Understanding the Structural and Electronic Effect of Zr4+-Doped KNb(Zr)O3 Perovskite for Enhanced Photoactivity: A Combined Experimental and Computational Study

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• 作者：Indranil Mondal ; Malladi SrikanthKancharlapalli Srinivasu ; Yarasi Soujanya ; Ujjwal Pal
• 刊名：Journal of Physical Chemistry C
• 出版年：2017
• 出版时间：February 9, 2017
• 年：2017
• 卷：121
• 期：5
• 页码：2597-2604
• 全文大小：523K
• ISSN：1932-7455

文摘

Herein, for the first time we report the synthesis of a series of compositionally tunable Zr-doped novel KNb(Zr)O₃ perovskites using green and facile methodology and their superior photocatalytic activities toward photoinduced hydrogen production and dye degradation. The substitutional doping of Zr(IV) in place of Nb(V) leads to a decrease in the electronic band gap by inclusion of a new acceptor level near the valence band. The results on the optimally doped perovskite for the photocatalytic hydrogen evolution reaction reveal that the 20 mol % Zr-doped KNb(Zr)O₃ is 13 times more efficient as compared to the pristine KNbO₃ in terms of rate of H₂ evolution. The same nanocomposite is shown to exhibit 12-fold greater photocatalytic efficiency for degradation of Rhodamine B (RhB) (up to 83% after 210 min) than pure KNbO_3. Density functional theory calculations are carried out to understand the Zr doping effect on the electronic structure as well as the surface hydrogen evolution reaction. Overall, an optimized combination of morphology vs photophysical features synergizes the photocatalytic activity of these newly developed perovskites.