In response to the growing challenge of photovoltaic waste management, developing sustainable and value-added treatment strategies is imperative. In this study, ethylene-vinyl acetate (EVA) resins sourced from waste photovoltaic modules and virgin materials were utilized for the production of hierarchical porous carbon (HPC) and methane-rich combustible gas via autogenic pressure pyrolysis coupled with KOH activation. Temperature-dependent pyrolysis revealed that 700 °C was the optimal condition, yielding pyrolysis gas with a high methane content (43.39 vol%) and producing graphitized carbon spheres. Subsequent KOH activation generated HPC with a large specific surface area of 765.4 m 2 /g. When applied as a supercapacitor electrode in 6 mol/L KOH electrolyte, the HPC exhibited a high specific capacitance of 152 F/g at 0.2 A/g. Additionally, EVA resins with higher vinyl acetate content and melt index (MI) produced greater amounts of methane and pyrolytic carbon, while the resins with lower MI values showed enhanced reactivity toward chemical activation. This work offers a green and efficient route for the high-value recycling of EVA in PV waste and contributes to the sustainable synthesis of advanced HPC materials for energy storage applications.
Boan Cui,Jiahao Zhao,Yuanyuan Liu,Gangqiang Wu,Jinlong Cui
Si-based hydrolysis hydrogen production is considered a promising green hydrogen generation technology due to its ability to rapidly release hydrogen under ambient temperature and pressure, with non-toxic and pollution-free reaction products. However, the intrinsic chemical inertness of silicon and the rapid formation of a dense SiO 2 passivation layer on its surface in aqueous environments severely hinder its reaction with water, thereby limiting the hydrolysis reaction rate and hydrogen production efficiency. In this work, waste silicon powder was mixed with calcium hydride (CaH 2 ) via ball milling to prepare Si/CaH 2 composite materials. The key factors influencing their hydrolysis performance were investigated by varying the ball milling time and hydrolysis conditions. The Si/CaH 2 @15h sample exhibited a high hydrogen yield of 1049 mL/g and an impressive hydrogen generation efficiency of 91.06 % when hydrolyzed in 0.5 M NaF solution. This composite material also demonstrated excellent hydrogen generation performance in fuel cell testing, achieving effective hydrogen-to-electricity conversion. This study provides a new approach for Si-based hydrolysis hydrogen production and photovoltaic resource recycling, offering a scalable method for fuel cell applications.
Although several Si/C composite structures have been proposed for high-performance lithium-ion batteries (LIBs), they have still suffered from expensive and complex processes of nano-Si production. Herein, a simple, controllable oxygen inward diffusion was utilized to transform Si sludge obtained from the photovoltaic (PV) industry into the nano-Si/SiO x structure as a result of the high diffusion efficiency of O inside Si and high surface area of the sludge. After further process, a yolk/shell Si/C structure was obtained as an anode material for LIBs. This composite demonstrated an excellent cycling stability, with a high reversible capacity (∼ 1250 mAh/g for 500 cycles), by void space originally left by the SiO x accommodate inner Si expansion. We believe this is a rather simple way to convert the waste Si into a valuable nano-Si for LIB applications.
危险品化学品经营许可证（带存储）