Partially sulfurated ultrathin nickel-iron carbonate hydroxides nanosheet boosting the oxygen evolution reaction

Ultrathin nickel-iron carbonate hydroxides nanosheets/sulfides (denoted as NixFeyS/CH) are fabricated by sulfurizing treatment of nickel-iron carbonate hydroxide (NixFeyCH). The partial sulfuration of NiFe carbonate hydroxides by replacing the CO3/OH groups with the S group can well remain the hexagonal morphology, regulate the electronic structure and expose more electrochemical active sites. Benefiting from the ultrathin-layered sheet with mesoporous structure for more available active sites, the strong coupling between metal carbonate hydroxides/sulfides, as well as bimetal synergism for modulation the composition and electronic structure, the optimal NixFeyS/CH exhibits excellent OER catalytic performance, which reaches 20 mA cm−2 at an ultra-small overpotential of 261 mV, lower Tafel slope (103 mV dec−1) and outstanding stability. This work highlights the importance regarding the modulation of composition and electronic structure by the interface coupling and bimetal synergism for boosting OER performance.