Electronic Structure and Optical Properties of Nb2O5 Photo-Catalyst Calculated By Density Functional Method

Recently, there has been attempts to increase the photo-catalytic activities of Nb₂O₅ with the addition of carbon modifications [1-4]. It has been proposed that carbonate species on the modified Nb₂O₅ act as surface sensitizer, which extends the photo-catalytically active region of Nb₂O₅ into the visible range [1-3]. Experiments have shown the photo-catalytic activity of these carbon-modified Nb₂O₅ structures are higher than of non-carbon-modified Nb₂O₅ and carbon-modified meso-porous TiO₂ [1]. These carbon-modified Nb₂O₅ structures are promising candidates for photo-catalytic water splitting and more research is needed to understand these materials at the atomic scale. Here, we propose a DFT study of carbon-modified Nb₂O₅ (001) plane. The aim of this study is to determine the source of activity gain through electronic structure calculations. First, ground state, density of states, energy band structures, and optical properties of carbon-modified Nb₂O₅ are calculated. The electronic interaction between carbon and Nb₂O₅ will also be examined to determine its contribution to modify adsorption of intermediate species such as O₂, H₂, and OH. Band edge potentials and band gaps as calculated indicate the potential for driving the water cleavage reaction using solar energy. These results as presented point to a set of design guidelines for optimizations of photo-catalytic activity of Nb₂O₅.

  References

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