Superior photothermal conversion performance of black titanium-based materials

The application of photothermal conversion technology in the fields of seawater desalination and wastewater treatment stands as a potent approach to alleviating the global water scarcity crisis. In this research, we have successfully synthesized black titanium-based photothermal conversion materials utilizing the aluminothermic reduction method. The experimental results demonstrate that the crafted black TiO₂ exhibits a notable overall solar energy absorptivity of 65.7% and a photothermal conversion efficiency of 87.5%. Notably, the black Magneli phase titanium oxide (Ti₄O₇ and Ti₅O₉), derived from nanorutile TiO₂, exhibits an even more impressive overall solar absorptivity of 83.4% and a photothermal conversion efficiency of 93.8%. Under a light intensity of 5 kW/m², this material achieves an evaporation rate of 4.4 kg m^-2·h^-1 and an evaporation efficiency of 63%, underscoring its vast potential for applications in wastewater purification and seawater desalination.