Article ID Journal Published Year Pages File Type
1275571 International Journal of Hydrogen Energy 2013 8 Pages PDF
Abstract

Potassium niobate (KNbO3) submicro-crystals with cubic and orthorhombic phases were hydrothermally prepared and characterized by powder X-ray diffraction, micro-Raman spectroscopy, Fourier transform infrared spectroscopy, nitrogen adsorption–desorption, diffuse reflectance UV–visible spectroscopy, X-ray photoelectron spectroscopy, scanning electron microscopy, and high-resolution transmission electron microscopy. The photocatalytic performance of the as-prepared KNbO3 samples was evaluated toward H2 generation from an aqueous methanol solution under UV. The surface area-normalized rate of H2 production over submicro-cubes with cubic phase is two times larger than that of submicro-rods with orthorhombic phase. In addition, both cubic and orthorhombic KNbO3 submicro-crystals showed much higher reactivity than commercial KNbO3 bulk-like powders. The underlying mechanism was discussed in terms of crystal structure and electronic structure. The results from this study are potentially applicable to a range of perovskites useful in water splitting as well as other areas of heterogeneous photocatalysis.

► KNbO3 sub-microsized crystals with different phases were hydrothermally prepared. ► The rate of H2 production follows cubic > orthorhombic ≫ commercial KNbO3. ► Crystal structure and electronic structure play a key role in water splitting. ► Our results are potentially applicable to a range of perovskite photocatalysts.

Related Topics
Physical Sciences and Engineering Chemistry Electrochemistry
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