Advanced design of bimetal sulfide/V2CTX MXene photothermal nanocomposites for integrated solar steam generation, electricity generation, and water purification

Abstract

The utilization and conversion of solar energy is considered an environmentally friendly strategy to achieve global carbon peak and carbon neutrality. To synergistically alleviate freshwater and electricity scarcity, designing multifunctional photothermal composites that are highly efficient and stable is particularly important. Herein, a multifunctional Cu3BiS3@V2C/BF membrane with a bilayer structure has been developed, the top is Cu3BiS3@V2C-1 nanocomposite coating, and the bottom is porous BF membrane, the interface matching is achieved by coordination effect of calcium ions and carboxylate group. The Cu3BiS3@V2C-1/BF membrane can achieve a broadband absorption of ≈95.2 % in the full spectrum, benefitting from the near-infrared spectral compensation mechanism. Further, a high evaporation rate of 1.68 kg m−2 h−1 is achieved by the synergetic design of multistage photothermal conversion and the decrease in evaporation enthalpy. Moreover, the membrane has high solar desalination efficiency, electricity generation of 55 mV under one sun, and water purification performance, which profit from the unique sodiophilic property of V2CTx MXene, the enhanced photothermal catalysis and the abundant adsorption sites of Cu3BiS3@V2C-1 nanocomposite. Furthermore, the deep mechanism of photothermal conversion and photothermal catalytic is analyzed using first-principles calculation. This work is a promising approach to focus on multifunctional solar utilization in the future.