Rapid Synthesis of Oxygen-Deficient MoO3–x-rGO Composites for Synergistic Photothermal Seawater Desalination and Photocatalytic Sterilization

Abstract

The development of efficient photothermal desalination devices is of great significance in solving the problem of freshwater shortage. The design and preparation of efficient photothermal materials with a broad light absorption range have been extensively studied. However, the performance of photothermal catalysts for synergistic purification of complex seawater is still facing significant challenges. Therefore, we report the rapid preparation of MoO3–x-rGO composites with synergistic photothermal and photocatalytic performance by the solid-phase microwave thermal shock method. The superhot spots created on the surface of microwave-reduced rGO induce the formation of MoO3–x with oxygen vacancies. Due to the localized surface plasmon resonance (LSPR) effect, the near-infrared photothermal and photocatalytic properties of MoO3–x-rGO catalysts are greatly improved. When the optimal composite catalyst (GMW-3) is illuminated by one sunlight, the seawater evaporation rate and photothermal conversion efficiency can reach 1.58 kg m–2 h–1 and 87.2%, respectively. Meanwhile, the GMW-3 composite evaporator shows excellent antibacterial performance under the synergistic effect of photothermal and photocatalysis during the evaporation process. These findings expand a new insight and platform to design efficient catalysts for large-scale seawater desalination and purification.