Bifunctional photothermal membrane for high-temperature interfacial solar steam generation and off-grid sterilization

•Bifunctional photothermal membrane is engineered using cost-effective and easily available materials for solar steam generation.•Bifunctional photothermal membranes could produce high-temperature ∼ 90 °C under ambient conditions.•Efficient solar steam generation and sterilization of pathogens are achieved.