Enhanced electrocatalytic hydrogen evolution reaction by injection of photogenerated electrons in Ag/WS2 nanohybrids

In renewable energies devices, effective water splitting by electrocatalysis holds a lot of promise for generating hydrogen fuel. Typically, designing commercially feasible, effective, and stable electrocatalysts to reduce activation potential barriers is essential to applying high-performance water splitting. Herein, we report an active catalyst based on photosensitive Ag/WS2 hybrids for effective and rapid hydrogen evolution reaction. Ag/WS2 hybrids with optimised material proportions demonstrate the over potential as low as -170 mV vs RHE in acidic medium and -180 mV in basic medium at -10 mA/cm(2) for hydrogen evolution reaction which is far lower than that of pristine materials. We demonstrate that the injection of photogenerated electrons under excitation of Ag localized surface plasmon resonance (LSPR) as well as owing to exciton generation in WS2 nanosheets can further reduce the over potential upto -140 mV vs RHE at -10 mA/cm(2 )in acidic medium and -150 mV vs RHE in basic medium and significantly enhances the current density. This research advocates the promising path for activation of intrinsic electrocatalytic activities of semiconducting materials to encourage use of renewable sources of energy.

Automated summary

An active catalyst based on photosensitive Ag/WS2 hybrids has been developed for effective and rapid hydrogen evolution with low over potential. The injection of photogenerated electrons and exciton generation in WS2 nanosheets significantly reduces the over potential and enhances current density. This research advocates activating intrinsic electrocatalytic activities of semiconducting materials to promote the use of renewable energy sources.