MXene-containing composite electrodes for hydrogen evolution: Material design aspects and approaches for electrode fabrication

• Published in: International journal of hydrogen energy Vol. 46; no. 21; pp. 11636 - 11651
• Main Authors: Sergiienko, Sergii A., Lopes, Daniela V., Constantinescu, Gabriel, Ferro, Marta C., Shchaerban, Nataliya D., Tursunov, Obid B., Shkepu, Viacheslav I., Pazniak, Hanna, Tabachkova, Nataliya Yu, Castellón, Enrique Rodríguez, Frade, Jorge R., Kovalevsky, Andrei V.
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 23.03.2021; Elsevier
• Subjects: Electrocatalysts; Engineering Sciences; Hydrogen evolution; Materials; MXene; Nickel; Nickel; Hydrogen evolution; Electrocatalysts; MXene; MXene ; Nickel ; Hydrogen evolution ; Electrocatalysts
• ISSN: 0360-3199; 1879-3487
• DOI: 10.1016/j.ijhydene.2021.01.041

This work explores the possibilities for the processing of Ni- and Ti3C2Tx (T = OH, O) MXene-containing composite electrodes, by co-pressing and plastic deformation or by etching of the electrodes prepared directly by self-propagation high-temperature synthesis (SHS). Various material design approaches were also explored. In order to tune the Ti3C2 interlayer distance in Ti3C2Al MAX phase, an introduction of additional Al to form Ti3C2Alz materials with z > 1 was attempted. Self-propagation high-temperature synthesis of powder mixtures with extra Ni and Al content (e.g. Ni:Ti:Al:C = 1:2:3:1) resulted in SHS products containing Ti3C2Alz z > 1 material and Ni–Al alloys. Further etching of these products in 10M NaOH allowed the direct formation of electrodes with active surface containing Ti3C2Tx (T = OH, O) MXene- and Raney nickel-containing composites. The electrochemical studies were focused on hydrogen evolution and showed the potential for boosting the electrochemical reaction in Ni and MXene-containing composite electrodes, especially at high current densities. The guidelines for the processing of such electrodes under fluorine-free conditions are proposed and discussed. •Ti3C2Alz (z > 1) MAX phases containing Al excess were synthesized.•The composites based on Ni–Al alloy and Ti3C2Alz phase (z > 1) were obtained.•Processing of MXene-containing electrodes under F-free conditions is demonstrated.•Etching in alkaline medium forms active MXene- and Ni-containing surface layer.•MXene- and Ni-containing electrodes show enhanced activity towards the HER.