XPS valence band observable light-responsive system for photocatalytic acid Red114 dye decomposition using a ZnO-Cu₂O...

ZnO-Cu₂O composites were made as photocatalysts in a range of different amounts using an easy, cheap, and environment-friendly coprecipitation method due to their superior visible light activity to remove pollutants from the surrounding atmosphere. X-ray diffraction and Fourier transform infrared spectroscopy (FT-IR) have demonstrated that ZnO-Cu₂O catalysts are made of highly pure hexagonal ZnO and cubic Cu₂O. X-ray photoelectron spectroscopy has confirmed that there is a substantial interaction between the two phases of the resultant catalyst. The optical characterizations of the synthesized ZnO-Cu₂O composite were done via UV-vis reflectance spectroscopy. Due to the doping on ZnO, the absorption range of the ZnO-Cu₂O catalyst is shifted from the ultraviolet to the visible region due to diffuse reflection. The degradation efficiency is affected by the Ratio of ZnO: Cu₂O and ZnO-Cu₂O composite with a proportion of 90:10 exhibited the most prominent photocatalytic activity on Acid Red 114, with a pseudo-first-order rate constant of 0.05032 min^-1 that was 6 and 11 times greater than those of ZnO and Cu₂O, respectively. The maximum degradation efficiency is 97 %. The enhanced photocatalytic activity of the composite is caused by the synergistic interaction of ZnO and Cu₂O, which improves visible light absorption by lowering band gap energy and decreasing the rate at which the electron-hole pairs recombine. The scavenging experiment confirmed that hydroxyl radical was the dominant species for the photodegradation of Acid Red 114. Notably, the recycling test demonstrated the ZnO-Cu₂O photocatalyst was highly stable and recyclable. These results suggest that the ZnO-Cu₂O mix might be able to clean up environmental pollutants when it meets visible light.