Edge-dominated hydrogen evolution reactions in ultra-narrow MoS 2 nanoribbon arrays

• Published in: Journal of materials chemistry. A, Materials for energy and sustainability Materials for energy and sustainability, 2023-07, Vol.11 (29), p.15802-15810
• Main Authors: Chen, Ding-Rui, Muthu, Jeyavelan, Guo, Xing-You, Chin, Hao-Ting, Lin, You-Chen, Haider, Golam, Ting, Chu-Chi, Kalbáč, Martin, Hofmann, Mario, Hsieh, Ya-Ping
• Format: Article
• Language: English
• ISSN: 2050-7488; 2050-7496
• DOI: 10.1039/D3TA01573D

Future energy generation and storage requirements emphasize the importance of high-performance electrocatalysis. MoS 2 edges exhibit ideal energetics for hydrogen evolution reactions (HERs) if challenges in their kinetics are addressed. Herein, we investigate the emergence of edge-dominated electrochemical reaction kinetics in ultra-narrow MoS 2 nanoribbons. A templated subtractive patterning process (TSPP) served as a powerful platform that yields large arrays of MoS 2 nanoribbons. Nanoribbons with widths below 30 nm exhibit significantly increased reaction kinetics, as evidenced by a ∼200-fold enhanced turn-over frequency, an 18-fold increased exchange current density, and a 38% decreased Tafel slope. These improvements are due to increased charge transfer efficiency from the basal plane toward the edge sites. Photo-electrocatalytic measurements and carrier transport simulations reveal the impact of suppressed band bending in nanoribbons below the depletion width toward achieving edge-dominated HER. Our results demonstrate the potential of confinement in electrocatalysis and provide a universal route toward nanoribbon-enhanced electrochemistry.