Nanosheets of MoSe2@M (M = Pd and Rh) function as widespread pH tolerable hydrogen evolution catalyst

Abstract

In this present study we have developed method for the synthesis of MoSe2 nanosheets following a simple hydrothermal technique. Palladium (Pd) and rhodium (Rh) nanoparticles were decorated on the surface of MoSe2 following a simple wet-chemical route. Pd and Rh nanoparticles decorated MoSe2 were applied for hydrogen evolution reaction (HER) in different pH conditions like acidic (0.5 M H2SO4), neutral (pH-7 buffer) and in alkaline (1 M KOH) medium and 3.5 wt% of saline water. Pd and Rh decorated MoSe2 show efficient activity towards HER irrespective of the applied electrolyte. In 0.5 M H2SO4, MoSe2 can produce 10 mA/cm2 current density with applied potential of −0.256 V vs. RHE. Rh decorated MoSe2 shows more shift in the onset potential. Upon applied potential of −0.192 V vs. RHE, MoSe2/Rh can produce 10 mA/cm2 current density. MoSe2/Rh is electrocatalytically more active than MoSe2/Pd which is established from the calculated electrochemically active surface area (ECSA) value. Significantly lower (47 mV/decade) Tafel value is observed for MoSe2/Rh in 0.5 M H2SO4 which indicates the superior activity. MoSe2/Rh is more stable in neutral and alkaline medium compared to acidic medium and it can retain its own activity even after continuous 12 h reaction.