Defect induced electrocatalytic hydrogen properties of pentagonal PdX2 (X = S, Se)

Jingjing Li; Dan Liang; Gang Liu; Baonan Jia; Jingyu Cao; Jinbo Hao; Pengfei Lu

doi:10.1039/d1ra07466k

Defect induced electrocatalytic hydrogen properties of pentagonal PdX₂ (X = S, Se)

RSC Adv. 2021 Nov 30;11(61):38478-38485. doi: 10.1039/d1ra07466k. eCollection 2021 Nov 29.

Authors

Jingjing Li¹, Dan Liang¹, Gang Liu¹, Baonan Jia¹, Jingyu Cao¹, Jinbo Hao², Pengfei Lu¹

Affiliations

¹ State Key Laboratory of Information Photonics and Optical Communications, School of Electronic Engineering, Beijing University of Posts and Telecommunications Beijing 100876 China liangdan@bupt.edu.cn liu_g@126.com.
² School of Science, Xi'an University of Architecture and Technology Xi'an 710055 Shaanxi China.

Abstract

Searching for catalysts of hydrogen evolution reaction (HER) that can replace Pt is critical. Here, we investigated the HER electrocatalytic activity of pentagonal PdS₂ (penta-PdS₂) and PdSe₂ (penta-PdSe₂) by first-principles calculations. Three types of vacancies (V_S/Se, V_Pd, DV_S/Se) were constructed to activate the inert basal planes of PdS₂ and PdSe₂. The results show that S/Se and Pd vacancies significantly improve HER performance, and the Gibbs free energy (ΔG _H) of systems can be further regulated by vacancy concentration. Particularly, PdS₂ with 2.78% V_S, 50% V_Pd and PdSe₂ with 12.5% V_Se display the optimal ΔG _H value and the highest exchange current density. Further analysis of charge transfer and band structures were described that the introduce of vacancies efficiently regulates the electronic properties, resulting in the diminution of bandgap, and accelerates the charge transfer, thereby contributing to an enhanced electron environment for HER process. Our results provide a theoretical guidance for the applications of pentagonal transition-metal dichalcogenides as catalysts of hydrogen evolution reaction.