Impact of the PtO loading on mesoporous TiO₂ nanoparticles for enhanced photodegradation of Imazapyr herbicide under simulated solar light

The removal of the commonly used herbicides is essential for environmental remediation. In this study, mesoporous TiO₂ photocatalysts modified with PtO were synthetized by the template-assisted scheme to develop highly effective materials for the elimination of Imazapyr herbicide under visible-light preservation. The effect of the PtO loading was investigated, and the xPtO-TiO₂ materials were deeply considered by N₂ physisorption, XRD, HRTEM, FTIR, DRS UV-Vis, Raman, XPS, PL and photocurrent measurements. Total Imazapyr photodegradation was archived on mesoporous TiO₂ photocatalysts loaded with 0.6 and 0.8 wt% of PtO. The optimized xPtO-TiO₂ photocatalyst degrades the Imazapyr under solar light more efficiently than the pure TiO₂ and the commercial Degussa P25 (photoefficiency of 35%, 1%, and 0.5%, respectively). The improvement in the photoefficiency of the xPtO-TiO₂ photocatalysts respect to the pure TiO₂ was associated to the cooperative effect between PtO and TiO₂ nanoparticles leading to a lessening in the energy gap and lower recombination of excited electron-hole pairs. The optimized 0.6PtO-TiO₂ photocatalyst demonstrated to be stable and recyclable after up to five consecutive photocatalytic runs. Therefore, it can be a potential candidate for the significant mineralization of Imazapyr herbicide under solar light irradiation.