摘要： 为了提高光生载流子分离效率，本文利用简单两步法将核壳结构Au@SiO2纳米颗粒负载到TiO2纳米棒阵列。对得到的Au@SiO2/TiO2光阳极进行了X射线衍射（XRD）、扫描电子显微镜（SEM）、透射电子显微镜（TEM）和光电化学等表征。和纯TiO2纳米棒薄膜相比，Au@SiO2/TiO2薄膜的光电化学分解水性能得到了明显提高，在0.8 V的偏压下，380 nm处的光电转换效率从31%提高至37%。这可由Au@SiO2的表面等离子共振效应解释。表面等离子共振效应可产生强度分布不均的电磁场，可导致TiO2纳米棒表面产生的载流子很容易分离。这种利用表面等离子效应促使载流子分离的改性方式提供了一种开发高效太阳能光电化学分解水半导体光电极的有前途的方法。
关键词： 二氧化钛；载流子分离；金属等离子共振；光阳极

SHEN Shaohua^1,*， CHEN Jianan^2,

 

Abstract： To improve the separation efficiency of photo-induced charge carries, Au@SiO2 nanoparticles with core-shell structure were loaded onto the surface of TiO2 nanorods grown on FTO substrate by a facile two-step process. The resulted Au@SiO2/TiO2 photoanodes were characterized by X-ray diffraction (XRD), Scanning electron microscopy (SEM), Transmission electron microscopy (TEM) as well as photoelectrochemical measurements. When compared to pristine TiO2 nanorod film, the Au@SiO2/TiO2 films showed remarkable enhancement in photoelectrochemical water splitting, with incident photon to current conversion efficiency (IPCE) increased from 31% to 37% at 380 nm and 0.8 V vs. SCE. This could be interpreted by the effect of metallic surface plasmon resonance of Au@SiO2 nanoparticles, which would generate an intense electromagnetic field with spatially non-homogenous distributed intensity. As a result, the charge carriers generated in the near surface region of TiO2 nanorods could be easily separated. This modification method based on the effect of metallic surface plasmon resonance for promoted charge carrier separation provides a promising way to develop semiconductor photoelectrodes with high solar water splitting performance.
Keywords： titanium oxide; charge carrier separation; metallic plasmon resonance; photoanode

作者简介： SHEN Shaohua, (1982-), Male, Associate professor, Solar water splitting.