Hierarchical dessert plant-like CoNiO2 nanowires decoration on MoS2 nano-petals for enhanced bi-functional overall water splitting reactions

Abstract

To produce hydrogen, overall water splitting is the extremely effective method and their one of the key factors is the fabrication of bifunctional electrode materials with high catalytic activity, rotational design with a high active site, easy mass transfer, stability, and earth abundance. In this work, CoNiO2 nanowires (NWs)-embedded MoS2 hybrids were prepared using the hydrothermal synthesis method. The developed CoNiO2@MoS2 hybrid electrode achieved superior bifunctional catalytic activity with an overpotential of 43 mV and 220 mV for hydrogen evolution and oxygen evolution reactions, respectively, and more than 24 h span stability. Furthermore, the assembled CoNiO2@MoS2║CoNiO2@MoS2 electrocatalyst exhibited an overpotential of 1.47 V for overall splitting process at 10 mA cm−2, with improved electronic conductivity and stability. Density functional theory approximations revealed that the CoNiO2 NWs and MoS2 in the CoNiO2@MoS2 hybrid exhibited a strong interfacial contact, which enabled the preferable ΔGH⁎ and ΔGn values, thus significantly improving the electrocatalytic performance. The development of cobalt-based oxides with transition metal dichalcogenides-carrier bifunctional electrocatalysts will provide a novel approach to enhance overall water splitting.