Simultaneous Solar-driven Steam and Electricity Generation by Cost-effective, Easy Scale-up MnO2-based Flexible Membranes

Harvesting solar energy in an effective manner for steam and electricity generation is a promising technique to simultaneously cope with the energy and water crises. However, the construction of efficient and easy scale-up photothermal materials for steam and electricity cogeneration remains challenging. Herein, we report a facile and cost-effective strategy to prepare MnO 2 -decorated cotton cloth (MC x ). The wide adsorption spectrum and excellent photothermal conversion ability of the in situ-formed MnO 2 nanoparticles make the MC x to be advanced photothermal materials. Consequently, the hybrid device integrated with MC x as the photothermal layer and the thermoelectric (TE) module for electricity power conversion exhibits an extremely high evaporation rate of 2.24 kg m −2 h −1 under 1 kW m −2 irradiation, which is ranked among the most powerful solar evaporators. More importantly, during solar evaporation, the hybrid device produces an open-circuit voltage of 0.3 V and a power output of 1.6 W m −2 under 3 Sun irradiation, and outperforms most of the previously reported solar-driven electricity generation devices. Therefore, the integrated device with synergistic solar-thermal utilization opens up a green way toward simultaneous solar vapor and electric power generation in remote and resource-constrained areas.