Hetero-phase Pd4S metallene nanoribbons with Pd-rich vacancies for sulfur ion degradation-assisted hydrogen production

Vacancy defects and crystal-phase are essential parameters that affect surface electronic structure. It is still a great challenge to introduce both vacancy defects and unconventional crystal-phase into electrocatalysts to investigate their effects on the electrocatalytic performance. Herein, we in-situ constructed ultrathin Pd4S metallene nanoribbon with Pd-rich vacancies (VPd-Pd4S MNRs) via hydrothermal sulfuration for outstanding hydrogen evolution reaction (HER) and sulfion oxidation reaction (SOR) performance. Based on the metallene morphology, synergistic effect of Pd vacancies and crystal-phase, VPd-Pd4S MNRs exhibits excellent activity and long-term stability, reaching 100 mA cm−2 at 0.776 V to accomplish the simultaneous hydrogen production and sulfur ion degradation. As confirmed by density functional theory (DFT) simulations, the vacancies and S atoms affect electronic structure of catalyst surface, modulating the d-band center of Pd and thus optimizing the adsorption/dissociation during catalytic process. This work presents a promising method to simultaneously construct metal vacancies and crystal-phase in metallene electrocatalysts.