Ma Lei, Sun Tao, Cai Hua, Zhou Zhi-Quan, Sun Jian, Lu Ming
Department of Optical Science and Engineering, and Shanghai Ultra-Precision Optical Manufacturing Engineering Center, Fudan University, Shanghai 200433, China.
J Chem Phys. 2015 Aug 28;143(8):084706. doi: 10.1063/1.4929910.
Surface plasmon (SP)-enhanced ultraviolet and visible photocatalytic activities of SrTiO3 (STO) are observed after incorporating Ag nanoparticles (Ag-NPs) on STO surfaces. A two-step excitation model is proposed to explain the SP-enhanced photocatalysis. The point of the model is that an electron at the valence band of STO is first excited onto the Fermi level of Ag-NP by the SP field generated on the Ag-NP, and then injected into the conduction band of STO from the SP band, leaving a hole at the valence band of STO. A full redox catalytic reaction at the surface of STO is then available. For Ag-NP incorporated STO, up-converted and inter-band photoluminescence emissions of STO are observed, and nonlinear evolutions of photocatalytic activity with illumination light powers are found. Furthermore, near infrared photocatalysis is detected. These results support the proposed model.
在SrTiO₃（STO）表面掺入银纳米颗粒（Ag-NPs）后，观察到表面等离子体（SP）增强了STO的紫外和可见光光催化活性。提出了一个两步激发模型来解释SP增强的光催化作用。该模型的要点是，STO价带中的一个电子首先被Ag-NP上产生的SP场激发到Ag-NP的费米能级，然后从SP带注入到STO的导带，在STO的价带留下一个空穴。然后在STO表面发生完整的氧化还原催化反应。对于掺入Ag-NP的STO，观察到了STO的上转换和带间光致发光发射，并且发现光催化活性随光照功率呈非线性变化。此外，还检测到了近红外光催化作用。这些结果支持了所提出的模型。
