Green Chemistry最新文献

Electrochemical conversion of organic pollutants in wastewater (e.g., nitrophenol and its substituted compounds) into high-value-added products holds great promise for green chemistry and sustainable development. Here, we realized the metal-free electrocatalytic reduction of 4-nitrophenol (4-NP) to 4-aminophenol (4-AP) at large current densities (∼300 mA cm⁻²) and a faradaic efficiency >72%, and the production rate reaches 0.64 mmol cm⁻² h⁻¹. To resolve the product–electrolyte separation problem, we designed a three-chamber flow cell with the cation-shuttling effect, which enables in situ purification of the product during electrochemical reactions at industrial-scale current densities. At 200 mA cm⁻², the reactor achieved ∼97% yield of the 4-AP product with a negligible electrolyte after 8 hours and there was almost no electrolyte present. We further directly used the obtained 4-AP solution and successfully synthesized the antipyretic medicine, paracetamol. This further validates the feasibility of our in situ separation method. This work demonstrates a novel electrocatalytic method for conversion of nitrophenol pollutants into important chemicals without the costly purification process.

Desulfurized gypsum (DG), a large-volume industrial by-product, was repurposed as a green sulfidation reagent for the recovery of cuprite through a sustainable sulfidation roasting–flotation process. Thermodynamic analysis confirmed that DG can effectively react with cuprite under a clean hydrogen (H₂) atmosphere, producing CuS and Cu₂S without generating SO₂. Sulfidation relies on solid-state reactions between CaSO₄ and Cu₂O, where CaSO₄ is reduced to CaS and CaO, thereby replacing conventional sulfur-based reagents that release toxic gases. The effects of roasting temperature, time, DG dosage, and H₂ concentration on flotation performance were systematically examined. Under optimal conditions (350 °C, 30 min, DG dosage 1.0, and 40% H₂), a maximum copper recovery of 89.19% was achieved with zero secondary emissions. The sulfidation reaction initiated at the mineral surface and progressed inward, forming a mesoporous (∼4.2 nm) layer. Contact angle measurements indicated a continuous increase in hydrophobicity with temperature, reaching 87.13° after collector adsorption at 350 °C. A two-stage particle growth kinetic model was developed to quantitatively describe the sulfidation behavior. This study demonstrates a clean, waste-to-resource approach for copper recovery from oxide ores, providing a feasible route toward emission-free metallurgical processing.

It is a challenge to enable non-precious metal-based electrodes to exceed the ultra-high alkaline HER activity of Pt-based precious metals by constructing a ‘vacancy–dopant structure’ with controllable vacancy concentration. Density functional theory (DFT) calculations revealed that the ‘P vacancy (Pv)–Cr dopant structure’ stimulates a significant enhancement-tandem effect during the alkaline HER process. This enhancement effect is reflected in enhanced conductivity and the adsorption capability of H₂O and OH*, thereby reducing the reaction energy barrier. Simultaneously, the tandem effect induces the Cr dopant near Pv as a unique OH* adsorption site, thereby activating the Ni(Pv)–P–Cr(Pv) mechanism that effectively prevents the poisoning of Ni hydrophilic sites and optimizes the alkaline HER pathway. Based on these findings, Cr–NiPv/IF with the ‘Pv–Cr dopant structure’ was innovatively constructed using the ‘phosphorization-quenching’ technique. Interestingly, the quenching temperature difference is positively correlated with the Pv concentration. Under the enhancement-tandem effect of the ‘Pv–Cr dopant composite structure’, Cr–NiPv/IF only requires 240 mV to deliver 1 A cm⁻² for alkaline HER, which is 3.04-fold higher than that of Pt/C@IF. This work offers a novel design concept for constructing non-precious metal-based electrodes that surpass the performance of Pt-based electrodes.

The condensation of aldehydes with o-phenylenediamine or 2-aminobenzamide followed by oxidation is an efficient method for synthesizing benzimidazoles and quinazolinones. From a green chemistry perspective, developing a catalyst capable of preparing these heterocyclic compounds via one-pot aerobic oxidation is highly desirable. The catalysts involved in this process must possess both acid catalytic and oxidation catalytic sites. Based this, we employed polyoxovanadates (POVs) as building blocks owing to their ability to activate oxygen, and obtained the POV-based MOF Zn₄(azpy)₈(V₂O₆)₄ (1) (azpy: 4,4′-azopyridine), in which Zn²⁺ exhibits a six-coordinate configuration, via hydrothermal synthesis. By adjusting the reaction temperature, the configuration of Zn²⁺ was converted to four-coordinated, and Zn₈(azpy)₈(V₂O₇)₄·H₂O (2) was obtained, successfully constructing Lewis acid sites. In addition, as increasing the specific surface area of the catalyst will improve its catalytic efficiency, we incorporated the less-polar solvent acetonitrile to modulate the particle size of 2 during the synthesis, and ultimately obtained 2-NP nanoparticles with a diameter of approximately 50 nm. In the catalytic synthesis of benzimidazoles and quinazolinones, 2-NP demonstrated outstanding performance, effectively activating oxygen from air to produce singlet oxygen at room temperature for the swift formation of benzimidazoles. Additionally, at 90 °C, the singlet oxygen can be further oxidized to generate superoxide radicals, facilitating the formation of quinazolinones. The above strategy provides a new guiding principle for the selective synthesis of MOF catalysts.

Wood is a lightweight, renewable architectural material; however, its low polarity and declining stability under repeated friction significantly hinder its practical deployment in triboelectric nanogenerators (TENGs) for intelligent residential system. Here, we present an interfacial engineering strategy that promotes in situ uniformly dense growth of metal organic framework (MOF) on the wood surface by leveraging an ionic liquid to create a porous ionogel matrix. This approach effectively reconstructs the wood surface microstructure, promoting strong interfacial adhesion between the lignocellulosic matrix and MOF crystals, thereby enhancing the mechanical strength (109.4 MPa), impact resistance (96.6 kJ m⁻²), wear resistance, and thermal stability of wood. TENGs fabricated using MLFW demonstrate stable electrical output over more than 100 000 contact-separation cycles. This work not only introduces a novel and scalable strategy for the value-added functionalization of wood offering promising opportunities for sustainable energy harvesting and smart control applications in next-generation intelligent residential environments but also demonstrates a thoughtful integration of green chemistry principles by utilizing renewable lignocellulosic feedstocks, minimal and recyclable solvents, energy-efficient processing via microwave and ambient-condition MOF growth, and modular design that supports reusability and upcycling. The approach directly supports the development of circular, smart material systems aligned with sustainable electronics.

Defect regulation represents a crucial strategy for enhancing the separation efficiency of photogenerated carriers. In this study, a V-CoMoMOF (V-CMM) catalyst with Co and Mo dual-metal defects was synthesized via NaOH etching. It was then combined with CdZnS (CZS) to form a type-I heterojunction. The composite photocatalyst CZS/V-CMM-20% with bimetallic defects shows high-efficiency hydrogen evolution activity (1525 μmol) within 5 h, which is approximately twice that of CZS/CMM. Moreover, CZS/V-CMM-20% exhibits notable hydrogen evolution performance (258.9 μmol) from polyethylene terephthalate (PET) waste under the same conditions. Density functional theory (DFT) calculations demonstrate that the introduction of bimetallic defect sites markedly enhances charge-transfer dynamics and promotes the kinetics of surface catalytic processes. Moreover, the formation of type-I heterojunctions confines both electrons and holes within the same semiconductor, leading to localized exciton states that enhance light absorption. This study provides novel insights into the design of defect-engineered composite photocatalysts, and proposes a promising strategy for the conversion of waste plastics into hydrogen energy.

Chitin nanowhiskers (ChNWs) are increasingly recognized for their potential in bio-based nanomaterials, yet a comprehensive understanding of how biomass source affects nanowhisker properties remains limited. In this study, a single-step ionic liquid pulping method was applied to isolate ChNWs from shrimp shells, squid pens, crab and lobster shell mixtures, black soldier fly larvae, and commercial chitin. Characterization via TEM, pXRD, FTIR, and TGA revealed significant differences in morphology, crystallinity, and thermal stability, attributable to chitin polymorphs and the structural organization of the native matrices. Insect-derived ChNWs exhibited the highest crystallinity and aspect ratios, while squid-derived β-chitin nanowhiskers showed a broader length distribution and reduced thermal stability. These findings emphasize the importance of biomass origin in tailoring ChNW properties and provide a unified platform for selecting regionally available feedstocks in the design of next-generation chitin-based materials. A structure–property framework for diverse chitin sources under consistent processing conditions is established, offering a strategic pathway for sustainable and localized biopolymer valorization.

Urgent sustainability efforts are needed, particularly in resource-intensive industries such as the pharmaceutical sector. Pharmaceuticals (“drugs”) are made up of active pharmaceutical ingredients (APIs) and excipients. Excipients are essential components in drug formulations. They play a significant role for the applicability of drugs. In recent years the environmental impact of APIs received much attention. In contrast, the environmental impacts of excipients most often are not considered. Here, we systematically evaluate the environmental impacts of 38 pharmaceutical excipients through cradle-to-gate life cycle assessments (LCAs) and environmental biodegradability analysis. This integrated approach provides environmental scores for excipients. Our findings identify critical environmental hotspots, particularly in excipient application fields such as binders. This calls for greener, more sustainable alternative excipients. As a key outcome, the “Excipient Selection Guide” is introduced based on a database which provides data for relative ranking to environmental issues. It will enable the pharmaceutical industry to determine whether new or existing alternatives truly represent a more sustainable choice. The data and the method can be used to design novel, greener, and more sustainable excipients of the future (“Benign by Design”). While focused on the application for pharmaceuticals, the guide's principles and data are applicable to other sectors, including food, chemistry, cosmetics, and personal care, supporting sustainability across industries where the same compounds are used.

The synthesis of fine chemicals using biomass-derived reagents has already emerged as one of the most urgent challenges, for which, many alternative green approaches to the well-known organic transformations need to be developed. In line with this concept, a novel green process for the heterogeneous catalytic acceptorless dehydrogenative coupling (ADC) of benzamidine and biomass-derived alcohols to pyrimidines is presented in this work. In contrast to the well-established heterogeneous Pt/C catalysis (EcoScale of 64) operating under harsh reaction conditions, we are able to build a green process (EcoScale of 81) based on the use of LaCoO₃ perovskite catalyst allowing an exclusively selective (84% isolated yield of pyrimidine) cyclization at ∼80 °C within only 8 hours even in a green solvent (2-Me-THF). In addition, the structure–activity relationship of this catalyst was also successfully uncovered, showing a cooperatively acting catalyst. In particular, the La(III)–O²⁻ sites can govern the activity of the catalyst, while the Co(III)–O²⁻ centers dictate the selectivity of the perovskite. Furthermore, the LaCoO₃ structure proved to be a recyclable and highly substrate-tolerant promoter, which is essential for producing substituted pyrimidines.

We report here the application of polyetherureas as a new class of aqueous binder for the LiFePO₄ positive electrode material in lithium-ion batteries. Polyetherureas have been synthesized by ruthenium-catalyzed dehydrogenative coupling of polyethylene glycol diamine and methanol avoiding conventionally used toxic diisocyanate feedstock. The best binder performance was obtained when polyetherurea was used in combination with SBR (Styrene-Butadiene Rubber), exhibiting a coulombic efficiency of ∼99.9% and a cell polarization of 30 mV. Remarkably, the combination of polyetherurea/SBR as a binder demonstrates comparable performance as that of CMC (carboxymethyl cellulose), which is a commonly used aqueous binder for lithium-ion batteries. Evidence of the involvement of polyetherureas in binder performance has been provided using IR spectroscopy and scanning electron microscopy. Physical, electrochemical, and mechanical properties of the polyetherurea have been studied using TGA, DSC, powder XRD, cyclic voltammetry, nanoindentation, tensile testing, and 180° peel test that shed light on why this polymer acts as a good binder.