Pt-loading reverses the photocatalytic activity order of anatase TiO₂ {0 0 1} and {0 1 0} facets for photoreduction of CO₂ to CH₄

详细信息    查看全文

• 作者：Jin Mao ; Liqun Ye ; Kan Li ; Xiaohu Zhang ; Jinyan Liu ; Tianyou Peng ; Ling Zan
• 关键词：Photoreduction of CO2 ; TiO2 {0  ; 0  ; 1} and {0  ; 1  ; 0} facets ; Pt-loading ; Photocatalytic activity
• 刊名：Applied Catalysis B: Environmental
• 出版年：2014
• 出版时间：January, 2014
• 年：2014
• 卷：144
• 期：Complete
• 页码：855-862
• 全文大小：2995 K

文摘

It is well known that different crystal facets of TiO₂ have different surface electronic and atomic structures, which can influence the photocatalytic performance, and appropriate noble metal-loading usually improves the photocatalytic activity. Herein we demonstrate that Pt-loading can reverse the photocatalytic activity order of anatase TiO₂ {0 0 1} facets (TiO₂-0 0 1) and {0 1 0} facets (TiO₂-0 1 0) for the photoreduction of CO₂ to CH₄. This new phenomenon was discussed on the bases of the experimental data including attenuated total reflectance Fourier transform infrared (ATR-IR) spectra, CO₂ temperature programmed desorption (CO₂-TPD) curves, transmission electron microscopy (TEM) images and time-resolved photoluminescence (PL) spectra. It is found that the higher photocatalytic CO₂ reduction activity of TiO₂-0 1 0 without Pt-loading can be attributed to its larger CO₂ adsorbed amount and longer charge lifetime as compared with TiO₂-0 0 1, while the Pt nanoparticles loaded on TiO₂-0 0 1 can more efficiently enhance the photoinduced carrier separation efficiency than that on TiO₂-0 1 0, and therefore resulting in a photoactivity higher than the Pt-loaded TiO₂-0 0 1. The above results provide an important indication about the effects of Pt-loading on the photocatalytic CO₂ reduction activity of anatase TiO₂ with different exposed facets, and shed light on the fabrication of novel nanostructured photocatalysts through morphological control for high conversion efficiency in the CO₂ resource utilization.