Zhao Feifan, Sheng Hexuan, Sun Qipei, Wang Jingnan, Liu Qian, Hu Zhifu, He Bing, Wang Yang, Li Zhen, Liu Xueqin
Faculty of Materials Science and Chemistry, China University of Geosciences, Wuhan 430074, China.
Faculty of Materials Science and Chemistry, China University of Geosciences, Wuhan 430074, China.
J Colloid Interface Sci. 2022 Sep;621:267-274. doi: 10.1016/j.jcis.2022.04.052. Epub 2022 Apr 14.
Infrared light absorbed by semiconductors hardly contributes to the solar energy conversion due to its low photon energy. Herein, photothermal effect activated by infrared part of solar light is introduced to promote the photoelectrochemical (PEC) water splitting of photoanodes. Narrow band-gap semiconductor BiS is deposited on the surface of WO nanosheets, exhibiting a broad-spectral response. In addition to the enhanced density of photo-generated electrons, significant temperature elevation is observed for the BiS/WO composite photoanode under the illumination of infrared part of solar light because of the photothermal conversion property of BiS. The moderately enhanced temperature accelerates charge carrier migration and finally increases the efficiency of solar energy conversion. With the assistance of photothermal effect, a remarkable photocurrent density of 4.05 mA cm at 1.23 V vs. reversible reference electrode (V) is achieved by BiS/WO composite photoanode, over 880% higher than that of the pristine WO. The introduction of photothermal effect activated by infrared light provides general and robust strategy to promote the PEC performance of photoanodes.
由于光子能量较低，半导体吸收的红外光对太阳能转换几乎没有贡献。在此，引入由太阳光的红外部分激活的光热效应来促进光阳极的光电化学（PEC）水分解。窄带隙半导体BiS沉积在WO纳米片表面，表现出宽光谱响应。除了光生电子密度增强外，由于BiS的光热转换特性，在太阳光红外部分的照射下，BiS/WO复合光阳极的温度显著升高。适度升高的温度加速了电荷载流子的迁移，最终提高了太阳能转换效率。在光热效应的辅助下，BiS/WO复合光阳极在1.23 V相对于可逆参比电极（V）时实现了4.05 mA cm的显著光电流密度，比原始WO高出880%以上。由红外光激活的光热效应的引入为提高光阳极的PEC性能提供了通用且强大的策略。
