Upadhyay Shrish Nath, Pakhira Srimanta
Department of Metallurgy Engineering and Materials Science (MEMS), Indian Institute of Technology Indore (IIT Indore), Khandwa Road, Simrol, Indore-453552, MP, India.
Department of Physics, Indian Institute of Technology Indore, Khandwa Road, Simrol, Indore-453552, MP, India.
Phys Chem Chem Phys. 2022 Sep 28;24(37):22823-22844. doi: 10.1039/d2cp00924b.
Two-dimensional transition metal dichalcogenides (TMDs) are a new family of 2D materials with features that make them appealing for potential applications in nanomaterials science and engineering. Recently, these 2D TMDs have attracted significant research interest because of the abundant choice of materials with diverse and tunable electronic, optical, chemical, and electrocatalytic properties. Although, the edges of the 2D TMDs show excellent electrocatalytic performance, their basal plane (001) is inert, which hinders their industrial applications for electrocatalysis. Transition metal/chalcogen atom vacancies or doping with some other foreign atoms may be a remedy to activate the inert basal plane. Here, we have computationally designed 2D monolayer MoSe and studied its electronic properties with electrocatalytic activities. A Pt-atom has been doped in the pristine 2D MoSe (, Pt-MoSe) to activate the inert basal plane resulting in a zero band gap. This study reveals that the Pt-MoSe is an excellent bifunctional electrocatalyst for both the hydrogen evolution reaction (HER) and oxygen reduction reaction (ORR) with the aid of first priciples-based hybrid density functional theory (DFT). The periodic hybrid DFT method has been applied to compute the electronic properties of both the pristine MoSe and Pt-MoSe. To determine both the HER and ORR mechanisms on the surface of the Pt-MoSe material, non-periodic DFT calculation has been performed by considering a molecular Pt-MoSe cluster model. The present study shows that the 2D Pt-MoSe follows the Volmer-Heyrovsky mechanism for the HER with energy barriers of about 9.29 kcal mol and 10.55 kcal mol during the H˙-migration and Heyrovsky reactions. The ORR is achieved by a four-electron transfer mechanism with the formation of two transition energy barriers of about 14.94 kcal mol and 11.10 kcal mol, respectively. The lower energy barriers and high turnover frequency during the reactions expose that the Pt-MoSe can be adopted as an efficient bifunctional electrocatalyst for both the HER and ORR. The present studies demonstrate that the exceptional HER and ORR activity and stability performance shown by the MoSe electrocatalyst can be enhanced by Pt-doping, opening a promising concept for the sensible design of high-performance catalysts for H production and O reduction.
二维过渡金属二硫属化物（TMDs）是一类新型二维材料，其特性使其在纳米材料科学与工程的潜在应用中颇具吸引力。近来，这些二维TMDs因其丰富多样且可调控的电子、光学、化学及电催化性质的材料选择，吸引了大量研究关注。尽管二维TMDs的边缘展现出优异的电催化性能，但其基面（001）是惰性的，这阻碍了它们在电催化领域的工业应用。过渡金属/硫属原子空位或掺杂其他外来原子可能是激活惰性基面的一种解决方法。在此，我们通过计算设计了二维单层MoSe，并研究了其具有电催化活性的电子性质。在原始的二维MoSe（，Pt-MoSe）中掺杂了一个Pt原子以激活惰性基面，从而产生零带隙。这项研究表明，借助基于第一性原理的杂化密度泛函理论（DFT），Pt-MoSe是用于析氢反应（HER）和氧还原反应（ORR）的优异双功能电催化剂。已应用周期性杂化DFT方法来计算原始MoSe和Pt-MoSe的电子性质。为确定Pt-MoSe材料表面的HER和ORR机理，通过考虑分子Pt-MoSe簇模型进行了非周期性DFT计算。本研究表明，二维Pt-MoSe在HER过程中遵循Volmer-Heyrovsky机理，在H˙迁移和Heyrovsky反应期间的能垒分别约为9.29 kcal mol和10.55 kcal mol。ORR通过四电子转移机理实现，分别形成约14.94 kcal mol和11.10 kcal mol的两个过渡能垒。反应过程中较低的能垒和高周转频率表明，Pt-MoSe可作为HER和ORR的高效双功能电催化剂。本研究表明，通过Pt掺杂可以增强MoSe电催化剂所展现出的优异HER和ORR活性及稳定性性能，为合理设计用于制氢和氧还原的高性能催化剂开辟了一个有前景的概念。
