Rational design of natural leather-based water evaporator for electricity generation and functional applications

In recent years, water evaporation-induced electricity has attracted a great deal of attention as an emerging green and renewable energy harvesting technology. Although abundant materials have been developed to fabricate hydrovoltaic devices, the limitations of high costs, inconvenient storage and transport, low environmental benefits, and unadaptable shape have restricted their wide applications. Here, an electricity generator driven by water evaporation has been engineered based on natural biomass leather with inherent properties of good moisture permeability, excellent wettability, physicochemical stability, flexibility, and biocompatibility. Including numerous nano/microchannels together with rich oxygen-bearing functional groups, the natural leather-based water evaporator, LeatherEmblic-NPs-SA/CB, could continuously produce electricity even staying outside, achieving a maximum output voltage of ∼3 V with six-series connection. Furthermore, the leather-based water evaporator has enormous potential for use as a flexible self-powered electronic floor and seawater demineralizer due to its sensitive pressure sensing ability as well as its excellent photothermal conversion efficiency (96.3%) and thus fast water evaporation rate (2.65 kg m−2 h−1). This work offers a new and functional material for the construction of hydrovoltaic devices to harvest the sustained green energy from water evaporation in arbitrary ambient environments, which shows great promise in their widespread applications.