Creating Dual Active Sites in Conductive Metal-Organic Frameworks for Efficient Water Splitting

摘要

The achievement of bifunctional metal-organic frameworks (MOFs) remainsa huge challenge due to their lack of dual active sites. Herein, dual sites in theCo-catecholate (Co-CAT) are created through Ru, Ir, or Rh doping for overallwater splitting. Among them, RuCo-CAT exhibits excellent bifunctional activities,outperforming benchmarked Pt/C for the hydrogen evolution reaction (HER)and RuO_2 for the oxygen evolution reaction (OER). The theoretical calculationsdemonstrate that the doped Ru atoms with optimal absorption energy for thehydrogen intermediate and the Co centers with a reduced energy barrier for therate-determining step are the active sites for HER and OER, respectively. Furthermore,the incorporation of Ru atoms can improve the electrical conductivityand capacity of water adsorption of Co-CAT greatly, synergistically improving thebifunctional activity. This strategy for engineering dual active sites offers novelinsights into designing bifunctional MOFs for overall water splitting.