| 초록 |
The massive depletion of fossil energy, as well as the resulting environmental issues, has prompted a strong interest in identifying various renewable and sustainable energy sources to replace traditional fossil fuels in energy conversion and storage. The various non-noble metal-based electrocatalysts that were exhibited good electrocatalytic activity, especially, the nickel have an excellent advantage of electrical conductivity and weakly adsorbing protons because of their low Gibbs free energy. Here, we synthesized a highly porous Ni3S2-C foam that exhibits excellent performance with respect to HER, including high proton adsorption ability, high electrical conductivity, and large surface area. Moreover, the Ni3S2-C electrode exhibited a low overpotential of 70 mV at 10 mA/cm2 with a Tafel slope of 76 mV/dec, which is close to that of the benchmark Pt/C catalyst. We also performed a comprehensive theoretical study on the HER performance of Ni3S2-X-CX using DFT, including the electronic properties of low-index surfaces with various terminations. The results show that carbon-doped Ni3S2 improves the electrocatalytic efficiency because of the low Gibbs free energy of its surface. |
