Promotion of MXene (Ti3C2Tx) as a robust electrocatalyst for oxygen evolution reaction via active sites of ZIF-67-In situ mechanism investigations

Developing a robust and highly efficient electrocatalyst for the oxygen evolution reaction (OER) is required, due to its sluggish mechanism and high overpotential. Here, we present the Ti3C2Tx and ZIF-67 composites (MXene/ZIF-67) for an efficient OER. The MXene/ZIF-67_1:10 exhibits an overpotential of 366 mV, which is better than MXene (548 mV) and RuO2 (395 mV). Moreover, it shows improved electrochemical stability at 20 mA$cm- 2 with only a 0.2% increase in potential after 5 h, while RuO2 with an overpotential loss of 3.5%. After an increase in the current density of 10-20 mA cm-2 the potential increase by 7.4%, while in RuO2 by 25.3%. To reveal the observed performance, the composite's robustness and explain each component's role. Moreover, a detailed OER mechanism is discussed. It was realized via in situ Raman microscopy and XRD which allowed the revealing of the active species responsible for boosting OER.(c) 2023 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.

Automated summary

In this study, a composite of Ti3C2Tx and ZIF-67 (MXene/ZIF-67) is developed as an efficient electrocatalyst for the oxygen evolution reaction (OER). The composite exhibits improved electrochemical stability and a lower overpotential compared to MXene and RuO2. In addition, the study reveals the mechanism and role of each component in enhancing the OER performance.