ChemSusChem最新文献

Developing sustainable routes to biodegradable polymers from renewable feedstocks is key to reducing reliance on petroleum and mitigating environmental pollution. Amino acids, such as L-alanine, are valuable monomers for biodegradable nylons. Artificial photosynthesis has recently been applied to amino acid synthesis, yet the use of biomass-derived nitrogen sources such as urea in visible-light driven L-alanine synthesis has not yet been explored. Here, we present a novel artificial photosynthetic system that converts urea and pyruvate, both biomass-derived compounds, into L-alanine under visible light. In this system, a visible light-driven NADH regeneration system consisting of triethanolamine (TEOA), zinc meso-tetra(4-sulfonatophenyl)porphyrin tetrasodium salt (ZnTPPS^4-), and pentamethylcyclopentadienyl (Cp*) rhodium 2,2'-bipyridine (bpy) ([Cp*Rh(bpy)(H₂O)]²⁺) is integrated with urease (URE), hydrolyzes urea into ammonia, and L-alanine dehydrogenase (AlDH), catalyzes the reductive amination of pyruvate. Under irradiation, the system produced 0.85 mM L-alanine after 24 h (85% yield based on pyruvate). This work represents the first exploration of urea-based, visible-light powered enzymatic L-alanine synthesis, offering a sustainable route to biodegradable polymer precursors from renewable nitrogen and carbon sources.

This study explores the impact of (i) different installation modes of the molecular rhenium catalyst Re within the PCN-777 metal-organic framework (MOF) and (ii) catalyst loading on the resulting catalytic performance and recyclability of the different hybrid materials in the photocatalytic reduction of CO₂ to CO. Through systematic investigation, we demonstrate that a robust coordination linkage between a zirconium node of the framework and the catalyst, obtained via solvent-assisted ligand incorporation (SALI), minimizes rhenium leaching. In contrast, physical entrapment and electrostatic anchoring methods result in significant rhenium leaching after installation. Additionally, we reveal how the installation mode influences the electronic properties of the catalyst, which allows us to tune the catalytic activity. Furthermore, based on these results, we determine the optimal loading and concentration of Re within the MOF matrix for photocatalytic CO₂ reduction.

Electrocatalytic nitrate reduction reaction (NO₃ ^-RR) offers a sustainable and energy-efficient alternative for green ammonia synthesis, with the added benefit of environmental remediation and resource recovery. In recent years, it has attracted significant attention. However, the challenges of achieving high selectivity and maintaining catalyst stability have substantially restricted its practical applications. To address these issues, researchers have proposed a variety of catalytic regulation strategies aimed at enhancing catalyst activity and product selectivity. This review systematically summarizes recent advances in catalyst design for NO₃ ^-RR from the perspectives of composition regulation, structural engineering, and support strategies. We highlight the underlying mechanisms and performance features of each strategy, emphasizing their roles in modulating electronic structure, constructing efficient active sites, and optimizing interfacial environments. In addition, we discuss the potential of integrating multiple strategies and deepening the understanding of structure-activity relationships. Finally, we outline future directions and key challenges for developing efficient, stable, and scalable NO₃ ^-RR catalytic systems, offering insights to guide continued progress in this emerging field.

With the rising demand for sustainable materials, lignin-based polyols offer a promising renewable alternative to traditional petroleum-based polyols in flexible polyurethane (PU) foams. This study focuses on synthesizing novel high-performance lignin-based polycarbonate polyols via transesterification with dimethyl carbonate. The resulting lignin polyols exhibited hydroxyl values ranging from 111 to 179 mg KOH/g and viscosities of 12,000-26,000 mPa·s, thereby enhancing the suitability of lignin for flexible foam formulation. An in-depth structural analysis using proton, carbon, phosphorus, and 2D nuclear magnetic resonance confirmed the grafting of long polyether chains and the introduction of multiple carbonate linkages onto the lignin structure. Foams were formulated by replacing up to 60% of petroleum-based polyols with either synthesized lignin polyol or a mixture of lignin and soy polyols. Formulated foams demonstrated superior mechanical properties, including enhanced tensile strength and load-bearing capacity, compared to petroleum-based foams. Additionally, the developed foams with biobased polyols exhibited improved thermal stability, shock absorption, and partial biodegradability.

Rechargeable zinc-iodine batteries (RZIBs) have garnered significant attention owing to their distinct superiorities of low cost, high safety, and high theoretical capacity. However, their large-scale implementation is hindered by several critical challenges, including the polyiodide shuttle effect, uncontrolled Zn dendrite growth, interfacial corrosion issues, and pronounced self-discharge. This review systematically summarizes hydrogel electrolyte-based strategies, with the objectives of suppressing the polyiodide shuttle effect, promoting uniform Zn deposition, enhancing environmental adaptability, facilitating multi-electron iodide conversion, and enabling flexible applications. These efforts are expected to advance the development of high-performance, long-lifespan RZIBs toward practical utilization.

Constructing efficient charge separation pathways remains a critical challenge for enhancing photocatalytic hydrogen evolution performance. In this study, a cobalt doping strategy was employed to precisely modulate the band structure of NiO, leading to the formation of an S-scheme GDY/Co_0.10Ni_0.90O heterojunction. UV-Vis diffuse reflectance spectroscopy and Mott-Schottky analyses confirmed that cobalt doping not only broadens the light absorption range but, more importantly, induces a fundamental transition of the heterojunction type from Type-I (GDY/NiO) to S-scheme (GDY/Co_0.10Ni_0.90O). The optimized CGCN35 sample achieves a hydrogen evolution rate of 2.03 mmol/g/h, which is 10 times higher than that of pristine NiO. In situ X-ray photoelectron spectroscopy, density functional theory calculations, electron paramagnetic resonance testing, and Kelvin Probe Force Microscopy further reveal the built-in electric field and band bending characteristics at the S-scheme heterojunction interface. This elucidates the synergistic mechanism that promotes spatial charge separation while preserving strong redox capabilities. This work demonstrates that precise doping engineering enables the controllable modulation of heterojunction band alignment, offering a new strategy to overcome the trade-off between charge separation and redox capability in conventional heterojunctions, thereby providing both theoretical foundation and practical paradigm for designing highly efficient photocatalysts.

Hard carbon has recently attracted significant attention as a promising anode material for sodium-ion batteries (SIBs) due to its high structural stability and appreciable discharge capacity arising from pore filling of Na⁺. In this work, we synthesized hard carbon by carbonizing waste polymers from waste carbon fiber reinforced plastic. During the carbonization process, the heating rate was carefully controlled to exploit the gas bubbles released from the water retained in the polymers, thereby generating a porous hard carbon. The resulting porous hard carbon was subsequently employed as the anode material for SIBs. Taking advantage of the porous architecture, high-rate electrochemical testing was performed. Notably, the sample heat-treated at 1600°C exhibited a reversible capacity of 112.4 mAh g^-1 after 700 cycles at 1 A g^-1 and maintained as high as 59.1 mAh g^-1 even after 7000 cycles at 2 A g^-1, underscoring its remarkable long-term cycling stability.

Xylose acetalization has emerged as a potent tool to extract this sugar from lignocellulosic biomass and for creating new biobased chemicals and materials. This article elucidates a generalized reaction network for xylose acetalization and reveals the role of aldehyde electrophilicity and ring strain in intermediate formation. Aldehydes with strong electrophilicity stabilize xylose as both furanose- and pyranose-monoacetals, whereas weaker aldehydes favour xylofuranose acetalization due to the high ring strain in pyranose acetals. The energetically favoured furanose diacetals dominate the product distribution over extended reaction time regardless of aldehyde types and reaction pathways. Measurements of the xylose tautomer ratio in the reaction conditions highlighted the importance of xylose isomerization in forming furanose acetals. These mechanistic insights not only explain the evolution of reaction intermediates but also aid in identifying potential products for sustainable chemical synthesis.

Growing environmental awareness has led to a shift in focus toward green chemistry and the development of more sustainable materials. Cellulose is one of the most abundant renewable polymers, providing stability and flexibility in plant cell walls. Because of these properties, it has often been used as a base material for textiles, which can be recycled and the cellulose recovered, making it a promising candidate for environmentally friendlier polymer synthesis. Herein, we show a sustainable method for recycling and modifying cellulose to facilitate photochemical crosslinking to attain biocompatible hydrogels under mild reaction conditions, which can thus also be used for the fabrication of complex 3D structures via digital light processing (DLP). This approach presents an excellent technique for the fabrication of customized cell scaffolds for biomedical applications, such as the use as a wound dressing to treat chronic wounds.

Furfural is a promising renewable platform chemical derived from biomass. Its electrochemical conversion offers the opportunity for considerable sustainability gains, i.e., by using a combination of a renewable feedstock and renewable energy. To widen the range of products available by electrochemical conversion/derivatization, indirect electrolysis (using a redox-active mediator), is a viable way. Existing methods for indirect electrolysis of furfural have been developed for divided cells only, requiring specific membranes that increase complexity and costs. Here, we describe a convenient indirect electrochemical method of furfural oxidation in an undivided cell. In this approach, HOBr is produced in situ from bromide salt and subsequently used as an oxidant in Baeyer–Villiger-type oxidation. The initially produced product, 2(3H)-furanone, immediately hydrolyzes into succinic semialdehyde. During extraction with an organic solvent, it converts back and could be isolated from the aqueous reaction mixture in the form of 2(3H)-furanone, an unstable compound. Finally, it is isomerized into the more stable 2(5H)-furanone isomer in 48% yield. The developed method represents a simple and convenient electrochemical tool for the synthesis of a renewable furanone-based building block in an undivided cell with yields comparable to existing thermochemical methods and allows to use (renewable) electricity as a driving force.