N/Fe/Zn co-doped TiO2 loaded on basalt fiber with enhanced photocatalytic activity for organic pollutant degradation

Abstract

To avoid the loss of catalytic material powder, a loaded catalytic material of TiO₂ with basalt fiber as the carrier (TiO₂@BF) was synthesized by an improved sol–gel method. The TiO₂@BF was doped with different contents of N, Fe and Zn elements and was used to degrade rhodamine B (RhB) under ultraviolet light. The physical characterization analysis indicated that the co-doping of the N, Fe and Zn elements had the effects of reducing grain size, increasing sample surface area, and narrowing the electronic band gap. The electronic band gap of nitrogen–iron–zinc co-doped TiO₂@BF (N/Fe/Zn_TiO₂@BF) was 2.80 eV, which was narrower than that of TiO₂@BF (3.11 eV). The degradation efficiency of RhB with N/Fe/Zn_TiO₂@BF as a photocatalyst was 4.3 times that of TiO₂@BF and its photocatalytic reaction was a first-order kinetic reaction. Quenching experiments suggested that the reactive species mainly include photoinduced holes (h⁺), superoxide radicals (˙O₂⁻) and hydroxyl radicals (˙OH). In brief, this study provides a prospective loaded catalytic material and routine for the degradation of organic contaminants in water by a photocatalytic process.