High-Density Dual-Structure Single-Atom Pt Electrocatalyst for Efficient Hydrogen Evolution and Multimodal Sensing.

Chu, Tianshu; Wang, Guiying; Zhang, Xiangyu; Jia, Yanyan; Dai, Sheng; Liu, Xinzhi; Zhang, Li; Yang, Xuan et al. · Nano Lett · 2024

basic_science · Level V

Where this comes from

Abstract

Herein, we report a high-density dual-structure single-atom catalyst (SAC) by creating a large number of vacancies of O and Ti in two-dimensional (2D) Ti<sub>3</sub>C<sub>2</sub> to immobilize Pt atoms (SA Pt-Ti<sub>3</sub>C<sub>2</sub>). The SA Pt-Ti<sub>3</sub>C<sub>2</sub> showed excellent performance toward the pH-universal electrochemical hydrogen evolution reaction (HER) and multimodal sensing. For HER catalysis, compared to the commercial 20 wt % Pt/C, the Pt mass activities of SA Pt-Ti<sub>3</sub>C<sub>2</sub> at the overpotentials of ∼30 and 110 mV in acid and alkaline media are 45 and 34 times higher, respectively. More importantly, during the alkaline HER process, an interesting synergetic effect between Pt-C and Pt-Ti sites that dominated the Volmer and Heyrovsky steps, respectively, was revealed. Moreover, the SA Pt-Ti<sub>3</sub>C<sub>2</sub> catalyst exhibited high sensitivity (0.62-2.65 μA μM<sup>-1</sup>) and fast response properties for the multimodal identifications of ascorbic acid, dopamine, uric acid, and nitric oxide under the assistance of machine learning.