Effect of crystal defects for solar steam generation performance of black phosphorous nanosheets

Abstract What part do the crystal defects play in the solar steam generation performance of black phosphorous (BP) nanosheets, whether good or bad? Herein, through controlling the exfoliation environment, BP nanosheets with or without crystal defects (W-BP and D-BP) are successfully fabricated, and integrated into the solar steam generator with polyurethane (PU) foam. Based on TEM, SEM, and XPS technologies, crystal defects composed of phosphoric acid groups are found to be introduced into lattice structure of BP nanosheets. With simulated sunlight, the temperature variations are different in PU@collagen/D-BP (26.6 oC) and PU@collage/W-BP (20.9 oC) compared to the initial temperature. As a result, steam generation rate of PU@collage/W-BP and PU@collage/D-BP are increased to 0.6809 kg/m2h and 0.8910 kg/m2h from 0.2594 kg/m2h (pure water). This work first reveals the inherent relationship between crystal defects and the performance of BP nanosheets based solar steam generation, providing key information for the in-depth application of BP nanosheets.