Laser Synthesis Of Graphene Oxide Composites For Solar Interface Water Evaporation Applications

Due to the rapid development of industry,water scarcity and pollution are profoundly affecting human production and life.In order to solve this kind of problems,clean-water technology has been developed rapidly.Among them,solar interface water evaporation as a green sustainable application technology has received a lot of attention from researchers.However,there are still some problems,such as low evaporation efficiency and complicated material preparation process.At the same time,due to the vapour escapes process of solar interface water evaporation,resulting in the concentration of various pollutants in the unevaporated water increases,which is more unfavourable to the environment.In order to solve these problems,in this paper,reduced graphene oxide（rGO）,sulphur（S）and copper sulphide(Cu_2-xS)ternary composites were prepared by laser and mixed with graphene oxide（GO）which has good adsorption capacity to get comprehensive purification of various pollutants in unevaporated water,and the following conclusions were summarised after experimental tests and analysis:（1）GO adsorbed with Cu²⁺was dispersed in thiourea solution and the rGO/S/Cu_2-xS composites were synthesized under laser irradiation using the photothermal effect of GO.It was verified that the possible cause of the synthesis was the hydrolysis of thiourea to produce H₂S,which reacted with Cu²⁺to produce Cu S.Due to the laser thermal effect,Cu S decomposed to produce S/Cu_2-xS nanocomposites.The solar interfacial water evaporation performance of the composites was tested,with evaporation rates up to 2.64 kg·m^-2·h^-1 under solar irradiation of1.0 k W·m^-2.Meanwhile,the composites showed good photocatalytic performance of rhodamine B（Rh B）solution.The Rh B removal ratio reached maximum at 79%for the composites under solar irradiation of 1.0 k W·m^-2.It is also bactericidal to Gram-negative Escherichia coli（E.coli）and Gram-positive Staphylococcus aureus（S.aureus）.（2）rGO/S/Cu_2-xS was mixed with GO with excellent ad·sorption properties and loaded onto melamine sponges（MS）for the purification of contaminants（dyes,bacteria,heavy metal ions）in unevaporated water from the process of solar interface evaporation water.With the synergistic effect of photothermal,photocatalytic and adsorption,the degradation rate of Rh B in the unevaporated water reached 79% at a light intensity of 1.0 k W·m^-2,and good evaporation performance of the solar interface water was maintained.Meanwhile,the co-blends showed significant removal effects on E.coli and S.aureus,and the removal of heavy metal ions reached over 99%.