Highly exposed ruthenium-based electrocatalysts from bimetallic metal-organic frameworks for overall water splitting

The development of highly exposed active sites and highly active inexpensive electrocatalysts is important and challengeable for electrocatalytic hydrogen evolution reaction (HER). Herein, we report a bimetallic metal-organic frameworks based strategy to fabricate Ru-based electrocatalysts with high exposure of the Ru active sites (Ru-HPC, ruthenium-decorated hierarchically porous carbon) for high efficient hydrogen evolution. Remarkably, Ru-HPC achieves a current density of 25 mA cmgeo−2 at an overpotential of 22.7 mV, and shows an ultrahigh turnover frequency of 1.79 H2 s−1 at 25 mV, which is almost twice higher than that of commercial Pt/C. The electrochemical HER performance of Ru-HPC surpasses most of the electrocatalysts reported so far in alkaline solutions. Besides, a two-electrode water splitting device is constructed with Ru-HPC and porous RuO2 (obtained by oxidizing Ru-HPC) as electrode materials, which achieves a current density of 10 mA cm−2 at only 1.53 V. This work provides a facile strategy to fabricate high-performance metal-carbon hybrid electrocatalysts with abundant exposed active sites from bimetallic MOFs, which can hopefully be applied to many other metals-carbon hybrids for various electrochemical applications in the foreseeable future.