Wang Hao, Chen Ding-Rui, Lin You-Chen, Lin Po-Han, Chang Jui-Teng, Muthu Jeyavelan, Hofmann Mario, Hsieh Ya-Ping
Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei 10617, Taiwan.
Department of Physics, National Taiwan University, Taipei 10617, Taiwan.
ACS Nano. 2024 Jul 16;18(30):19828-35. doi: 10.1021/acsnano.4c06341.
The edges of 2D materials have emerged as promising electrochemical catalyst systems, yet their performance still lags behind that of noble metals. Here, we demonstrate the potential of oriented electric fields (OEFs) to enhance the electrochemical activity of 2D materials edges. By atomically engineering the edge of a fluorographene/graphene/MoS heterojunction nanoribbon, strong and localized OEFs were realized as confirmed by simulations and spatially resolved spectroscopy. The observed fringing OEF results in an enhancement of the heterogeneous charge transfer rate between the edge and the electrolyte by 2 orders of magnitude according to impedance spectroscopy. Ab initio calculations indicate a field-induced decrease in the reactant adsorption energy as the origin of this improvement. We apply the OEF-enhanced edge reactivity to hydrogen evolution reactions (HER) and observe a significantly enhanced electrochemical performance, as evidenced by a 30% decrease in Tafel slope and a 3-fold enhanced turnover frequency. Our findings demonstrate the potential of OEFs for tailoring the catalytic properties of 2D material edges toward future complex reactions.
二维材料的边缘已成为很有前景的电化学催化剂体系，但其性能仍落后于贵金属。在此，我们展示了定向电场（OEFs）增强二维材料边缘电化学活性的潜力。通过对氟石墨烯/石墨烯/MoS异质结纳米带的边缘进行原子工程设计，经模拟和空间分辨光谱证实实现了强且局域的OEFs。根据阻抗谱，观察到的边缘电场导致边缘与电解质之间的异质电荷转移速率提高了2个数量级。从头算计算表明，反应物吸附能的场致降低是这种改善的根源。我们将OEF增强的边缘反应性应用于析氢反应（HER），并观察到电化学性能显著增强，塔菲尔斜率降低30%和周转频率提高3倍证明了这一点。我们的研究结果证明了OEFs在为未来复杂反应定制二维材料边缘催化性能方面的潜力。
