Construction of ternary heterojunction photocatalyst CuCl(OH)/In/InO for boosted photocatalytic CO reduction performance.

The photocatalytic conversion of CO and HO into useful chemicals or fuels over semiconductor photocatalysts is regarded as a promising technology to address the problems of global warming and energy exhaustion. However, inefficient photo-absorption and slow charge dynamics limit the CO photoreduction efficiency. Here, a ternary heterojunction photocatalyst, CuCl(OH)/In/InO (Cu H IO), with an intimate interface is obtained a hydrogen chemical reduction approach followed by hydrolysis reaction, where In species can be produced on the surface of InO from the hydrogen chemical reaction with a calcining temperature of over 500 °C. Cu H IO exhibits enhanced photocatalytic activity for CO conversion compared to pristine InO, InO with In species (H IO), and CuCl(OH)/InO (Cu IO). In the absence of sacrificial agent or cocatalyst, the yield rates of CO and CH over Cu H IO are 4.36 and 1.09 μmol g h, which are 8.38-fold and 18-fold that of pristine InO (0.52 and 0.06 μmol g h), respectively. The photocatalytic performance enhancement of Cu H IO results from the construction of the ternary heterojunction, with synchronous improvement in the photoresponse and charge separation of InO. Moreover, the possible CO reduction pathway over Cu H IO has also been investigated and proposed. This work provides an important strategy for developing a high-efficiency heterojunction photocatalyst system for solar fuel generation.