New Carbon Materials•2026•DOI: 10.1016/S1872-5805(26)61069-4
Four-directional dual-matrix C/C composites were fabricated from PAN-based carbon fibers using a combined approach of soft-hard hybrid weaving preform molding, chemical vapor infiltration (CVI) of pyrolytic carbon (PyC), and high-pressure impregnation and carbonization of pitch-derived carbon. The ablation resistance was evaluated in a dual-pulse solid rocket motor, and the ablation behavior was investigated. The carbon rods, formed by twisting and carbonizing fiber bundles, exhibited a hexagonal cross-section, surrounded by a dense PyC 'wall' structure. The linear ablation rates after pulse I and pulse II were 0.068 mm/s and 0.113 mm/s, respectively. A cellular-like PyC layer and nanowire structures were deposited on the surface of the throat convergent section during the post-combustion cooling phase, while cracks and delamination occurred on and within the divergent section. The ablation process involved ultra-high temperatures, high-speed gas scouring, oxygen-containing thermochemical ablation, and thermal shock. This work elucidates the ablation behaviors under dual-pulse conditions and provides technical guidance for designing C/C composites for extreme environments.
Environmental Chemistry•2026•DOI: 10.7524/j.issn.0254-6108.2024092906
Microplastic pollution in rivers and lakes has become a research hotspot, yet studies in Anhui Province have predominantly focused on northern and central regions, leaving southern Anhui under-investigated. This study addresses that gap by examining the Xin'an River in Huangshan City, a typical river in southern Anhui. Surface water and sediment samples were collected in December 2023. In surface water, microplastic concentrations ranged from 350 to 3700 n·m−3, with particles of 0–0.5 mm dominating (33.93%). Fibrous shapes were most prevalent (59.83%), and colored particles accounted for 50.27%. In sediments, concentrations ranged from 25 to 200 n·kg−1, with 0–0.5 mm particles again dominant (49.63%). Fibers comprised 47.08% of sediment microplastics, and white particles accounted for 34.74%. Polymer analysis identified polyethylene terephthalate (PET) as the most abundant material (36.61%), followed by polyamide (PA) (23.22%). Source analysis suggests that fibrous microplastics originate primarily from fiber-based products such as clothing, home textiles, and fishing nets. These findings provide essential baseline data for water resource management, pollution assessment, and ecological remediation of the Xin'an River.
Journal of Environmental Engineering Technology•2026•DOI: 10.13205/j.hjgc.202606009
The escalating volume of municipal solid waste in China necessitates effective disposal strategies. Industrial kiln co-processing offers a promising route, but high-temperature decomposition of chlorinated components releases HCl and Cl2, causing severe equipment corrosion and operational issues. This study investigates the high-temperature dechlorination performance of fly ash and red mud, two abundant industrial solid wastes, as potential dechlorination agents. Using a high-temperature tube furnace system, dechlorination efficiencies were evaluated across 600–900 °C. At 700 °C, fly ash achieved a peak dechlorination efficiency of 93.33%, while red mud reached 88.61%. However, efficiencies declined with further temperature increase, dropping to 65.6% and 58.27% at 900 °C for fly ash and red mud, respectively. To enhance performance at higher temperatures, fly ash was modified via alkali (NaOH) treatment. The modification increased surface roughness and porosity, disrupted Si-O-Si and Si-O-Al networks, and exposed active sites. Consequently, the alkali-modified fly ash exhibited a peak dechlorination efficiency of 94.98% at 800 °C, a 23.08% improvement over unmodified fly ash (71.9%). These findings demonstrate the technical feasibility of utilizing solid wastes as dechlorination agents, offering a dual benefit of waste valorization and cost-effective high-temperature gas purification. The study provides a foundation for scaling up this approach in industrial kiln applications, contributing to sustainable waste management and reduced environmental impact.
Journal of Environmental Engineering Technology•2026•DOI: 10.13205/j.hjgc.202607019
This study investigated the effects of biochar on volatile fatty acids (VFAs) production, biogas composition, physicochemical properties of the fermentation broth, and microbial community structure through batch anaerobic fermentation experiments using food waste as the substrate. The results demonstrated that the addition of biochar (1 g/L) significantly enhanced VFAs production, with the total VFAs concentration reaching 2150 mg/L in the biochar group, which was 30.2% higher than that of the control group (1651 mg/L). Acetic acid, propionic acid, and butyric acid were identified as the primary VFAs components. In the fermentation system, biochar exhibited a notable pH-buffering effect, stabilizing the fermentation environment. Additionally, its porous structure adsorbed ions during the fermentation process, resulting in a slightly lower electrical conductivity compared to the control group. Microbial community analysis revealed that biochar addition enriched key acidogenic bacteria, such as Defluviitoga and norank_f__Family_XI, optimizing the microbial community structure, and thereby facilitating organic acid production. In summary, biochar effectively promoted the efficient accumulation of VFAs during anaerobic fermentation of food waste by improving the fermentation microenvironment, enhancing system buffering capacity, and regulating microbial community composition. These findings provide theoretical support for sustainable enhancement of resource utilization of food waste.
Journal of Fuel Chemistry and Technology•2026•DOI: 10.1016/S1872-5813(26)60666-4
The catalytic hydrogenation of CO2 to ethanol is a pivotal technology for carbon neutrality and high-value chemical production. Cobalt-based catalysts, with their unique electronic structure and tunability, are promising for this reaction, yet challenges persist: low single-pass CO2 conversion, ethanol selectivity below 60%, and rapid deactivation. This review systematically analyzes recent progress, establishing the thermodynamic and kinetic framework, and dissecting molecular-level mechanisms, particularly C–C bond formation and controlled oxygen removal. It critically evaluates synergistic effects among metallic Co, Co2C, CoOx, and bimetallic configurations, emphasizing structure-activity relationships influenced by supports and promoters. Inverse catalysts and tandem systems are reviewed, along with water's role as a hydrogen source. The review identifies shortcomings and advocates for advanced in situ/operational characterization and theoretical modeling to guide next-generation catalyst design. Key findings from cited studies include: Co/La4Ga2O9 achieving high selectivity (reference [85]); K-loaded Cu/CoOx boosting ethanol production (reference [86]); Ga-promoted CuCo catalysts with Cu-CoGaOx interfacial sites (reference [88]); and Mo-tailored CoFe alloys suppressing over-carburization (reference [89]). These insights provide a framework for developing efficient cobalt-based systems, deepening mechanistic understanding, and accelerating sustainable ethanol production.
SCIENCE CHINA Materials•2025•DOI: 10.1007/s40843-025-3455-4
Seawater uranium extraction is constrained by ultra-low uranium concentration (~3 ppb), high salinity, competing ions, and dynamic marine conditions. Electrochemical uranium extraction (EUE) offers high efficiency and controllability by promoting uranyl ion migration and reduction-deposition, but conventional EUE requires elevated voltages that trigger side reactions and limit selectivity. Recent advances in cathode materials—amidoxime, phosphate, and other uranyl-binding ligands—have improved adsorption capacity, yet most systems deposit uranium only at the cathode, underutilizing the electrochemical cell. Wang et al. (2025) introduce a bipolar EUE system that replaces the oxygen evolution reaction with low-potential copper oxidation, reducing cell voltage to 0.6 V. This enables simultaneous uranium extraction at both electrodes: at the anode, Cu(0) oxidizes to Cu(I), forming Cu–OH bonds that adsorb U(VI)O2^2+; in the presence of Cl−, Cu(I) transforms into Cu2(OH)3Cl, concurrently facilitating uranium capture. The bipolar design achieves long-term stability, selectivity against competing ions, and reduced energy consumption compared to traditional EUE systems. This breakthrough addresses the trade-off between extraction performance and energy input, offering a scalable pathway for sustainable uranium recovery from seawater.