Facile template-free fabrication of different micro/nanostructured In2O3 for photocatalytic H2 production from glucose solution

Indium oxide (In2O3) is a promising semiconductor used for various photocatalytic reactions, yet the green and template-free synthesizing the different micro/nanostructured In2O3 with tunable morphology is still full of challenge. In this study, the three morphological In2O3 with 3D micro-cubelike (In2O3-MC), 3D micro-ricelike (In2O3-MR), and 2D nano-platelike (In2O3-NP) were successfully fabricated through a facile hydrothermal strategy without any organic template additives. Owing to the enlarged specific surface area, promoted charge migration rate and suitable surface oxygen vacancies density, the unique 3D ricelike In2O3-MR exhibited the best photocatalytic H2 generation activity from biomass glucose solution, which was 1.9-fold and 1.7-fold higher than that of In2O3-MC and In2O3-NP under the same experimental conditions. In addition, the optimum photoactivity of In2O3-MR was achieved under the alkaline environment with pH = 11 and 1.0 wt% Pt cocatalyst loading, which was better than the most of previously reported In2O3-based photocatalysts. Simultaneously, the possible photocatalytic mechanism for solar H2 evolution from glucose solution was also discussed. Our work will bring about potential application in preparation of other photocatalysts with controlling morphology for renewable photocatalysis.