Phase-Change Microcapsules Boosting Clean Water Production and Electricity Output through Janus Bilayer Poly(vinyl alcohol)/Chitosan Composite Aerogels

under one-sun irradiation alone with good resistance to salt accumulation. Compared to a control evaporator without any phase-change microcapsules, the developed evaporator obtained an increase in the total mass change of 150% under dark conditions. Meanwhile, a thermoelectrical generator equipped with the composite aerogel exhibits an open-circuit voltage of 143.89 mV under one-sun irradiation alone with an elongated power output period of 30 min. With an innovative Janus bilayer structural design by combining a biodegradable PVA/CS aerogel with phase-change microcapsules and CB nanoparticles, this study represents a significant advancement in renewable energy utilization, particularly in sustainable water purification and hybrid energy systems. The developed Janus bilayer composite aerogel exhibits great application potential in highly efficient freshwater production and electricity generation under intermittent sunlight irradiation.