SCIENCE CHINA Materials•2026•DOI: 10.1007/s40843-025-3699-1
Dual-atom (DA) catalysts have exhibited great potential in regulating the catalytic performance of CO2 reduction. However, precise construction of DAs on a support remains challenging. Herein, we report the precise immobilization of M-DAs (M = Ru, Rh, Pt) onto the Zr-oxo cluster of a 2D porphyrinic metal-organic framework (2D-Ni-PCN-222) via a dimetallic complex pre-coordination strategy. The resultant M-DAs/2D-Ni-PCN-222 catalysts were applied to CO2 photoreduction using ammonia borane as the H* donor. Under visible light, the optimal catalyst, Ru-DAs/2D-Ni-PCN-222, exhibited a HCOO− production rate of 35.4 mmol g−1 h−1 with nearly 100% selectivity and a turnover frequency of 691 h−1. Kinetic isotope experiments demonstrated that the coupling rate between H* and CO2 governed the production efficiency of HCOO−. In situ experiments and density functional theory calculations disclosed that Ru-DAs with highly delocalized d electrons could accept photogenerated electrons from 2D-Ni-PCN-222 and inject them into inert CO2 molecules. Ab initio molecular dynamics simulations revealed that adaptive shortening of Ru–O coordination bonds during CO2 adsorption played a crucial role in facilitating deeper activation and the formation of an optimal η3–O,C,O adsorption mode of CO2. This work provides a precise strategy for constructing dual-atom catalysts on MOFs and elucidates the mechanism of CO2 photoreduction, offering insights for the design of efficient photocatalysts.
Environmental Chemistry•2026•DOI: 10.7524/j.issn.0254-6108.2024112603
Sulfamethoxazole (SMX) and microplastics (MPs) are ubiquitous co-existing pollutants in aquatic environments. This study investigated the effects of polyethylene (PE), polypropylene (PP), and polystyrene (PS) MPs with varying aging degrees on the photodegradation of SMX. In the absence of MPs, SMX photodegradation was only 28%, while the presence of virgin PE increased it to 34%. Aging PE for 200, 400, and 600 h further enhanced degradation to 46%, 56%, and 77%, respectively. Pseudo-first-order kinetics showed that the rate constant (kobs) increased from 0.066 h−1 to 0.224 h−1 with aged PE. Aged MPs generated more reactive oxygen species (ROS) under irradiation, including hydroxyl radicals (·OH), singlet oxygen (1O2), and superoxide anions (O2·−), as confirmed by radical quenching and EPR analysis. Density functional theory identified the benzene ring, five-membered heterocycle, and sulfonyl group as primary ·OH attack sites. LC-MS analysis revealed degradation products such as p-aminobenzenesulfonamide, indicating both direct and indirect photolysis pathways. This work provides mechanistic insights into antibiotic-MP interactions and informs strategies for managing co-existing pollutants.
New Carbon Materials•2026•DOI: 10.1016/S1872-5805(26)61101-8
Phenolic compounds are typical refractory organic pollutants in coal chemical coking wastewater, posing significant risks to ecosystems and human health. Conventional treatment methods are inefficient, necessitating advanced oxidation processes (AOPs). Here, we report a low-cost Fe/N–C catalyst synthesized from coal-tar pitch, a common by-product of the coal chemical industry, via a self-assembly and pyrolysis strategy using graphitic carbon nitride (g-C3N4) as a template and nitrogen source, with dicyandiamide as an auxiliary nitrogen source and FeCl3·6H2O as the iron precursor. The resulting nitrogen-doped carbon nanosheets possess abundant defects (sp3-C/sp2-C = 0.66) and atomically dispersed iron species. The Fe/N–C catalyst exhibits outstanding catalytic activity for peroxydisulfate (PDS) activation, achieving over 98% phenol degradation within 30 minutes and a 60% total organic carbon (TOC) removal rate. Mechanistic studies, including radical quenching and electron paramagnetic resonance (EPR) experiments, reveal that both radical and non-radical pathways contribute to phenol degradation, with singlet oxygen (1O2) as the primary reactive oxygen species. Electrochemical analyses demonstrate that atomically dispersed Fe sites significantly enhance interfacial electron transfer. Post-reaction characterization indicates the consumption of pyrrolic-N, C=O, and carbon defects as active sites, while graphitic-N and Fe–N structures remain stable, confirming the catalyst's stability. This work provides an economical route to convert coal-tar pitch into high-performance catalytic materials for efficient water treatment, embodying the circular economy concept of waste-to-resource utilization.
Environmental Chemistry•2026•DOI: 10.7524/j.issn.0254-6108.2025021005
Microplastic pollution in freshwater environments has escalated, leading to increased accumulation in wild fish. This study investigated the occurrence characteristics of microplastics (MPs) in the gills, gastrointestinal tract (GIT), and muscle of four wild fish species with different feeding habits from Baiyangdian Lake, China. MPs were detected in all tissues. The average abundance was highest in the GIT (11.63 ± 10.76 items/individual), followed by gills (7.44 ± 6.79 items/individual), and lowest in muscle (3.91 ± 3.16 items/individual). The majority of MPs were transparent and black fibers smaller than 0.5 mm. Polymer analysis identified polypropylene (PP) and polyethylene (PE) as dominant components. Significant differences in MP abundance were observed among species, with carnivorous and herbivorous fish (e.g., snakehead and grass carp) showing higher total MPs than omnivorous and planktivorous fish (e.g., mosquitofish and topmouth gudgeon). However, when normalized by body weight, smaller fish exhibited higher MP concentrations in the GIT, suggesting a greater risk per unit mass. This study provides baseline data on tissue-specific MP distribution in wild freshwater fish with varying feeding behaviors and habitats, highlighting the influence of trophic level and body size on MP accumulation.
Environmental Chemistry•2026•DOI: 10.7524/j.issn.0254-6108.2025030305
The rapid expansion of livestock and poultry farming has intensified the challenge of managing sludge, which contains heavy metals (primarily Cu and Zn), antibiotics, and pathogens. Calcium carbide slag (CCS), an alkaline industrial waste rich in Ca(OH)2, CaCO3, and other minerals, poses environmental risks due to its high alkalinity. This study investigates the speciation transformation of heavy metals in biochar derived from co-pyrolysis of livestock sludge and CCS under varying temperatures (400–700 °C) and mixing ratios (sludge:CCS = 1:1, 2:1, 3:1, 4:1). The results demonstrate that at 600 °C and a 2:1 mixing ratio, calcium-based compounds and SiO2 in CCS effectively immobilize heavy metals through crystal solid solution and complexation, reducing their ecological risk. Sequential extraction indicated a shift from exchangeable and reducible fractions to residual fractions, with the residual fraction of Cu and Zn increasing by up to 45% and 38%, respectively, compared to sludge-only pyrolysis. The formation of apatite phosphorus (Ca5(PO4)3OH and Ca3(PO4)2) enhances the bioavailability of phosphorus in the biochar, making it a potential slow-release fertilizer. The study provides a novel strategy for the synergistic treatment of livestock sludge and CCS, offering environmental and economic benefits by producing stable, nutrient-rich biochar while mitigating heavy metal toxicity.
Journal of Environmental Engineering Technology•2026•DOI: 10.13205/j.hjgc.202607009
Resource utilization of food waste is a key measure for implementing waste classification and constructing zero-waste cities in China. However, the technical route based on anaerobic digestion currently faces developmental bottlenecks. In this study, engineering-scale facilities located in Northeast, North, Northwest, and Southeast China were selected, and material flow analysis was employed to comprehensively assess the current status of anaerobic digestion of food waste. The results indicated that, during the pretreatment stage, both leachate and organic slurry from all surveyed regions exhibited high COD/TN ratios, and the leachate contained high concentrations of lipids. Following three-phase (oil-water-solid) separation, the oil recovery rate could reach over 98%. Anaerobic digestion of each ton of food waste from the four regions generated approximately 70 to 80 Nm³ of biogas, while simultaneously producing liquid digestate accounting for 69% to 80% of the total mass and solid digestate accounting for 2.7% to 3.6%. However, the annual continuous production of digestate was not aligned with the seasonal demand for land use, thereby restricting the pathway for resource utilization. Converting food waste into an external carbon source can significantly enhance its resource utilization efficiency, with the economic benefits increasing by more than 203% compared to the methanogenesis pathway. The selection of the carbon source production technology route should be comprehensively determined by taking into account factors such as the specific nitrogen removal requirements of the target wastewater treatment process, the quality requirements for the carbon source products, and the substitution rate of commercial carbon sources.
SCIENCE CHINA Materials•2026•DOI: 10.1007/s40843-025-3966-0
The development of low platinum-loading catalysts for the economically viable hydrogen evolution reaction (HER) remains challenging. Herein, a precursor dilution strategy is used to fabricate Pt nanoclusters anchored on Ni-embedded porous carbon microspheres. The approach begins with the facile synthesis of Zn/Ni-based coordination polymers (Ni-BTC-Zn) due to the isomorphic substitution of Zn2+ and Ni2+. During pyrolysis, the evaporation of zinc species results in a highly porous carbon structure with well-dispersed nickel nanoparticles. Subsequent solvothermal treatment allows for the uniform deposition of Pt nanoclusters to form the final bimetallic PtNi catalysts (PtNi-BTC-C). Among them, the optimized PtNi-BTC-C10 exhibits exceptional alkaline HER performance, requiring an overpotential of only 41 mV to achieve 10 mA cm−2 and a low Tafel slope of 31.1 mV dec−1. It also demonstrates outstanding durability with a current retention of 90.7% after 70 h, far exceeding Pt/C. Extensive characterization confirms that moderate Zn dilution optimally modulates the Ni particle size and dispersion, leading to maximized active sites and enhanced charge transfer. Combined with DFT calculations, the Pt-Ni-cluster model for PtNi-BTC-C10 possesses an optimized electronic structure with a shifted d-band center, which facilitates water dissociation and optimizes H* desorption with the most favorable energetics (0.262 eV). This work provides a fundamental understanding of precursor dilution engineering and offers a versatile pathway for designing advanced noble-metal-based bimetallic electrocatalysts.