Ru sensitized MOF electronic structure for efficient water electrolysis

Metal-organic framework (MOF) materials have become potential catalysts for water electrolysis due to their strong structural and functional adjustability. However, the intrinsic activity of MOF catalyst is low due to its weak charge transfer ability and limited stability. Therefore, it is still a challenging problem to design MOF catalysts with high activity and high stability. In this paper, CoRu-BDC/NF(BDC: terylene acid, NF: nickel foam) was successfully synthesized by two-step hydrothermal method. The introduction of Ru regulated the intrinsic activity of Co-BDC loaded on NF, endowed CoRu-BDC/NF with abundant active sites and fast charge transport capacity, which was conducive to the improvement of electrocatalytic performance. The results show that when the current density of CoRu-BDC/NF reaches 10 mA·cm⁻² in acidic environment, HER overpotential is 34 mV and Tafel slope is 33 mV·dec⁻¹. It is worth noting that under alkaline conditions, when the current density is 10 mA·cm⁻², the required overpotential of HER and OER is only 32 mV and 280 mV, and the slope of Tafel is 39 mV·dec⁻¹ and 49 mV·dec⁻¹, showing excellent electrocatalytic performance. The introduction of Ru leads to changes in the electronic structure and coordination environment of Co, increasing the surface area of the original Co-MOF, providing a better electron transfer platform for the electrochemical reaction, speeding up the transfer of electrons between the electrode and the electrolyte interface, and further improving the electrocatalytic performance.