Electrocatalytic hydrogen evolution properties of anionic NiS2-Ni(OH)2 nanosheets produced on the surface of nickel foam

Summary To circumvent the expensive cost of precious metal electrocatalysts, a hydrothermal method and a plasma-enhanced chemical vapor deposition (PECVD) method have been used to prepareNiS 2 -Ni(OH) 2 /NF-PECVD (N-PECVD) with excellent properties. After XRD, SEM, XPS, and other characterization methods, it can be seen that after the hydrothermal reaction of Ni foam (NF), 50-60 nm Ni(OH) 2 nanosheets have grown on the NF frame. The subsequent PECVD reaction produces 90 nm NiS 2 -Ni(OH) 2 nanosheets on the NF frame. The hydrogen release overpotentials in the acidic solution and alkaline solution are 90 and 95 mV ( j = 10 mA/cm 2 ), respectively. And the Tafel slopes reach 80 and 83.6 mV/dec, respectively. The chronopotential (CP) test shows that the material has good HER stability over 12 h. The results from the subsequent electric double layer capacitance and alternating current impedance (EIS) tests show that N-PECVD synthesized by PECVD has a relatively large active electrochemical surface area (ECSA) and a low electrochemical impedance. This study not only finds good inspiration for the synthesis of cheap HER catalysts but also provides a valuable reference for the synthesis of materials in other fields.