SCIENCE CHINA Materials•2026•DOI: 10.1007/s40843-026-4260-5
Lithium-sulfur batteries (LSBs) are recognized as a leading candidate for next-generation energy storage due to their high theoretical specific capacity (1675 mAh g⁻¹). However, the shuttle effect of lithium polysulfides (LiPSs) severely limits cycle life and energy efficiency. Here, we report a multi-interface engineering strategy employing a MnO₂-TiO₂@Ti₃C₂ MXene (MT@MX) heterojunction, synthesized via a facile redox reaction between MXene and KMnO₄, to modulate bidirectional polysulfide conversion. The 2D structure with high conductivity and abundant heterogeneous interfaces facilitates fast ion/electron transfer, reduces reaction energy barriers, and enhances adsorption via d-band center effects. The stepped built-in electric field (BIEF) in MT@MX lowers the migration energy barrier of LiPSs from catalytic MXene to TiO₂ and then to adsorptive MnO₂, enabling reversible migration across multi-interfaces. Optimized heterointerfaces synergistically integrate adsorption, diffusion, and catalytic conversion, yielding excellent cycling stability even at a high sulfur loading of 6.4 mg cm⁻². This work demonstrates that constructing heterojunctions with stepped BIEF offers a feasible approach to modulate interfacial diffusion and provides a new design strategy for high-performance LSB electrocatalysts.
Chinese Journal of Environmental Engineering•2026•DOI: 10.12030/j.cjee.202510013
To investigate the spatiotemporal distribution of nutrients and chlorophyll-a (Chl-a) in Dongping Lake, a coupled hydrodynamic-water quality-ecological model was developed using Delft3D. The model simulated total nitrogen (TN), nitrate nitrogen (NO3-N), ammonia nitrogen (NH4-N), total phosphorus (TP), soluble reactive phosphorus (SRP), and Chl-a. After validation, the model systematically analyzed the spatiotemporal patterns and influencing factors, revealing nitrogen and phosphorus transformation pathways. Results showed three temporal phases: relatively stable concentrations from January to April, significant fluctuations from May to August, and gradual stabilization from September to December, with peak timing varying among indicators. Spatially, concentrations were generally higher in the south and lower in the north, but NH4-N, TP, and Chl-a exhibited reverse patterns (higher in north) during certain periods. External inputs, primarily from the Dawen River, dominated the overall distribution, while water temperature, dissolved oxygen, and hydrodynamic conditions further modulated internal variability. Nitrogen and phosphorus showed distinct fates: nitrogen was primarily removed via denitrification and anammox, whereas phosphorus tended to transform into particulate forms and remained in the lake for extended periods. These findings provide scientific support for precise water quality management in Dongping Lake.