To study the impact of La and Mo coexistence in pure Nb2O5 nanostructure for the improvement of photocatalytic hydrogen production and verification by theoretical analysis

Abstract

The present study conducted the synthesis of pure (Nb₂O₅) and a series of La–Mo co-doped Nb₂O₅ nanoparticles (NPs) to degrade the mixture of (MB + RhB) dyes and produce hydrogen (H₂) gas. We employed a straightforward and effective hydrothermal technique to produce both undoped Nb₂O₅ and a series of La–Mo co-doped Nb₂O₅ NPs. We investigated the morphological, structural, optical, and spectral characteristics using the SEM, XRD, EDS, UV–Vis, PL, BET, FT-IR, and PEC analysis. The ionic radii of the dopant La and Mo are comparable to those of Nb₂O₅, which has a significant impact on decreasing the rate at which photo-generated electron/hole pairs recombine. This results in band gap reductions of up to 2.73 eV for direct transitions. We assessed the photocatalytic properties of the NPs by exposing the dye mixture to visible light. The increased surface-to-volume ratio resulting from the smaller NPs leads to a higher number of active adsorption sites, thereby improving the catalyst's photocatalytic activity and H₂ production. This optimal sample has outstanding electrical conductivity, according to the EIS test. It is notable that the La_0.04Mo_0.04Nb_1.92O₅ catalyst demonstrates optimal outcomes due to its ability to achieve a maximum degradation of 98 % within 56 min and produce more hydrogen (1 $5.2mmol/gh$). We assessed the stability of the optimized NPs by implementing recycling and trapping experiments. The exceptional photocatalytic performance of as-synthesized La_0.04Mo_0.04Nb_1.92O₅ NPs illustrates their potential applications in wastewater treatment and H₂ production by water splitting.