Difunctional hierarchical Co_xP QDs-MoS_2@Ni_3S_2/NF nanostructure as advanced electrocatalyst for water electrolysis

摘要

A Co_xP QDs-MoS_2 nanosheets@Ni_3S_2 nanoarrays/NF with electrocatalytic overall water splitting is fabricated via a simple hydrothermal-electrodeposition method. There, the MoS_2@Ni_3S_2/NF is prepared by a hydrothermal method on the surface of NF, and subsequently the Co_xP QDs are deposited by an elec-trodeposition method on the surface of MoS_2 nanosheets. As demonstrated, the as-prepared Co_xP QDs-MoS_2@Ni_3S_2/NF presents low overpotentials of 54 mV(HER) at 10 mA cm~(-2) and 207 mV(OER) at 100 mA cm~(-2) in 1.0 M KOH, and exhibits a decent overall water splitting performance, including the over-potential of 1.39 V(vs RHE) at 10 mA cm~(-2) which can be mainly ascribed to the hierarchical nanostructure can increase MoS_2 nanosheets and Co_xP QDs effi-ciently for increasing the HER/OER active sites. Additionally, the extra HER active sites of edge S atoms from MoS_2 nanosheets, the extra OER active sites induce by the presence of Ni~(3+)/Ni~(2+) and Co~(3+)/Co~(2+)mixed state, and low overpotential of Ni_3S_2, MoS_2 and Co_xP QDs are also important reasons.