Nanospheres and nanorods structured Fe2O3 and Fe2-xGaxO3 photocatalysts for visible-light mediated (λ ≥ 420 nm) H2S decomposition and H2 generation

This article reports our investigation on H-2 generation from visible light (lambda >= 420 nm) photodecomposition of H2S by nanomaterial catalysts, alpha-Fe2O3 and its chemically modified Fe2-xGaxO3 (Ga substitution at x = 0.6, FeGaO3-I and x = 1.0, FeGaO3-II). Simple template-free hydrothermal technique was employed to synthesize the three photocatalysts. XRD study reveals rhombohedral nanocrystalline structure and FESEM shows nanospheres morphology for Fe2O3 and nanosticks/nanorods for both FeGaO3-I, and FeGaO3-II. In H-2 generation, Fe2O3 and FeGaO3-II perform moderate and almost same activities in the fresh and used conditions (quantum yield, QY = 6.0-6.8% at 550 nm). Contrarily, fresh FeGaO3-I exhibits a greater activity (11.2% QY) and the activity is further enhanced (QY = 15.3%) on regeneration and reuse. The intricacy, as resolved by XRD and FESEM, appears to take place through morphology transformation. The present work, thus, successfully demonstrates H-2 generation from H2S by nanostructured photocatalysts involving morphology dependent activity enhancement. (c) 2009 Professor T. Nejat Veziroglu. Published by Elsevier Ltd. All rights reserved.