Water vapor recovery device designed with interface local heating principle and its application in clean water production

In this world, insufficient potable water resources and water pollution exist simultaneously. The photothermal device designed in this paper consists of three components: a superhydrophobic BiOBr photocatalyst layer (SH-Bi sponge), hydrophilic layer (cotton), and photothermal layer (CNTs/Co3O4). The SH-Bi sponge layer designed has two functions: (1) ensuring that the photothermal layer floats on the water surface; (2) removing the surface oil and photodegradation pollutants in sewage. h+ is identified as the main active species by studying the degradation mechanism. Meanwhile, the specific locations of the valence band (1.108 eV) and conduction band (−1.312 eV) of the BiOBr photocatalyst are determined. Local interface heating is realized through the synergistic effect between the hydrophilic layer and photothermal layer. The results demonstrate that the photothermal device has a high steam generation rate and vapour production rate for ordinary water quality and NaCl aqueous solution.