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

Abstract

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.