Submerged Photosynthesis of TiO2-CuO Hetero-nanoparticles and their Multiple Applications for Water Issues under Solar Light

Environmental challenges, encompassing issues like agricultural ammonia discharge, industrial organic dye misuse, and high environmental polluted water evaporation, demanded urgent attention. In response, we proposed a method for synthesizing TiO2-CuO hetero-nanoparticles capable of different environmental protection commands. Submerged Photosynthesis of Crystallites (SPSC) was adopted due to its simplicity and eco-friendliness. Hetero-nanoparticles with varying Cu-Ti ratios were prepared, characterized, and assessed. CuO dispersion within TiO2 proved consistently even. Increasing Cu content increased Cu-Ti ratio until reaching an upper limit. All nanoparticle samples demonstrated excellent solar light absorption. Combining solar illumination and electrochemical techniques synergistically boosted pollutant degradation. The nanoparticle with a Cu-Ti ratio of 0.17 exhibited optimal photo-electrochemical degradation, enhancing efficiency by 150% under solar light compared to darkness. It also outperformed solar light alone by 32% and electrochemistry alone by 2% in RhB degradation. Furthermore, it enhanced water evaporation rate under solar light. The nanoparticle with a Cu-Ti ratio of 0.52 was the highest water evaporation rate, increasing up to 104% compared to the control group. We discussed the mechanisms underlying fabrication and degradation, elucidating the observed performance. In conclusion, our research underscored the potential of TiO2-CuO hetero-nanoparticles for solar-assisted solutions to different environmental issues, highlighting their environmental applicability.