A binary dumbbell visible light driven photocatalyst for simultaneous hydrogen production with the selective oxidation of benzyl alcohol to benzaldehyde.

Photocatalytic H production with selective oxidation of organic moieties in an aqueous medium is a fascinating research area. However, the rational design of photocatalysts and their photocatalytic performance are still inadequate. In this work, we efficiently synthesized the MoS tipped CdS nanowires (NWs) photocatalyst using soft templates via the two-step hydrothermal method for efficient H production with selective oxidation of benzyl alcohol (BO) under visible light illumination. The optimized MoS tipped CdS NWs (20 % MoS) photocatalyst exhibits the highest photocatalytic H production efficiency of 13.55 mmol g h with 99 % selective oxidation of BO, which was 42.34 and 2.21 times greater photocatalytic performance than that of pristine CdS NWs and MoS/CdS NWs, respectively. The directional loading of MoS at the tips of CdS NWs (as compared to nondirectional MoS at CdS NWs) is the key factor towards superior H production with 99 % selective oxidation of BO and has an inhibitory effect on the photo corrosion of pristine CdS NWs. Therefore, the amazing enhancement in the photocatalytic performance and selectivity of optimized MoS tipped CdS NWs (20 % MoS) photocatalyst is due to the spatial separation of their photoexcited charge carriers through the Schottky junction. Moreover, the unique structure of the MoS flower at the tip of 1D CdS NWs offers separate active sites for adsorption and surface reactions such as H production at the MoS flower (confirmed by Pt photo deposition) and subsequently the selective oxidation of BO at the stem of CdS NWs. This rational design of a photocatalyst could be an inspiring work for the further development of an efficient photocatalytic system for H production with selective oxidation of BO (a strategy of mashing two potatoes with one fork).