Underpotential deposition promoting low Pt loading on MoO2/MoS2 heterostructure towards wide pH green hydrogen evolution

Abstract

The preparation of ultrafine and uniform Pt catalysts with low content to promote hydrogen evolution reaction (HER) remains a great challenge due to the thermodynamical instability. In addition, the naturalization of water splitting and hydrogen adsorption ability also requires deliberate design. Here, we report an underpotential deposition (UPD)-replacement route for the low-content Pt loading on the MoO2/MoS2 heterostructure (Pt@MoO2/MoS2). The Pt@MoO2/MoS2 containing uniform and ultrafine Pt nanocluster exhibits improved HER activity because the Pt and MoO2/MoS2 synergistically regulate the water dissociation and hydrogen adsorption/desorption. Moreover, the strong electron interaction between Pt and MoO2/MoS2 owing to the metal-support effect contributes to the acceleration of electron exchange. As verification, the Pt@MoO2/MoS2 only needs 12 (alkaline) and 42 mV (acidic) to reach the current density of 10 mA cm−2, even superior to the Pt/C benchmark. The Pt@MoO2/MoS2 also shows favourable long-term stability thanks to the metal-support effect. This work not only demonstrates a promising approach to fabricating high effective electrocatalyst by the complementation of the adsorption ability of intermediates, but it also provides a universal method for the preparation of single-, bi- and multimetallic cluster catalysts for series of reactions.