Mn-Doped Nickel Telluride Dirac Semimetals with Engineered Dirac Cones for Accelerated Energy Conversion: Synergistic...

Dirac semimetals are promising catalysts because of their unique electronic structures. In this study, we prepared a series of Ni_1-xMn_xTe₂ catalysts with varying Mn doping ratios via a simple one-step hydrothermal approach to modulate the electronic structure of Dirac semimetal NiTe₂. Density functional theory calculations reveal that Mn doping effectively modulates Dirac cone dispersion near the Fermi level of NiTe₂, thus significantly increasing the Fermi velocity. Furthermore, Mn doping substantially increases the density of states near the Fermi level and shifts the Dirac point to lower energies, thereby improving molecular adsorption. This synergistic modulation optimizes the catalytic activity of the triiodide reduction and hydrogen evolution reaction (IRR, HER). As a counter electrode, Ni_0.95Mn_0.05Te₂ exhibits a power conversion efficiency of 9.12%. Concurrently, as a HER catalyst, it exhibits an overpotential of 110 mV at 10 mA cm^-2. This paper presents an effective strategy for optimizing Dirac semimetal catalysts through electronic structure and adsorption site engineering, thus offering valuable insights for designing high-performance catalysts from topological quantum materials for electrochemical applications.