2D Nitride MXenes for Electrochemical Energy Storage and Conversion

Abdoulaye Djire from Texas A&M University

The large-scale shift towards renewable energy technology requires the ability to reliably convert and store electrochemical energy. This technology is still limited in terms of performance, cost, and/or ease of utilization. In recent years, two-dimensional (2D) materials have been explored as low-cost, high-performing catalysts and electrodes for the reliable conversion and storage of electrochemical energy. Of these 2D materials, a special class of carbides and nitrides, known as MXenes, have gained popularity due to their high tunability, conductivity, and high surface area-to-volume ratio. From these MXenes, the carbide form has been the most vastly studied, but the nitride MXene has been theorized to perform better due to their higher electronic conductivity. In this presentation, I will present on the oxygen-assisted molten salt fluoride etching synthesis technique developed in my lab to produce phase-pure nitride MXenes. Along with this, I will provide evidence of the enhanced capabilities of the nitride MXenes compared to carbides, sulfides, and oxides, when applied in the nitrogen reduction reaction (NRR), hydrogen evolution reaction (HER), carbon dioxide reduction reaction (CO2RR), and supercapacitor applications. In each of these fields, the enhanced performance is investigated using in-situ/operando spectroelectrochemical techniques. I will wrap up by discussing the future directions in the field of MXenes that require further attention for the advancement of 2D materials in electrochemical energy storage and conversion systems.