Self-floating V/N co-doped TiO2/diatomite hybrid granule with enhanced visible-light-responsive photoactivity and reusability

Abstract

Powdery photocatalyst has long been studied, however its several drawbacks such as low recyclability in suspension system hinder its application in real water remediation. This paper provides an alternative method to solve the above problem. TiO2 nanoparticles were co-doped by vanadium and nitrogen, and then immobilized onto natural mineral diatomite via sol-gel method. The as-synthesized powder was granulated to produce self-floating granule catalyst (V/N co-doped TiO2/diatomite hybrid granule, denoted as VN-TDHG). The synergy between V and N dopants, as well as diatomite and TiO2 were investigated. The photoactivity of VN-TDHG was investigated via the degradation towards an organic dye Rhodamine B (RhB) under visible light irradiation, and then the optimal co-doping amount and catalyst dosage were determined. The optimal granule catalyst presented the removal rate of RhB as 92.1% during 150 min of reaction time. Moreover, VN-TDHG could simply be collected from the surface of water matrix, presenting good stability and reusability after 5 repetitions.