Photocatalytic overall water splitting over an open-framework gallium borate loaded with various cocatalysts

•Photocatalytic water splitting ability of Ga-PKU-1 was systematically studied.•Various cocatalysts were loaded, including CoOx, RuOx, Pt, Au, NiOx and Ag.•Overall water splitting into stoichiometric H2 and O2 was achieved.•Ga-PKU-1 remained stable after three cycles of photocatalytic experiments.

We present a systematic investigation on the photocatalytic ability of an open-framework gallium borate, Ga-PKU-1. It was reported to be intrinsically active for water reduction or oxidation, however, acquiring sacrificial reagents. Here the loading of CoOx, RuOx, Pt, Au, NiOx and Ag as cocatalysts greatly enhanced the catalytic activity, which eventually lead to overall water splitting into stoichiometric H2 (28.4 μmol/h/g) and O2 (14.5 μmol/h/g) for 1 wt.% RuOx–1 wt.% Pt loaded Ga-PKU-1. After three cycles of photocatalytic water splitting experiments, it gave the constant H2 evolution rate with no degradation of the catalyst.

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