Preparation of antifouling Janus photo evaporator by in-situ growth of carbon nanotubes/graphene on zeolite surface

Solar-driven interfacial evaporation (SDIE) technology is considered an efficient method for addressing the scarcity of freshwater resources and energy shortage. To enhance SDIE efficiency, photothermal materials such as carbon nanotubes (CNTs) and graphene have been explored, but their complex preparation and limited performance necessitate improvements. In this study, we propose a simple new synthesis method for in situ growth of C/G layers on zeolite surfaces and design a Janus membrane structure. The Janus membrane structure of the synthesized Geopolymer zeolite (GZ)-CNTs/graphene (C/G) composite material (GZC/GC) combines the excellent photothermal and electrical properties of the C/G layer, as well as the water transport and salt rejection properties of the GZ layer. At a current intensity of 0.5 A, the evaporation rate of hemispherical GZC/GC can reach 5.74 kg m−2 h−1. The synergistic effect of the hemispherical design of the evaporator and Janus membrane structure can further improve the evaporation rate and salt rejection performance of the device. The contribution of the Marangoni effect inside the GZC/GC evaporator to salt rejection performance has been confirmed through software simulation. In conclusion, the GZC/GC photo-evaporator represents a breakthrough in high-salinity wastewater treatment, with broad prospects for zeolites in photothermal and optoelectronic applications.