Novel photosensitive Ni-doped TiO2 nanocomposites: visible light photocatalytic treatment of Rhodamine B

TiO₂ photocatalytic materials with different nickel doping contents were successfully prepared by using the sol–gel method. Through a variety of advanced characterization techniques such as X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray analysis (EDAX), ultraviolet–visible absorption spectroscopy (UV–Vis), and Fourier transform infrared spectroscopy (FTIR), Photoluminescence (PL), BET surface area, the structural and performance of the prepared catalysts were comprehensively characterized. Meanwhile, organic dyes were selected as the target degradable substances, and the photocatalytic efficiency was systematically tested. Using the batch experiment method, the photocatalytic degradation activity of Ni-doped TiO₂ (Ni-TiO₂) on Rhodamine B(Rh-B) dye was deeply investigated. The experimental results showed that when the Ni doping content was 1%, Ni-TiO₂ exhibited the highest degradation rate, reaching 98.22%. To clarify the intrinsic mechanism of this excellent performance, the catalyst was analyzed in depth, and it was found that the doped samples could generate more electron–hole pairs. Compared with pure TiO₂, the average effective mass of photogenerated electrons and holes in Ni-TiO₂ was smaller. The smaller effective mass significantly promoted carrier migration and effectively inhibited the recombination of carriers. In addition, through density functional theory (DFT) calculations, the above experimental results were further verified, providing a theoretical basis for the mechanism of improving photocatalytic performance.