SCIENCE CHINA Materials•2026•DOI: 10.1007/s40843-025-3819-7
Selective solar-driven aerobic oxidation of biomass derivatives into valuable chemicals under ambient conditions is pivotal for sustainable chemical manufacturing but faces challenges from the conflict between O2 activation kinetics and selective C–H bond cleavage. This work demonstrates a spatial decoupling strategy in a precisely-engineered 2D/2D g-C3N4/ZnIn2S4 architecture, where ZnIn2S4 domains selectively activate O2, while adjacent g-C3N4 modulates electron transfer to O2 and tailors 5-hydroxymethylfurfural (HMF) binding configuration for selective C–H bond cleavage. This enables efficient selective conversion of HMF to 2,5-diformylfuran (DFF) via ambient aerobic photooxidation. When used alone, ZnIn2S4 produces mixed reactive oxygen species (·O2−/·OH) due to uncontrolled electron transfer during O2 activation. In-situ spectroscopy, Kelvin probe force microscopy (KPFM) and density functional theory (DFT) calculations demonstrate that the 2D/2D heterojunction, driven by its directed electric field, selectively activates O2 into ·O2− at ZnIn2S4 domains while suppressing ·OH generation by moderate electron transfer, mitigating over-oxidation. Adjacent g-C3N4 domains precisely anchor HMF via –OH group interactions, steering selective DFF formation. This spatial decoupling achieves a remarkable HMF-to-DFF photo-conversion rate of 1517.5 μmol g−1 h−1 with 99.4% selectivity under ambient air, outperforming many reported state-of-the-art catalysts and maintaining durable cycling performance. The work establishes a spatial decoupling principle to overcome O2 activation kinetics and site competition thermodynamics, paving the way for advanced catalyst design for sustainable energy and the environment.
Environmental Chemistry•2026•DOI: 10.7524/j.issn.0254-6108.2026012804
This study conducted online monitoring of volatile organic compounds (VOCs) at a roadside site on a main arterial road in Haikou, a tropical city, during summer 2023 (June 25–September 30). A total of 56 VOCs were measured. The mean total VOC concentration (φ(TVOCs)) was (9.05 ± 6.24) nmol·mol−1, with concentrations in the order: alkanes > alkenes > aromatic hydrocarbons > alkynes, dominated by light alkanes. Alkenes and aromatic hydrocarbons contributed significantly to atmospheric chemical reactivity, while secondary organic aerosol formation potential (SOAFP) was limited, influenced by both VOC concentrations and temperature. VOC concentrations exhibited a pronounced bimodal diurnal pattern, consistent with traffic peaks. Ratio analysis indicated a Toluene/Benzene (T/B) ratio slightly higher than typical vehicle exhaust values, and an iso-Pentane/n-Pentane (i/n) ratio suggesting fuel evaporation influence. Positive Matrix Factorization (PMF) identified four sources: gasoline/LPG vehicle exhaust (49.9%), solvent use or vehicle evaporation (26.1%), diesel vehicle exhaust (14.9%), and biogenic sources (9.1%). SOAFP was mainly contributed by solvent use/evaporation (35.7%), gasoline/LPG exhaust (34.6%), diesel exhaust (22.0%), and biogenic sources (7.7%). These findings indicate that under tropical summer high-temperature conditions, roadside VOC pollution is predominantly traffic-related, with vehicle evaporation sources non-negligible, providing insights for evaluating vehicular impacts on particulate pollution.
Environmental Chemistry•2026•DOI: 10.7524/j.issn.0254-6108.2026051001
Haikou, a representative tropical city in China, experiences air pollution influenced by both local emissions and regional transport. This study analyzed O3 and PM2.5 concentrations, emission sources, and meteorological fields from Haikou and Guangdong-Guangxi cities in 2024, employing correlation analysis and the Weighted Potential Source Contribution Function (WPSCF) to systematically investigate spatial-temporal patterns, regional linkages, and transport mechanisms. Results revealed distinct pollution characteristics: Hainan exhibited prominent O3 pollution in autumn and winter, while the Pearl River Delta (PRD) in Guangdong suffered significant O3 pollution year-round, positioning it as the core control area. Guangxi was characterized by severe PM2.5 pollution in winter with extensive high concentration areas. Haikou's O3 and PM2.5 concentrations showed strong correlations with those in Zhanjiang and Maoming throughout the year, particularly in winter. Regional transport analysis indicated that O3 pollution in Haikou depended on stable cross-regional precursor transport coupled with intense photochemical conditions, whereas PM2.5 exhibited diverse transport pathways across seasons. Lag effect analysis confirmed that pollution exceedance days were substantially influenced by upwind transport from the previous day, highlighting the dominant role of cross-regional physical transport. Autumn pollution was driven by stable surface northeasterly winds and upper-level uniform pressure fields. Potential source areas were highly consistent with the MEIC emission inventory, confirming distinct contributions of transport pathways for O3 and PM2.5. These findings provide a scientific basis for differentiated collaborative control of air pollution in tropical coastal cities.