ACS Sustainable Chemistry & Engineering最新文献

Electrolytic water splitting for hydrogen production remains a significant challenge, highlighting the urgent need for high-performance and economically viable electrocatalysts for the hydrogen evolution reaction (HER). In this study, a Ni₂P/CoSe Mott–Schottky heterojunction was fabricated on carbon fiber paper (CFP), serving as an efficient HER electrocatalyst in alkaline media. The radially aligned CoSe hollow nanoneedles enable the uniform anchoring of Ni₂P quantum dots, forming tightly coupled heterointerfaces between discrete quantum domains and the conductive scaffold, thereby increasing the density of interfacial active sites. Discretely dispersed semiconducting Ni₂P on metallic CoSe induces interfacial charge polarization via quantum confinement effects, thereby generating a strong built-in electric field (BIEF) at the interface that drives electron transfer from Ni₂P to CoSe. This field promotes interfacial charge redistribution and intrinsically activates the catalytic sites. Density functional theory (DFT) calculation reveals that interfacial charge redistribution between Ni₂P and CoSe generates electron-deficient Ni sites and electron-rich Co sites, which respectively optimize H₂O adsorption/dissociation and H* adsorption, thereby enhancing the HER activity. As a result, the 2-Ni₂P/CoSe/CFP catalyst exhibits outstanding HER performance with a low overpotential of 186 mV at 1000 mA cm^–2 and <1% loss after 300 h. Using 2-Ni₂P/CoSe/CFP as the cathode, an AEM-WE device exhibits a low cell voltage of 1.74 V at 1000 mA cm^–2 and a long-term stability for 500 h.

Multifunctional and biodegradable smart packaging films were developed here using pectin, phycocyanin rich Spirulina (PCS) extract and citric acid derived carbon dots (CDs). The physicochemical, active and intelligent properties of the films were systematically examined as a function of CD concentration. Incorporation of CDs enhanced tensile strength from 10.88 to 17.70 MPa, increased crystallinity and thermal stability and maintained high biodegradability (above 80% mass loss after 28 days in soil). The addition of CD enhanced antioxidant activity (from 12.8% to 39.5% ABTS scavenging) and imparted concentration dependent antimicrobial activity against E. coli and S. aureus. The PCSP/CD12.5 film displayed a distinct colorimetric response to ammonia vapor, displaying a linear ΔE–NH₃ correlation (R² = 0.93) within the range of 0–50 mg N/100 g and a detection limit of 9.04 mg N/100 g, and exhibited colorimetric stability over two months of storage. In real food trials, the PCSP/CD12.5 film enabled effective visual tracking of fish freshness at 23 °C with color changes closely correlating to increases in TVB-N (from 13.3 to 36.2 mg N/100 g) and TVC (from 4.5 to 7.4 log cfu/g) during storage. These results demonstrate that PCSP/CD films effectively integrate active and intelligent functionalities thereby extending the application of pigment and protein complexes.

In recent years, extensive research has been devoted to the synthesis or modification of epoxy resins from biomass-derived feedstocks. However, realizing closed-loop recyclability, using fully renewable raw materials, and preserving key material properties remain open and persistent challenges in epoxy resin development. Herein, we propose a strategy involving the use of biomass-derived tung oil (TO) as the primary raw material and employing dynamic covalent ester-exchange chemistry to prepare a highly mechanically robust, recyclable, and reprocessable tung oil epoxy resin (ECAT-ME) vitrimer. The ECAT-ME vitrimer consists of a covalent adaptable network based on an associative mechanism, exhibiting tensile and compressive strengths of 11.87 and 17.45 MPa, respectively. Following six pulverization–melting–cooling cycles, the material retained tensile and compressive strengths of 6.99 and 8.92 MPa, respectively. This recyclable, high-performance biobased epoxy resin lays the foundation for the sustainable development of functional composites.

The chemical recycling of chlorinated plastics is industrially challenging due to the release of corrosive HCl and char formation. In this work, a novel upcycling route for chlorinated plastics, including polyvinyl chloride (PVC), polyvinylidene chloride (PVDC), and chlorinated polyethylene (CPE), is developed. When ZnCl₂-catalyzed dehydrochlorination (DHC) is combined with tandem DHC-hydrogenation, using a homogeneous Ru hydrogenation catalyst and metal oxides as a HCl trap, each plastic type can be selectively converted into an unsaturated polyolefin (UPO), which can be chemically split via metathesis. By rational design of reaction conditions, CPE (25 or 35 m% Cl) as a model substrate, a PVDC–PVC copolymer (66 m% Cl) and PVC (57 m% Cl) were consecutively converted into partially and fully dechlorinated UPOs. Both of these UPO products contained −CH₂–CH₂–sequences and up to 11 double bonds per 100 carbons. They were chemically split into α,ω-dienes using a second-generation Grubbs catalyst. Via this procedure, chlorinated plastics can be converted into valuable chemical building blocks, while the released HCl is sequestered.

Coal washing plays a vital role in improving coal quality and reducing atmospheric pollutant emissions from coal combustion. However, the water footprint burdens caused by substantial freshwater consumption and wastewater discharge remain poorly understood. In this study, a comprehensive water footprint framework for coal washing was developed and used for a bottom-up analysis based on firsthand data from 2,367 coal washing plants across China in 2022. Compared with the scenario where coal was not washed, the national coal washing industry increases the water footprint by 7.38 Gm³, bringing the total water footprint of China’s coal supply chain to 27.68 Gm³, with gray water accounting for 90.9%. The water footprint intensities of commercial coal varied between 6.93 and 27.33 m³/t depending on the washing technologies, with a national average of 8.73 m³/t. Among the various technologies, jigging and jigging-based combined processes demonstrated relatively low water footprint intensities. From a production perspective, the spatial distribution of water footprint intensities in China exhibits a “high in the south and low in the north” pattern. However, an interprovincial transfer of 12.72 Gm³ of water footprint exacerbated the spatial mismatch between coal resources and water availability, owing to mismatches between production and consumption centers and prevailing trade flows. This study highlights the significant contribution of coal washing to the total water footprint of the coal life cycle and underscores the urgent need to incorporate water footprint balance into policies and decision-making regarding coal washing practices.

While anatase-TiO₂/α-Fe₂O₃ (ATAF) composites are promising visible-light photocatalysts, their conventional synthesis is hindered by prolonged processing and high-temperature calcination, which limits scalability and increases energy consumption. This work demonstrates a rapid, single-step microwave-hydrothermal strategy to fabricate phase-pure ATAF composites within 10 min, entirely without calcination. This method facilitates the heterogeneous nucleation of anatase-TiO₂ onto α-Fe₂O₃ particles, creating an intimate interface. By optimizing the α-Fe₂O₃ content with uniform TiO₂ decoration on it, an ATAF composite exhibiting superior charge separation, as evidenced by significant photoluminescence quenching, is prepared. This optimal interface engineering results in a remarkable 99.9% photocatalytic degradation of methylene blue under visible light, significantly outperforming the individual constituents. This energy-efficient approach potentially reduces synthesis energy consumption by one to 2 orders of magnitude compared to conventional calcination routes, while the use of aqueous solvents and a closed system aligns with the principles of clean production. The combined advantages of rapid processing, energy efficiency, and scalability position this method as a viable pathway for the industrial-scale production of high-performance photocatalytic composites. The microwave-assisted hydrothermal synthesis demonstrates process electrification by transitioning from conventional furnace-based thermal treatment to direct microwave heating, resulting in reduced energy consumption and associated CO₂ emissions.