Design of carbon loaded porous TiO2 foams by the hydrothermal-assisted annealing carbonization of fruit residue for solar-driven water evaporation

摘要

Solar-dirven water evaporation is an effective way to utilize solar energy for the fresh water production. In this paper, we constructed a hybrid photothermal conversion material including porous TiO2 foams as the water molecule transfer layer and carbon as the photothermal sensitizer. The amorphous TiO2 porous layer was prepared by the anodization of Ti foam, and then carbon materials were deposited on the surface of TiO2 layers by the hydrothermal-assisted annealing carbonization of fruit (cherry, grape, orange and apple) residue. The investigation indicated that the TiO2 substrate prepared with anodization voltage of 30 V showed the excellent microstructure and photothermal conversion efficiency, and the carbon produced from grape residue had the high evaporation rate of 1.42 kg m(-2) h(-1) and photothermal conversion efficiency of 59.43% under 1.5 sun irradiation (150 kW/m(2)). The influence of irradiation power intensity on the water evaporation was also explored, and the photothermal membrane also showed high evaporation efficiency of seawater, and the evaporation rate and photothermal conversion efficiency nearly maintained the stable value, showing superstability after 12 irradiation cycles. Based on our experimental data, the design strategy of hybrid photothermal membranes would provide effective guidance for photothermal materials in applications of seawater desalination and wastewater treatment.