SCIENCE CHINA Materials•2026•DOI: 10.1007/s40843-026-4210-6
Achieving low-energy-loss organic solar cells requires precise regulation of energetic disorder and intermolecular packing, which remains challenging at the molecular design level. Here, we report an aza-pyran-type molecular design strategy that integrates a sp3-hybridized nitrogen-centered core with a pyran structural motif to regulate aggregation behavior and energetic disorder in non-fullerene acceptors. Two representative acceptors, D10 and D11, are developed, both exhibiting broadened absorption and high open-circuit voltages, while D10 shows more balanced aggregation and improved long-range molecular ordering. When incorporated as guest acceptors into the PM6:L8-BO system, the optimized ternary device achieves a power conversion efficiency of 19.86% with a high VOC of 0.89 V. Detailed optoelectronic analyses reveal reduced non-radiative energy loss (ΔE3 ≈ 0.23 eV), enhanced electroluminescence quantum efficiency (~1.17 × 10-4), and lowered energetic disorder (EU = 25 meV) in the ternary blends. GIWAXS and charge-transport studies further demonstrate that the introduction of D10 promotes enlarged crystalline domains and more ordered π-π stacking, facilitating balanced carrier transport and suppressed recombination. This work establishes an effective molecular design paradigm that links aza-pyran molecular engineering with energy-loss management, providing new insights into the development of high-efficiency, low-energy-loss organic solar cells.
SCIENCE CHINA Materials•2026•DOI: 10.1007/s40843-025-3761-7
Ruthenium-based materials, including metallic Ru and RuO2, are promising electrocatalysts for electrochemical water splitting (EWS) due to their high activity for both hydrogen evolution reaction (HER) and oxygen evolution reaction (OER). However, their practical application is hindered by the relatively strong adsorption of reaction intermediates on Ru surfaces and the oxidative dissolution of RuO2 under operating conditions. This review provides a comprehensive overview of recent progress and challenges in Ru-based electrocatalysts for EWS. We first summarize the fundamentals of EWS, including reaction mechanisms and activity descriptors. Then, we detail typical synthesis methods such as hydrothermal/solvothermal syntheses, organic ligand-assisted syntheses, pyrolysis, acid etching, cation exchange, and molten salt-assisted syntheses. Subsequently, we focus on enhancement strategies, including alloying, doping, structure design, interface engineering, single-atom catalyst design, high-entropy alloy design, phase engineering, and defect engineering, with typical examples illustrating structure-property correlations. Finally, we address remaining challenges and future prospects for the development of efficient and durable Ru-based electrocatalysts for sustainable hydrogen production.
Chinese Journal of Environmental Engineering•2026•DOI: 10.12030/j.cjee.202507043
Municipal sludge with high moisture content and strong viscosity tends to form a dense crust during conventional rotary drum drying, reducing heat and mass transfer efficiency and prolonging drying time. This study proposes a thermal steel ball-enhanced rotary drum drying method that introduces high heat capacity, high thermal conductivity steel balls to achieve synergistic contact heat conduction and mechanical disturbance. An evaluation system incorporating dimensionless moisture ratio (MR), drying rate (DR), characteristic drying time (tdry), effective moisture diffusivity (Deff), and volumetric evaporation intensity (U) was established. Results show that compared with conventional drying, steel ball-enhanced drying increased maximum drying rate (DRmax) by 22.59%–41.19%, U by 38.06%–93.43%, and shortened tdry by 27.56%–48.30%, with more pronounced advantages under high load conditions. Deff was significantly higher throughout the process, with maximum increase up to 48.30%, indicating that ball rolling and collision effectively disrupt the crust and promote moisture migration. Mechanistic analysis reveals that the performance enhancement arises from the dual action of thermal-mechanical coupling and mechanical disturbance, which enhances local heat flux via contact conduction and dynamically renews the drying interface, shortening diffusion paths. This study elucidates the heat and mass transfer mechanisms of thermal steel ball-enhanced sludge drying, providing theoretical support and technical reference for efficient sludge volume reduction and dryer design optimization.
SCIENCE CHINA Materials•2026•DOI: 10.1007/s40843-025-3470-6
Inkjet printing of two-dimensional transition metal chalcogenides (TMDs) is promising for low-cost, large-scale flexible electronics, yet challenges persist due to poor crystallinity and toxic solvents. Here, we report a green ink formulation using zwitterionic cocamidopropyl betaine (CAB) as a dispersant and surfactant for liquid-phase exfoliation of single-crystalline TMDs in water and isopropanol (IPA). The dispersions contain no additives or binders, enabling direct production of stable (over one month) and concentrated (2 mg/mL) inks for MoS2, MoTe2, WS2, WSe2, and WTe2. Fully-printed MoSe2/CAB humidity sensors exhibit superior sensitivity (ΔI/I0 = 468.1) and rapid response/recovery times (27 s/0.42 s) under bending. Inkjet-printed WTe2/CAB pads on 6-μm-thick substrates demonstrate exceptional mechanical stability, with resistance variations of 1.4% under single bending and 2% after 1,000 cycles, and acquire high-quality electrocardiogram (ECG) and electromyography (EMG) signals. This strategy enables scalable fabrication of TMD-based flexible electronics, advancing industrial integration.