Visible light induced photocatalytic overall water splitting over micro-SiC driven by the Z-scheme system

• Overall water splitting has been achieved over micro-SiC composited with WO3.
• The stoichiometric amounts of H2 and O2 are obtained in this work.
• Quantum yield goes to 0.021% at 420 nm under optimum condition.
• Reduction is demonstrated to be the rate determining step in this system.

We present the micro-sized SiC powder applying to overall water splitting under visible light irradiation without adding any sacrificial compounds. The stoichiometric amounts of H2 and O2 in 2:1 were obtained when using WO3 nanoparticle and Pt-loaded micro-SiC grains as the O2 and H2 evolution photocatalysts, respectively. The relatively low efficiency step for splitting water reaction is the H+ reduction in the solution. Under optimal condition, the apparent quantum efficiency reaches up to 0.021% at 420 nm. Our results provide a method to enhance the photocatalytic activity of micro-sized SiC powder for overall water splitting using solar energy.

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