Department of Solid State Engineering, University of Chemistry and Technology, 166 28 Prague, Czech Republic.
Central Laboratories, University of Chemistry and Technology, 166 28 Prague, Czech Republic.
ACS Appl Mater Interfaces. 2023 Feb 1;15(4):5679-5686. doi: 10.1021/acsami.2c20261. Epub 2023 Jan 20.
Among 2D materials, transition-metal dichalcogenides (TMDCs) of group 5 metals recently have attracted substantial interest due to their superior electrocatalytic activity toward hydrogen evolution reaction (HER). However, a straightforward and efficient synthesis of the TMDCs which can be easily scaled up is missing. Herein, we report an innovative, simple, and scalable method for tantalum disulfide (TaS) synthesis, involving CS as a sulfurizing agent and TaO as a metal precursor. The structure of the created TaS flakes was analyzed by Raman, XRD, XPS, SEM, and HRTEM techniques. It was demonstrated that a tuning between 1T (metallic) and 3R (semiconductor) TaS phases can be accomplished by varying the reaction conditions. The created materials were tested for HER, and the electrocatalytic activity of both phases was significantly enhanced by electrochemical self-activation, up to that comparable with the Pt one. The final values of the Tafel slopes of activated TaS were found to be 35 and 43 mV/dec for 3R-TaS and 1T-TaS, respectively, with the corresponding overpotentials of 63 and 109 mV required to reach a current density of 10 mA/cm. We also investigated the mechanism of flake activation, which can be attributed to the changes in the flake morphology and surface chemistry. Our work provides a scalable and simple synthesis method to produce transition-metal sulfides which could replace the platinum catalyst in water splitting technology.
在二维材料中，最近五族过渡金属二卤化物（TMDCs）由于其对析氢反应（HER）的优异电催化活性而引起了极大的兴趣。然而，缺少一种能够简单高效合成 TMDCs 且易于扩大规模的方法。在此，我们报告了一种创新的、简单的、可扩展的合成二硫化钽（TaS）的方法，该方法使用 CS 作为硫化剂和 TaO 作为金属前体。通过拉曼、XRD、XPS、SEM 和 HRTEM 技术对所生成的 TaS 薄片的结构进行了分析。结果表明，通过改变反应条件可以实现 1T（金属）和 3R（半导体）TaS 相之间的调谐。所制备的材料被用于 HER 测试，两种相的电催化活性都通过电化学自激活得到了显著增强，达到了与 Pt 相当的水平。经电化学自激活后，3R-TaS 和 1T-TaS 的 Tafel 斜率分别为 35 和 43 mV/dec，达到 10 mA/cm^2 电流密度所需的过电势分别为 63 和 109 mV。我们还研究了薄片激活的机制，这可以归因于薄片形貌和表面化学的变化。我们的工作提供了一种可扩展且简单的合成方法，用于生产过渡金属硫化物，该方法可以替代水分解技术中的铂催化剂。
