Au-25-Loaded BaLa4Ti4O15 Water-Splitting Photocatalyst with Enhanced Activity and Durability Produced Using New Chromium Oxide Shell Formation Method

作者：Kurashige Wataru; Kumazawa Rina; Ishii Daiki; Hayashi Rui; Niihori Yoshiki; Hossain Sakiat; Nair Lakshmi V; Takayama Tomoaki; Iwase Akihide; Yamazoe Seiji; Tsukuda Tatsuya; Kudo Akihiko; Negishi Yuichi^*

来源：Journal of Physical Chemistry C, 2018, 122(25): 13669-13681.

DOI：10.1021/acs.jpcc.8b00151

We report herein remarkable improvement of activity and stability of an Au-25-loaded BaLa4Ti4O15 water splitting photocatalyst. We first examined the influence of refining the gold cocatalyst on the individual reactions over the BaLa4Ti4O15 photocatalyst in this water-splitting system. The results revealed that refining the gold cocatalyst accelerates not only the hydrogen generation reaction, but also oxygen photoreduction reaction, which suppresses the H-2 generation via photoreduction of protons. This finding suggests that photocatalytic activity will be enhanced if the O-2 photo reduction reaction can be selectively suppressed by covering Au-25 with a Cr2O3 shell which is impermeable to O-2 but permeable to H+. Then, we developed new method for the formation of the Cr2O3 shell onto Au-25. Our method utilizes the strong metal-support interaction between them. Water-splitting photoactivity of Au-25-BaLa4Ti4O15 was improved by 19 times under an optimized coverage of the Cr2O3 shell. The Cr2O3 shell also elongated the lifetime of the photocatalysts by preventing the agglomeration of Au-25 cocatalysts.

• 出版日期2018-6-28