Ga-La5Ti2Cu0.9Ag0.1O7S5(Ga-LTCA), an oxysulfide photocatalyst, can act as a hydrogen evolution photocatalyst in Z-scheme water splitting systems in conjunction with an oxygen evolution photocatalyst (OEP) under visible light irradiation up to 700 nm. However, the overall efficiency is strongly limited by the low activity of Ga-LTCA. The present work demonstrates a drastic improvement in the H2evolution activity of Ga-LTCA after loading small Rh cocatalyst particles exhibiting uniform dispersion and intimate contact with the photocatalyst. Using this system, an apparent quantum yield (AQY) of 11.2 ± 0.9% at 420 nm was obtained for H2evolution from an aqueous Na2S-Na2SO3solution, this being the highest value yet reported for a sacrificial H2evolution reaction using an oxysulfide photocatalyst. Following modification with a Cr2O3layer, efficient Z-scheme water splitting was also accomplished using the cocatalyst-loaded Ga-LTCA in combination with H+/Cs+/PtOx/WO3as the OEP, with an improved AQY of 2.4% at 420 nm.
ASJC Scopus subject areas
- Renewable Energy, Sustainability and the Environment
- Materials Science(all)