Crystal phase modulations in two-dimensional (2D) materials have garnered extensive interest because of their intriguing features and potential applications. Nonetheless, synthesizing some specific phases of metastable transition metal dichalcogenides (TMDs) remains a challenge due to the restricted selectivity under chemical and physical treatments, especially for direct growth of specific phase of TMDs on 2D substrates to form heterostructures. Taking the merits of MXene with tunable atomic vacancies and surface chemistry via surface functionalization, the phase of epitaxially grown TMDs on 2D MXene can be significantly affected. In this work, 1 T′-MoS₂ and 1 T-MoSe₂ were directly grown on electrochemically synthesized MXene under controlled oxidization conditions and selected MXene substrate. Owing to the synergistic effect of TMDs and MXene, the TMDs/MXene heterostructure catalysts exhibit good electrochemical activity under acidic conditions, with a low overpotential of 167 mV at a current density of 10 mA cm⁻². Our work not only demonstrates the distinct chemical characteristic of various MXenes feasible for surface engineering which promotes the direct and in situ growth of phase controlled TMDs on MXene substrates but also displays the high electrochemical activity in TMDs/MXene heterostructure catalysts.

二维（2D）材料中的晶体相位调制因其有趣的特征和潜在的应用而引起了广泛的兴趣。尽管如此，由于化学和物理处理下的选择性受限，合成某些特定相的亚稳态过渡金属二硫属化物（TMDs）仍然是一个挑战，特别是对于在二维基板上直接生长特定相的 TMDs 以形成异质结构。通过表面功能化利用具有可调原子空位和表面化学的 MXene 的优点，可以显着影响 2D MXene 上外延生长的 TMD 的相位。在这项工作中，1 T'-MoS ₂和 1 T-MoSe ₂在受控氧化条件和选择的 MXene 基板上直接在电化学合成的 MXene 上生长。由于 TMDs 和 MXene 的协同效应，TMDs/MXene 异质结构催化剂在酸性条件下表现出良好的电化学活性，在 10 mA cm ^-2的电流密度下具有 167 mV 的低过电位。我们的工作不仅展示了可用于表面工程的各种 MXene 的独特化学特性，这促进了相控 TMD 在 MXene 基底上的直接和原位生长，而且还展示了 TMD/MXene 异质结构催化剂中的高电化学活性。