Defect-mediated successive ionic layer adsorption and reaction for constructing Sb₂Te₃/Ag₂S heterojunction to boost hydrogen evolution reaction performance

As a sustainable and green technology for producing high-purity hydrogen, hydrogen evolution reaction (HER) has received extensive attention. The development of an electrocatalyst with good HER activity is the key to economic water electrolysis. Here, this work reports a defect-mediated successive ion layer adsorption and reaction method to construct Ag2S/irradiated Sb2Te3 heterojunctions with good HER activity. First, ion irradiation is used to introduce a large number of defects into Sb2Te3. The defective Sb2Te3 is continuously cyclically immersed in AgNO3 solution and Na2S solution. Ag+ and S-2 ions are adsorbed on the defect sites of Sb2Te3 and deposited as Ag2S and the heterojunction of Ag2S/irradiated Sb2Te3 is obtained. By this strategy, the electrochemical active surface area of the material is increased, reduces the charge transfer resistance, and improves the hydrophilicity of the material surface, thus exhibiting good HER activity. In this work, ion irradiation is used to regulate the surface defects of materials and then to regulate the growth of heterojunction to achieve the purpose of regulating the properties of material. The heterojunction growth method controlled by defect engineering can be widely used in the preparation of heterojunction materials in other energy and environmental fields.