Single-Atom Pt Anchored on Oxygen Vacancy of Monolayer Ti<sub>3</sub>C<sub>2</sub>T<sub><i>x</i></sub> for Superior Hydrogen Evolution.

Zhang, Jiangjiang; Wang, Erqing; Cui, Shiqiang; Yang, Shubin; Zou, Xiaolong; Gong, Yongji · Nano Lett · 2022

basic_science · Level V

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Abstract

Two-dimensional (2D) MXene-loaded single-atom (SA) catalysts have drawn increasing attention. SAs immobilized on oxygen vacancies (O<sub>V</sub>) of MXene are predicted to have excellent catalytic performance; however, they have not yet been realized experimentally. Here Pt SAs immobilized on the O<sub>V</sub> of monolayer Ti<sub>3</sub>C<sub>2</sub>T<sub><i>x</i></sub> flakes are constructed by a rapid thermal shock technique under a H<sub>2</sub> atmosphere. The resultant Ti<sub>3</sub>C<sub>2</sub>T<sub><i>x</i></sub>-Pt<sub>SA</sub> catalyst exhibits excellent hydrogen evolution reaction (HER) performance, including a small overpotential of 38 mV at 10 mA cm<sup>-2</sup>, a high mass activity of 23.21 A mg<sub>Pt</sub><sup>-1</sup>, and a large turnover frequency of 23.45 s<sup>-1</sup> at an overpotential of 100 mV. Furthermore, density functional theory calculations demonstrate that anchoring the Pt SA on the O<sub>V</sub> of Ti<sub>3</sub>C<sub>2</sub>T<sub><i>x</i></sub> 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.