TiO2 Nanoparticles and Nb2O5 Nanorods Immobilized rGO for Efficient Visible-Light Photocatalysis and Catalytic Reduction

In the present study, we demonstrated a new strategy to decorate TiO2 nanoparticles on the surface of Nb2O5 nanorods to obtain a unique TiO2/Nb2O5 nanocomposite (NC). In order to achieve a high catalytic activity, TiO2/Nb2O5 NC was dispersed and anchored over reduced graphene oxide (rGO). The ratio between rGO and TiO2/Nb2O5 NC was varied to obtain two types of rGO/TiO2/Nb2O5 composites i.e. Cat-A and Cat-B. Cat-A (rGO:TiO2/Nb2O5 similar to 1: 0.3 wt/wt) showed higher photo-catalytic degradation efficiency under visible light irradiation in comparison to Cat-B (rGO:TiO2/Nb2O5 similar to 1:0.6 wt/wt). In contrast, Cat-B showed enhanced catalytic activity for the reaction involving reduction of p-nitrophenol to p-amino phenol in the presence of NaBH4 as a reductant. The higher photocatalytic activity of Cat-A and catalytic reduction of Cat-B can be attributed to (i) high charge carrier mobility of rGO; (ii) strong acidity of crystal planes of Nb2O5 nanorods; and (iii) the synergistic effect of rGO and TiO2/Nb2O5 nanocomposites. [GRAPHICS] .

Automated summary

In this study, a new strategy was demonstrated to decorate TiO2 nanoparticles on the surface of Nb2O5 nanorods, resulting in a unique TiO2/Nb2O5 nanocomposite (NC). To achieve high catalytic activity, the TiO2/Nb2O5 NC was dispersed and anchored over reduced graphene oxide (rGO). Two types of rGO/TiO2/Nb2O5 composites, Cat-A and Cat-B, were obtained by varying the ratio between rGO and TiO2/Nb2O5 NC. Cat-A (rGO:TiO2/Nb2O5 similar to 1:0.3 wt/wt) showed higher photo-catalytic degradation efficiency under visible light irradiation compared to Cat-B (rGO:TiO2/Nb2O5 similar to 1:0.6 wt/wt). On the other hand, Cat-B exhibited enhanced catalytic activity for the reduction of p-nitrophenol to p-amino phenol in the presence of NaBH4 as a reductant. The higher photocatalytic activity of Cat-A and catalytic reduction of Cat-B can be attributed to factors such as the high charge carrier mobility of rGO, the strong acidity of crystal planes of Nb2O5 nanorods, and the synergistic effect of rGO and TiO2/Nb2O5 nanocomposites.