Orbital adjustment and photothermal effect promoted overall water splitting for POM derived MoO2 electrocatalyst

Abstract

MoO2 is an environmentally friendly electrocatalyst for overall water splitting. Due to weak adsorption towards intermediate products, such as adsorbed H(H*) in hydrogen evolution reaction (HER) and different oxygen species (*OH, *O, *OOH) in oxygen evolution reaction (OER), the activity of MoO2 requires further improvement. Elevation of O 2p orbital and d band center in MoO2 can enhance its adsorption towards above intermediate products. To achieve this goal, Co is doped in MoO2.Obtained Co-MoO2 only requires89 and 253 mV to gain 10 mA·cm-2current in HER and OER. Excellent photothermal effect of Co-MoO2 facilitates thermal harvesting from sun light. Under solar irradiation, temperature of Co-MoO2 enhances, which improves overall water splitting performance greatly. Besides temperature increasing, light irradiation also induces structural change and raises d band center. This also decreases water splitting voltage. In solar irradiation induced overall water splitting, Co-MoO2 also shows good stability.