Synergistic Integration of MXene and Metal-Organic Frameworks for Enhanced Electrocatalytic Hydrogen Evolution in an Alkaline Environment

Abstract

The development of transition metal (TM) catalysts to replace precious metals has garnered increasing interest. Specifically, platinum (Pt)-based catalysts have been extensively investigated for their electrochemical performance in hydrogen evolution reaction (HER), which offer a clean means of producing hydrogen fuel without carbon emissions. However, the reliance on Pt-based catalysts has hindered the progress of HER development. Therefore, researchers have explored metal-organic frameworks (MOFs) as a substitute for noble Pt-based catalysts to address this issue. Nevertheless, the low electroconductivity of pure MOFs restricts their application in electrochemical fields. To overcome this limitation, MXenes have emerged as a promising two-dimensional (2D) material for coupling with MOFs to create an electrocatalyst with high electrical conductivity, a large surface area, and a tunable structure. In this study, we report the synthesis of a Ti3C2Tx (MXene) nanosheet-encapsulated MOFs catalyst (Ti3C2Tx@ZIF-8) with high activity and a low cost by encapsulating the precursor with ZIF-8 for HER in alkaline media. The catalyst exhibits an overpotential of only 507 mV at 20 mA/cm2 and a low Tafel slope value of 77 mV/dec. Additionally, cyclic voltammetry (CV) indicates an electrochemical active surface area (ECSA) of 122.5 cm2, and chronopotentiometry demonstrates the stable nature of the catalyst over 20 h without any significant changes in the overpotential value. The excellent electrochemical properties of Ti3C2Tx@ZIF-8 suggest its potential as a promising material for energy conversion applications.