Topologically nontrivial 1T’-MoTe₂ as highly efficient hydrogen evolution electrocatalyst

Abstract Rational design and synthesis of low-cost noble-metal free electrode with high efficiency for hydrogen evolution reaction (HER) is crucial for the realization of eco-friendly hydrogen economy. Here, we report and design topologically nontrivial 1T’-MoTe₂ single crystals as remarkable hydrogen evolution electrocatalyst. The catalytic 1T’-MoTe₂ was controllably synthesized via solid-state reaction and then facilely exfoliated into nanosheets by isopropanol with the aid of sonication. The overpotentials at 10 mA cm⁻²( η ₁₀) can reach 73 mV with a low Tafel slope of 46.3 mV dec⁻¹, which are much lower than those reported by other preparation methods (η ₁₀ > 300 mV, Tafel slope > 50 mV dec⁻¹). The electrochemical impedance spectroscopy shows fast kinetics of 1T’-MoTe₂ single crystal with low contact resistance of 0.3 Ω. Additionally, 1T’-MoTe₂ single crystal also exhibits large electrochemical active surface area of 47.0 cm², high turnover frequency of 1.02 s⁻¹ at 0.4 V and excellent durability over 10 h in 0.5 M H₂SO₄( aq). This work reports 1T’-MoTe₂ single crystal as an excellent candidate for HER, which makes it possible to fabricate other robust Te-derived HER electrocatalysts.