Role of V doping in core–shell heterostructured Bi2Te3/Sb2Te3 for hydrogen evolution reaction

Non-noble metal-based materials as low-cost hydrogen evolution reaction (HER) catalysts are key materials for sustainable hydrogen energy production. Bismuth and antimony chalcogenides are among the hopeful candidates to achieve this goal. In this work, a V-doped Sb2Te3 encapsulated Bi2Te3 core-shell electrocatalyst (Bi2Te3/Vx-Sb2Te3) has been synthesized by a two-step solvothermal method. V doping adjusts the electronic structure of catalyst, dramatically enhances electric double layer capacitance (Cdl) of the catalyst, decreases charge transfer resistance (Rct) of the catalyst and increases carrier concentration of the catalyst. Therefore, the V doping method increases the active sites on the surface of the material, and promotes the charge transfer and electron transport in the HER process. In addition, V doping can also adjust the hydrophilicity of the material surface, promote the release of hydrogen, and quickly re-expose the active sites. Bi2Te3/Vx-Sb2Te3 electrocatalysts exhibit brilliant HER activity and high stability in both acidic and alkaline electrolytes. This study uses the strategy of V doping to control the electronic structure of materials, which will provide suggestions for the design and preparation for other high-activity catalysts.