An All-in-One Feox-Rgo Sponge Fabricated by Solid-Phase Microwave Thermal Shock for Water Evaporation and Purification

Abstract

Developing high-efficiency photothermal seawater desalination device is of great significance to solve the shortage of freshwater. Though a lot of efforts have been made in photothermal materials, it is urgent to design an evaporator both with broad-spectrum absorption and high photothermal conversion efficiency. Therefore, we reported all-in-one FeO x -rGO photothermal sponges v ia solid-phase microwave thermal shock. The narrow band gap of the semiconductor material Fe 3 O 4 greatly reduces the recombination of electron-hole pairs, and the non-radiative relaxation enhanced light absorption. The abundant π orbitals in rGO promoted the excitation of electrons and enhanced the thermal vibration between the lattices. The control of the hydrophilicity and hydrophobicity of the surface promoted salt resistance, and simultaneously realized the purification of various complex polluted waters. Thus, the optimized GFM-3 sponge exhibited an enhanced photothermal conversion rate of 97.3% and the water evaporation rate of 2.04 kg m -2 h -1 , and also showed promising synergistic water purification properties. These findings not only provide a high efficient photothermal sponge for practical applications of seawater desalination and purification but also develop a super rapid processing methodology for evaporation devices.

Keywords: desalination, photothermal device, microwave synthesis, water purification, FeOx-rGO