Reduced Graphene Oxide/O-MWCNT Hybrids Functionalized with p‑Phenylenediamine as High-Performance MoS₂ Electrocatalyst Support for Hydrogen Evolution Reaction

Abstract

Efficient hydrogen evolution through water splitting at low overpotentials is crucial to develop renewable energy technology, which depends on the design of efficient and durable electrocatalysts composed of earth-abundant elements. Herein, a highly and stable electrocatalyst for hydrogen evolution reaction (HER) has been developed on the basis of MoS₂ on p-phenylenediamine (PPD)-functionalized reduced graphene oxide/O-containing carbon nanotubes (rGO/O-MWCNT) hybrids via facile and green hydrothermal process. Among the prepared catalysts, the optimized MoS₂/rGO/PPD/O-MWCNT with nanosized and highly dispersed MoS₂ sheets provides a large amount of available edge sites and the improved electron transfer in 3D conductive networks. It exhibits excellent HER activity with a low overpotential of 90 mV and large current density of 47.6 mA·cm^–2 at 200 mV, as well as excellent stability in an acidic medium. The Tafel slope of 48 mV·dec^–1 reveals the Volmer–Heyrovsky mechanism for HER. Thus, this work paves a potential pathway for designing efficient MoS₂-based electrocatalysts for HER by functionalized conductive substrates