To achieve sustainable
production of H2 at ambient temperature, highly active
and stable electrocatalysts are the key to water splitting technology
commercialization for hydrogen and oxygen production to replace Pt
and IrO2 catalysts. Herein, a modified interface of palladium
(Pd) and reduced graphene oxide (RGO)-supported molybdenum disulfide
(MoS2) prepared by the solvothermal followed by chemical
reduction method is established, in which abundant interfaces are
formed. The phase structure, composition, chemical coupling, and morphology
of the two-dimensional nanostructures are established by X-ray diffraction
(XRD), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS),
and transmission electron microscopy, respectively. A structural phase
transformation in MoS2 is observed from trigonal (2H) to
octahedral (1T) by virtue of Pd addition, which is well established
from XRD, Raman, and XPS studies. For oxygen evolution reaction (OER)
and hydrogen evolution reaction (HER), the RGO/MoS2/Pd
(RMoS2Pd) catalyst exhibits extremely low overpotential
(245 mV for OER and 86 mV for HER) to achieve benchmark current density,
with small values of Tafel slope (42 mV dec–1 for
OER and 35.9 mV dec–1 for HER) and charge transfer
resistance. The quantitative study shows the hydrogen production rate
of RMoS2Pd of 335 μmol h–1 with
excellent stability in alkaline medium, which is superior to MoS2, RMoS2, and MoS2Pd. The improved performance
of RMoS2Pd is attributed to the combined synergetic effect
of 1T MoS2, sulfur vacancy, and conducting RGO sheet, which
efficiently accelerate the overall electrochemical water splitting.