화학공학소재연구정보센터
Journal of Catalysis, Vol.381, 493-500, 2020
Accelerating water dissociation kinetics on Ni3S2 nanosheets by P-induced electronic modulation
Developing efficient and low-cost electrocatalysts for hydrogen evolution reaction (HER) is important in clean energy systems. Non-noble transition metals are the most promising candidates for the replacement of conventional Pt group catalysts of HER. However, most non-noble metals show poor HER activity due to the intrinsic electronic structures. Herein, P atoms doped Ni3S2 (P-doped Ni3S2) nanosheets array grown on Ni foam has been successfully synthesized and further applied as the efficient electrocatalysts for HER in alkaline media. P-doped Ni3S2 shows higher catalytic activity for HER compared with pristine Ni3S2, which affords the current densities of 10 mA cm(-2) at an overpotential of 139 mV and long-term stability over 110 h. Density functional theory (DFT) calculations reveal that the introduction of P atoms modify the electronic structure of Ni3S2, enhance the electrical conductivity, optimize the HER Gibbs freeenergy (Delta G(H*)) and the change of water adsorption energy (Delta G(H2O*)), and reduce the barrier of water dissociation optimize the HER Gibbs free-energy (Delta G(H*)), change water adsorption energy (Delta G(H2O*)) and reduce the barrier of water dissociation. Remarkably, energy integral of a crystal orbital Hamilton population (ICOHP) gives access to the contribution of an atom or a chemical bond to the distribution of oneparticle bonding within the transistion state of water dissociation and reveals the reduced essence of water dissociation barrier. (C) 2019 Elsevier Inc. All rights reserved.