Type‐II Weyl Semimetal Mo‐Doped WTe 2 : Urea Colloid Reduction Synthesis and Theoretical Confirmation of Topological Surface States for Energy Conversion Applications

Abstract Pure topological Weyl semimetals with nanostructures are prepared for efficient electron transfer in a universal and simple manner. Herein, a urea‐assisted reduction‐inert vapor deposition method is presented for the synthesis and characterization of three type‐II Weyl semimetals: WTe 2 , MoTe 2 , and W 1‐x Mo x Te 2 . Owing to its high charge carrier mobility and robust topological surface states, Weyl semimetal W 1‐x Mo x Te 2 exhibits superior electrocatalytic performance and stability when employed as a counter electrode. By performing density functional theory calculations, the optimization of the triiodide reduction reaction (IRR) and hydrogen evolution reaction (HER) is systematically investigated via Mo doping. Furthermore, an energy band structure analysis based on density functional theory (DFT) is performed, which confirms the preservation of robust topological properties in the doped system. For the IRR, W 0.93 Mo 0.07 Te 2 achieves a power conversion efficiency of 8.96%, which is superior to that of a conventional platinum electrode (7.22%). When W 0.93 Mo 0.07 Te 2 is used as an electrocatalyst for the HER, it exhibits a low overpotential of 143 mV when the current density is 10 mA cm −2 , significantly outperforming other Weyl semimetals. This paper presents a new method for preparing Weyl semimetals and provides a new direction for investigating multifunctional topological quantum materials.