SCIENCE CHINA Materials•2026•DOI: 10.1007/s40843-026-4165-1
Developing efficient photocatalysts for hydrogen peroxide (H2O2) synthesis is vital for sustainable chemistry, yet optimizing the electronic structure of triazine-based covalent organic frameworks (COFs) through precise spatial engineering remains a challenge. In this work, we constructed four model COFs to systematically decode how the spatial arrangement and incorporation level of triazine moieties regulate the electronic structures and H2O2 production efficiency. Combined experimental and theoretical analyses revealed that FB-AT achieved an optimal donor-acceptor architecture via rational spatial arrangement of triazine and benzene moieties. This configuration established an intramolecular potential gradient, which not only promoted charge separation by suppressing the exciton binding energy but also enriched the electron density at triazine sites. These electron-rich active centers significantly facilitated the oxygen reduction reaction by lowering the thermodynamic energy barrier for *OOH intermediate formation. Consequently, FB-AT exhibited a remarkable H2O2 production rate of 11055 μmol g-1 h-1 in pure water, along with a superior solar-to-chemical conversion efficiency of 1.16%. Additionally, FB-AT enabled complete degradation of phenol, tetracycline, and rhodamine B within 5–15 min of visible light irradiation. This work provides crucial guidance for the rational design of advanced COF photocatalysts for sustainable H2O2 production and water decontamination.
Journal of Environmental Engineering Technology•2026•DOI: 10.13205/j.hjgc.202607013
This study investigated the synergistic effects of earthworm mucus and two biochar types (rice husk biochar and straw biochar) on heavy metal bioavailability during sludge composting. Sludge was amended with earthworm mucus alone or combined with biochars at varying proportions, and the impacts on physicochemical properties, total heavy metal concentrations, bioavailable fractions, and chemical speciation were analyzed. Results showed that mucus addition increased sludge pH and electrical conductivity (EC) but decreased total nitrogen (TN) and total phosphorus (TP) contents. Synergistic mucus-biochar composting further elevated pH and EC while reducing TN, with the optimal treatment being mucus plus 10% rice husk biochar. Mucus-only composting reduced total concentrations and bioavailability of Cd, Cu, Ni, Zn, and Pb. Adding biochars significantly enhanced these reductions. Specifically, mucus with rice husk biochar achieved the best Cd removal, with total and bioavailable Cd decreasing by 27.03%–55.68% and 9.52%–28.57% (P<0.05), respectively, compared to controls. Mucus with straw biochar was most effective for Ni, Zn, and Pb, reducing total contents by 3.81%–5.72%, 7.93%–34.62%, and 42.61%–79.46%, and bioavailable fractions by 2.90%–26.31%, 15.58%–24.14%, and 32.30%–36.88% (P<0.05), respectively. Speciation analysis revealed that Cd, Ni, and Pb carbonate-bound fractions transformed into residual forms, and exchangeable fractions shifted to Fe-Mn oxide-bound forms. Straw biochar addition resulted in the highest residual fractions for Cd, Cu, Ni, Zn, and Pb, increasing by 0.35%–7.02%, 8.61%–12.90%, 16.62%–23.02%, 17.33%–26.10%, and 16.12%–27.20% (P<0.05), respectively. These findings demonstrate that earthworm mucus combined with rice husk or straw biochar effectively reduces heavy metal concentrations and bioavailability in sludge, offering a promising strategy for sludge composting.
SCIENCE CHINA Materials•2026•DOI: 10.1007/s40843-025-3917-x
The escalating global challenge of antibiotic contamination demands advanced sensing technologies for environmental monitoring and public health protection. Here, we present a structurally well-defined, intercalation-engineered metal-organic framework (MOF), HSB-W18, which functions as an ultrasensitive and selective fluorescence sensor for fluoroquinolone antibiotics. Single-crystal X-ray diffraction analysis unambiguously determined both the framework architecture and the spatial organization of intercalated 2,5-dihydroxyterephthalate molecules at atomic resolution. Through ultrasound-assisted synthesis, highly stable book-shaped microsheets (HSB-W18-MS) were obtained, maintaining exceptional aqueous dispersibility and luminescence intensity for over one month. These microsheets offer distinct advantages for antibiotic detection: specific recognition of diverse fluoroquinolones via unique fluorescence signatures; highly sensitive ratiometric detection of enoxacin (ENX) with a limit of detection (LOD) of 5.62 nM and rapid response kinetics (<30 s); exceptional selectivity alongside reusability. Systematic mechanistic investigations revealed a synergistic detection process involving multiple photophysical pathways. Furthermore, a smartphone-based portable detection system was successfully implemented, and the practical utility of the sensor was validated by quantifying ENX in complex environmental samples: tap water LOD = 18.32 nM and river water LOD = 29.87 nM. This study contributes to fundamental materials science and environmental monitoring by elucidating discernible structure-property relationships in intercalated MOFs, demonstrating a robust platform for field-deployable antibiotic detection and proposing an innovative design paradigm for environmental optical sensors.