Nanospheres and nanorods structured Fe_2O_3 and Fe_(2-x)Ga_xO_3 photocatalysts for visible-light mediated (λ ≥ 420 nm) H_2S decomposition and H_2 generation

摘要

This article reports our investigation on H_2 generation from visible light (λ ≥ 420 nm) photodecomposition of H_2S by nanomaterial catalysts, α-Fe_2O_3 and its chemically modified Fe_(2-x)Ga_xO_3 (Ga substitution at x = 0.6, FeGaO_+3-I and x = 1.0, FeGaO_3-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 Fe_2O_3 and nanosticksanorods for both FeGaO_3-I, and FeGaO_3-II. In H_2 generation, Fe_2O_3 and FeGaO_3-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 FeGaO_3-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 H_2S by nanostructured photocatalysts involving morphology dependent activity enhancement.