PM2.5 can easily penetrate indoor spaces through natural or mechanical ventilation systems, posing a serious threat to human health. Fiber filtration is the predominant technique for indoor particulate matter purification. However, there is an inherent trade-off between achieving high filtration efficiency and maintaining low resistance. Therefore, this study employs a simple and fast adhesive method to fabricate a composite material composed of micro-biochar (BC) and polyurethane (PU) coarse fibers (BC@PU). We developed an electrostatic-assisted air filtration device system that leverages the electrostatic interaction between charged particles and polarized fibers to achieve high-efficiency, low-resistance air filtration. At a face air velocity of 0.4 m/s, the BC-1.5@PU material achieves a remarkable 98.83% removal efficiency for particles in the 0.3–0.5 μm size range, while maintaining a minimal pressure drop of approximately 7 Pa, with the best CQF (comprehensive quality factor) value of 0.408 Pa⁻¹, which was a remarkable 94.06% improvement over the bare PU material. In addition, the simulation results indicate that the micro-biochar significantly enhances the effective electric field range within the composite fibers. It indicates that this composite fiber holds great potential for air purification in ventilation systems.

This review highlights the critical effects of heat transfer and bubble mass transfer in alkaline water electrolysis on hydrogen generation efficiency. To improve heat transfer performance, the study focuses on reducing electrical resistance and controlling the electrolysis system’s temperature. It proposes innovative strategies such as using metal matrix composites and catalysts to optimize electrode structure, precise temperature and pressure regulation and enhanced electrolyte concentration. Additionally, the study examines the dynamics of bubble mass transfer, proposing effective strategies to reduce bubble coverage, including hydrophilic electrodes, mechanically circulating the electrolyte and voltage smoothing with pressure swinging. This study contributes to the advancement of hydrogen energy technology with practical strategies. By adjusting the electrolysis system to optimize the combined effect of these factors, we can improve the efficiency, economy and environmental friendliness of hydrogen production. This will contribute to the transformation of the global energy mix and the implementation of sustainable development strategies.