A new layer perovskites Pb2Ga2Nb2O10 and RbPb2Nb2O7: An efficient visible light driven photocatalysts to hydrogen generation

We report here the novel approach to synthesis of layer perovskite photocatalysts, Pb2Ga2Nb2O10 and RbPb2Nb2O7 using solid state route (SSR) and molten salt synthesis (MSS) method. The reported modified MSS method has advantage over conventional SSR method for uniform particle size, well-defined crystal structure, controlled morphology and stoichiometry vis-a-vis photocatalysis. The structural study was performed using X-ray difractometry (XRD) and computation based on density functional theory (DFT). The simulation study showed that both the compounds belong to the Ruddlesden-Popper phase (A'(2)A(n-1)B(n)O(3n+1); n = 2 or 3). The surface morphology of the materials was studied using field emission scanning electron microscope (FESEM) and high resolution transmission electron microscope (HRTEM). The average particles size of perovskites Pb2Ga2Nb2O10 and RbPb2Nb2O7 was in the range 20-40 and 70-90 nm respectively. The efficacy of these materials was studied to particle size and morphology as a visible light driven photocatalyst for the hydrogen generation from H2S. Electronic band structure with DOS has also been performed for both the materials. Being a stable single-phase ternary-layered oxide perovskites and band gap (2.75 eV) in visible domain, they may have potential applications in electronic devices as well. (C) 2008 International Association for Hydrogen Energy. Published by Elsevier Ltd. All rights reserved.