Double MOF gradually activated S bond induced S defects rich MILN-based Co(z)-NiMoS for an efficient electrocatalytic overall water splitting

Herein, cactus like nanorods with rich S defects and function groups MILN-based Co(z)-NiMoS are synthesized through a facile method. First, we prepare MIL-88B precursor to give a fairly dispersed frame structure, and then Con+ was doped into disulfides which are rich in sulfur bonds and the imidazole group was cleverly connected into graphitized carbon via self-etching of ZIF-67. The doping of Con+ and function groups makes the tiny changes in the lattice of sulfide which promotes the unsaturation degree of S bond and activated it gradually. The prepared semi frame sulfide with unique structure on the one hand ensures the hydrophilicity and multiple active specific surface area which lays superior functions in morphology. On the other hand, coupling metals that have strong valence change ability and functional groups by active S bond plays an important role in the process of electrocatalytic reaction. Amazingly, disintegration and self-reconstruction of MILN-based Co(z)-NiMoS are happened during oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) due to the activation of S bond, which provides a new perspective for the overall water splitting mechanism. The electrochemical results show that the MILN-based Co(z)-NiMoS electrocatalyst making it possible that the overpotential of HER, OER and overall water splitting (OWS) is 169 mV, 170 mV and 1.466 V, respectively, making it a promising electrode material for OWS applications.