Single-Atom Pt Anchored on Oxygen Vacancy of Monolayer TiCT for Superior Hydrogen Evolution.

Two-dimensional (2D) MXene-loaded single-atom (SA) catalysts have drawn increasing attention. SAs immobilized on oxygen vacancies (O) of MXene are predicted to have excellent catalytic performance; however, they have not yet been realized experimentally. Here Pt SAs immobilized on the O of monolayer TiCT flakes are constructed by a rapid thermal shock technique under a H atmosphere. The resultant TiCT-Pt catalyst exhibits excellent hydrogen evolution reaction (HER) performance, including a small overpotential of 38 mV at 10 mA cm, a high mass activity of 23.21 A mg, and a large turnover frequency of 23.45 s at an overpotential of 100 mV. Furthermore, density functional theory calculations demonstrate that anchoring the Pt SA on the O of TiCT helps to decrease the binding energy and the hybridization strength between H atoms and the supports, contributing to rapid hydrogen adsorption-desorption kinetics and high activity for the HER.