SCIENCE CHINA Materials•2026•DOI: 10.1007/s40843-025-3583-6
Water scarcity and the increasing demand for clean water have driven the development of efficient solar desalination technologies. Interfacial solar steam generation (ISSG) is promising, yet its practical deployment is hindered by insufficient light harvesting and salt crystallization on photothermal surfaces. Here, we report a Janus hydrogel evaporator in which tubular Co9S8 nanocrystals are uniformly embedded in a polyvinyl alcohol (PVA) matrix with a concave pyramid pattern, creating a broadband light-trapping architecture (200–2500 nm) with 96% solar absorption. The top surface is further coated with hydrophobic zeolitic imidazolate framework-8 (ZIF-8), while the bottom retains intrinsic hydrogel hydrophilicity, establishing asymmetric wettability that sustains rapid water supply yet suppresses salt deposition. Under one-sun illumination (1 kW m−2), the Janus evaporator achieves an evaporation rate of 2.69 kg m−2 h−1 and a solar-to-vapor efficiency of 98.15%. Continuous operation in 3.5 wt% brine shows stable performance for 11 h without observable salt crystallization. This work offers an effective, durable pathway toward high-performance solar desalination and wastewater purification.
Environmental Chemistry•2026•DOI: 10.7524/j.issn.0254-6108.2025062404
To investigate the pollution characteristics and temporal variations of water-soluble ions in atmospheric fine particulate matter (PM2.5) during autumn and winter in Taiyuan City, continuous sampling and analysis were conducted using a Swiss Metrohm ion chromatograph in autumn and winter 2023. The results show that the daily mean concentration of nine water-soluble ions was 26.04 μg m−3, accounting for 52.1% of the average PM2.5 mass concentration. Ion concentrations ranked in descending order: NO3−, NH4+, SO42−, Cl−, K+, Na+, Ca2+, F−, and Mg2+. Secondary inorganic ions (SNA) constituted 87.6% of total water-soluble ions. The mass ratio of NO3− to SO42− reached 1.83, indicating a shift from sulfate-dominated to nitrate-dominated aerosol chemistry. During pollution episodes, water-soluble ion concentrations increased exponentially, with distinct ion-specific trends: on moderately polluted days, SO42− increased to 5.31 times that on clean days, whereas on heavily polluted days, NO3− increased to 5.37 times, highlighting nitrate as a primary driver of severe pollution. Comparison with historical data reveals a recent increase in the proportion of water-soluble ions in PM2.5, with higher proportions during more polluted periods. Analysis of NH4+ forms and PM2.5 acidity suggests that acidic components contribute more under heavier pollution. Positive matrix factorization (PMF) identified four major sources: secondary sources, combustion and motor vehicles, industrial sources, and dust. The secondary source contributions were 45.4%, 64.7%, and 63.4% on clean, lightly polluted, and moderate-to-heavy polluted days, respectively, indicating a significantly higher secondary contribution on polluted days.