| Popis: |
Two-dimensional (2D) carbide and nitride MXenes possess properties that are desirable for a broad range of electrocatalytic applications including hydrogen evolution reaction (HER). These properties include high surface area, hydrophilicity, heterogeneity of redox-active transition metals, and tunable surface functionalities allowing for low HER overpotentials. In this presentation, I will report on the -O functionalization of Ti3CNTx (Tx = -O, -F, -OH) upon the application of external potential for improved HER performance and show that the active sites for HER on this MXene catalyst are located primarily on the O functional groups. The overpotential for the Ti3CN improves by 350 mV upon in-situ -O functionalization and reaches -0.46 V vs. RHE at a current density of 10 mA cm-2. Structural and electrochemical characterization results showed that the functionalized Ti3CNTx MXene catalyst is structural and electrochemically stable. Further insights into the mechanism of HER were provided by in-situ/operando Raman spectroelectrochemistry and the results will be presented. Ultimately, these findings provide a path forward to tuning the electrocatalytic activity of MXenes and related electrocatalysts for water splitting. |
