In-situ synthesis of crystalline Ag-Nb2O5 nanobelt clusters with enhanced solar photo-electrochemical performance for splitting water

The crystalline hexagonal Nb2O5 (H-Nb2O5) nanobelt clusters dominantly exposed (- 110) facet are firstly synthesized by a hydrothermal topological reaction with a precursor of fiber-like K2Nb2O6 center dot H2O. The structure and morphology of samples obtained at different temperatures and times are investigated. There are two steps in the synthesis process. One is the acid-exchanging reaction transforming into amorphous phase protonated niobate (HNO), and the other is dehydration reaction transforming into H-Nb2O5, and simultaneous dissolution reaction which forms nanobelt cluster morphology from the fiber- like particle. The formation mechanism of H-Nb2O5 nanobelt clusters has been proposed in detail. After photo-reduced reaction between the H-Nb2O5 nanobelt clusters and AgNO3 solution, the dominantly exposed (- 110) facet of H-Nb2O5 nanobelt is homogeneously covered by Ag nanoparticles. The photo-electrochemical performance of the obtained H-Nb2O5 nanobelt clusters and Ag deposited H-Nb2O5 (Ag-Nb2O5) nanobelt clusters as photocatalysts are evaluated by splitting water under simulated sunlight illumination, and the generated photocurrent of Ag-Nb2O5 sample is 10.73 mu A, which is 535 times that of the H-Nb2O5 sample. The results demonstrate that the Ag-Nb2O5 nanobelt clusters have a high photo-electrochemical performance as well as good sunlight photoelectric conversion efficiency.