Visible-Light-Driven Efficient Hydrogen Production from CdS NanoRods Anchored with Co-catalysts Based on Transition Metal Alloy Nanosheets of NiPd, NiZn, and NiPdZn

Investigation of new catalysts to improve artificial photosynthesis efficiencies is an absolute need concerning energy demands and environmental issues. In the present study, nanosheets of NiPd, NiZn, and NiPdZn metal alloys, synthesized at the toluene water interface, have been employed as co-catalysts for hydrogen evolution from water in the presence of CdS nanorods (NRs) as a photosensitizer. Anchoring of alloy nanosheets with CdS NRs resulted in exceptional enhancement in hydrogen evolution activity. Interestingly earth abundant cost-effective CdS/NiZn photocatalyst showed higher hydrogen evolution reaction (HER) activity than comparatively precious photocatalyst CdS/NiPd. Trimetallic alloy nanosheets of NiPdZn further exhibited superior HER activity concerning bimetallic alloys, NiZn and NiPd. An enhancement of 21 times in the hydrogen evolution activity of CdS has been achieved by optimum loading of NiPdZn. Hydrogen yields of 21347.3 mu mol h(-1) g(-1) (AQY 11.35%) and 53361.3 mu mol h(-1) g(-1) (AQY = 28%) have been obtained from CdS/NiPdZn catalyst under respectively. Noteworthy to mention is that photocatalysts based on these alloy nanosheets alkaline and acidic conditions, only exhibit hydrogen evolution activities but also show exceptional stability in alkaline as well as in acidic medium. Spectroscopic and photoelectrochemical measurements are carried out to understand the hydrogen evolution activities.