Synthesis, characterization and electrocatalytic study of Pd supported on CeO₂–N, S-rGO composite towards hydrogen and oxygen evolution reaction

The sustainable production of hydrogen and oxygen through the electrolysis of water requires the development of an efficient electrocatalyst. In this work, we report the electrocatalytic activity of Pd nanoparticles dispersed on CeO₂/N, S-rGO (where N, S-rGO represents nitrogen and sulfur-doped reduced graphene oxide). The CeO₂/N, S-rGO and Pd nanoparticles were synthesized by hydrothermal and chemical reduction methods, respectively. Electrochemical measurements towards hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) show a high electrocatalytic activity of the catalyst. Among the synthesized electrocatalysts Pd/CeO₂/N, S-rGO exhibits lower overpotential (75 mV and 240 mV) at 10 mA/cm² and lower Tafel slope value (44 mV/dec and 42 mV/dec) for HER and OER, respectively. The chronoamperometric and linear sweep voltammetry (LSV) of the electrocatalyst shows a negligible decrease in the current density for twelve hours and a minor change in the polarization curve after 10,000 cycles, respectively. The high electrocatalytic activity and superior stability of the synthesized electrocatalyst could be attributed to the synergetic effect between Pd nanoparticles and CeO₂/N, S-rGO support. This work demonstrates a facile way to develop effective and stable electrocatalysts by exploiting the Pd/Metal oxide interface.