally occurring bioactive molecules derived from plants, polyphenols exhibit significant potential for the functional modification and structural regulation of metal–organic frameworks (MOFs) due to their unique ortho-phenolic hydroxyl groups, excellent metal-coordinating ability, and favorable biocompatibility. This review systematically summarizes the functional roles of polyphenols in MOF systems, including their use as organic ligands to directly participate in framework construction, as surface modifiers to optimize MOF interfacial properties, or as encapsulation hosts to enable controlled loading and release. Polyphenol–MOF composites constructed based on these strategies demonstrate broad application prospects in fields such as biomedicine, food science, environmental remediation, and catalysis. This paper further analyzes the key challenges currently facing the research community, including unclear mechanisms of interfacial interactions, insufficient stability assessments under complex conditions, and a lack of scalable green synthesis processes. Future research should delve deeper into the relationship between polyphenol structures and MOF topological configurations and drive the transition from functional composites to functional synergies. These efforts will be key to realizing the practical application of such materials in intelligent food manufacturing, precision medicine, and sustainable environmental management. Full article

MXenes have emerged as a rapidly expanding family of two-dimensional transition-metal carbides, nitrides, and carbonitrides, characterized by exceptional compositional diversity, tunable surface chemistry, metallic conductivity, hydrophilicity, mechanical flexibility, and rich redox activity. These characteristics make MXenes highly attractive for next-generation technologies, including energy storage and conversion, catalysis, electromagnetic interference shielding, sensors, water purification, biomedical systems, and smart functional devices. However, the performance of MXene-based materials is strongly governed by their synthesis routes, defect structures, interlayer spacing, surface terminations, oxidation stability, and interfacial interactions with polymers, metals, oxides, and other two-dimensional materials. Therefore, a structure–property-oriented understanding is essential for moving MXene research from empirical material development toward rational functional design. Unlike application-centered summaries, this review develops a cross-application engineering framework that connects MXene synthesis and processing with multiscale structure, functional properties, performance trade-offs, and translational requirements. First, major synthesis and processing strategies are discussed, including selective etching, delamination, intercalation, surface modification, and scalable fabrication. Next, the relationships between MXene composition, morphology, surface chemistry, electrical conductivity, electrochemical behavior, mechanical properties, and environmental stability are analyzed. Recent advances in functionalization, heterostructure construction, and composite engineering are then highlighted to illustrate how MXene properties can be tailored for emerging applications. Finally, key challenges related to oxidation, restacking, long-term stability, environmental safety, reproducibility, and industrial translation are critically evaluated. This review aims to establish a design framework for engineering MXene nanomaterials toward high-performance, stable, and scalable emerging technologies. Full article

Polydimethylsiloxane (PDMS) is a promising material for the fabrication of 3D scaffolds, thanks to its versatility and the possibility of producing sponge-like architectures through sugar-templating methods. The incorporation of functional additives further expands their potential, extending the applicability of PDMS-based systems toward advanced functional systems in areas such as environmental remediation, sensing, and biomedicine. Among these additives, metal-based nanomaterials such as layered double hydroxides (LDH) are particularly attractive due to their tuneable composition and multifunctional properties. LDHs have gained increasing attention in a range of fields, including biomedical and environmental research, thanks to their biocompatibility, controlled intercalated species release, catalysis, and sensing potential. Previous studies have incorporated LDHs into PDMS sponges via post-synthesis impregnation of pre-formed LDH crystallites, typically synthesized by co-precipitation. While widely used, co-precipitation may limit control over LDH crystallinity, morphology, and structure, affecting performance. In contrast, in situ growth strategies enable more controlled nucleation and development of the LDH structure, leading to improved structural definition and physicochemical properties. In this study, we propose a simple and cost-effective approach based on the incorporation of LDH synthesized under controlled in situ conditions into a porous PDMS sponge matrix with various architectures developed through the use of different sugar templates, enabling tuneable pore sizes while maintaining a scalable and accessible fabrication process. Full article