Controlled synthesis of transition metal dichalcogenide (TMD) monolayers with unusual crystal phases has attracted increasing attention due to their promising applications in electrocatalysis. However, the facile and large-scale preparation of TMD monolayers with high-concentration unusual crystal phase still remains a challenge. Herein, we report the synthesis of MoX₂ (X = Se or S) monolayers with high-concentration semimetallic 1T′ phase by using the 4H/face-centered cubic (fcc)-Au nanorod as template to form the 4H/fcc-Au@MoX₂ nanocomposite. The concentrations of 1T′ phase in the prepared MoSe₂ and MoS₂ monolayers are up to 86% and 81%, respectively. As a proof-of-concept application, the obtained Au@MoS₂ nanocomposite is used for the electrocatalytic hydrogen evolution reaction (HER) in acid medium, exhibiting excellent performance with a low overpotential of 178 mV at the current density of 10 mA/cm², a small Tafel slope of 43.3 mV/dec, and excellent HER stability. This work paves a way for direct synthesis of TMD monolayers with high-concentration of unusual crystal phase for the electrocatalytic application.

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由于其在电催化中的应用前景广阔，具有异常晶相的过渡金属二硫化氢（TMD）单层的受控合成已引起越来越多的关注。但是，如何轻松，大规模地制备具有高浓度非常规晶相的TMD单层仍然是一个挑战。在本文中，我们报告了以4H /面心立方（fcc）-Au纳米棒为模板形成4H / fcc-Au合成具有高浓度半金属1T'相的MoX ₂（X = Se或S）单层的方法@MoX ₂纳米复合材料。制备的MoSe ₂和MoS ₂单层中1T'相的浓度分别高达86％和81％。作为概念验证应用程序，获得的Au @ MoS ₂纳米复合材料用于酸性介质中的电催化制氢反应（HER），具有优异的性能，在10 mA / cm ²的电流密度下具有178 mV的低过电势，43.3 mV / dec的小Tafel斜率和优异的HER稳定。这项工作为直接合成具有高浓度非常规晶相的TMD单层铺平了道路，以用于电催化应用。

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