Ultrastable MXene@Pt/SWCNTs' Nanocatalysts for Hydrogen Evolution Reaction

Abstract

Developing nano-or atom-scale Pt-based electrocatalysts for hydrogen evolution reaction (HER) is of considerable importance to mitigate the issues associated with low abundance of Pt. Here, a protocol for constructing a hierarchical Pt-MXene-single-walled carbon nanotubes' (SWCNTs) heterostructure for HER catalysts is presented. In the heterostructure, highly active nano/atom-scale metallic Pt is immobilized on Ti 3 C 2 T x MXene flakes (MXene@Pt) that are connected with conductive SWCNTs' network. The hierarchical heterostructure is constructed by filtrating a mixed colloidal suspension containing MXene@Pt and SWCNTs. Taking the advantages of the hydrophilicity and reducibility of MXene, the MXene@Pt colloidal suspension is prepared by spontaneously reducing Pt cations into metallic Pt without additional reductants or post-treatments. The so-fabricated hierarchical HER catalysts, in the form of membrane, show high stability during 800 h operation, a high volume current density of up to 230 mA cm −3 at −50 mV versus reversible hydrogen electrode (RHE) and a low overpotential of −62 mV versus RHE at the current density of −10 mA cm −2. This solution-processed strategy offers a simple, efficient, yet scalable approach to construct stable and efficient HER catalysts. Given the properties and the structure-activity relationships of the hierarchical Pt-MXene-SWCNTs' heterostructure, other MXenes probably show greater promise in HER electrocatalysis.

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