Efficient overall water splitting of a suspended photocatalyst boosted by metal-support interaction

Strong metal-support interaction (SMSI) has been widely discussed for activity promotion of heterogeneous catalysis, but the effect of SMSI on photocatalysis remains unclear. Here, we employ bismuth vanadate (BiVO4)-supported iridium (denoted as Ir/BVO) as a model photocatalyst to observe highly dispersed iridium overlayers as well as moderate SMSI effect between Ir and BiVO4. It is revealed that charge separation on the Ir/BVO can be remarkably promoted by the SMSI effect. Together with the right distribution of dual cocatalysts (Ir and IrO2) achieved by a simple photoinduction, the water oxidation activity on optimal Ir/BVO is about 75 times higher than that on pristine BVO. Finally, we construct an effective redox-driven Z-scheme overall water splitting system with a benchmark apparent quantum efficiency of 16.9% under visible light irradiation of 420 ± 10 nm at room temperature. Our work extends the application of SMSI to photocatalysis to provide an alternative way of promoting photocatalytic activity.