PVA/cellulose hydrogel with asymmetric distribution of MoS2 for highly efficient solar-driven interfacial evaporation and electricity generation

Abstract

Population growth and economic globalization have exacerbated freshwater shortages and energy crises, and solar-driven interfacial evaporation (SDIE) offers a promising solution due to its environmental friendliness, accessibility, and sustainability. However, the highly efficient cogeneration of freshwater and electricity using the SDIE process is a challenge. Herein, a PVA/cellulose hydrogel with asymmetric distribution of MoS2 is proposed as a highly efficient SDIE system to overcome the bottleneck in the cogeneration of freshwater and electricity. By applying material genome engineering and microstructure regulation to improve light harvesting, energy efficiency, evaporation performance, and vapor escape. The evaporation rate of the PVA/cellulose evaporator could reach 3.23 kg m−2 h−1 when desalinating 3.5 wt% seawater under 1 sun and remained basically stable during the long-term continuous evaporation. In addition to desalination, the prepared evaporator also has a potential application in the cyclic utilization of the industrial and domestic wastewater. The synergistic effect of the electron double layer effect and the seawater battery principle produces a high output voltage of 0.714 V. Meanwhile, the optimized solar evaporator demonstrates good mechanical properties, salt resistance, environmental adaptability, and carbon emission economy. This work provides new insights into efficient seawater desalination and power generation, and inspires further research on multifunctional solar-driven interfacial evaporation systems to effectively address water scarcity and energy crises.