Ru‐Pincer Complex‐Bridged Cu‐Porphyrin Polymer for Robust (Photo)Electrocatalytic H2 Evolution via Single‐Atom Active Sites

Abstract

AbstractOrganic polymers have attracted much attention in the field of energy conversion owing to their excellent tailoring ability via heterometal incorporation and/or functionalization. Herein, a novel pincer complex‐bridged porphyrin polymer is synthesized using Cu‐porphyrin (CuPor) and Ru‐N′NN′‐pincer complex (RuN3) as monomers. The resultant CuPor‐RuN3 polymer delivers robust electrocatalytic hydrogen evolution reaction (HER) performance with outstanding durability and ultralow overpotentials of 73 and 114 mV at a current density of 10 mA cm‐2 in acidic and alkaline media, respectively. Moreover, the CuPor‐RuN3 polymer displays great potential to fabricate photoelectrochemical (PEC) cells with a BiVO4 photoanode, where the additional photoinduced electrons from CuPor‐RuN3 endow the BiVO4||CuPor‐RuN3 PEC cell with much better activity for overall water splitting than the BiVO4||Pt/C one, demonstrating that CuPor‐RuN3 would be a promising (photo)electrocatalyst to replace the benchmark Pt/C. The experimental and theoretical studies reveal that the Cu/Ru heterobimetallic centers in the polymer not only enhance the inherent electron transfer from Cu sites to Ru ones that serve as single‐atom catalytic sites (Ru‐N3), but also efficiently regulate the electronic property of the Ru‐N3 sites, and thus boosting (photo)electrocatalytic HER activity. The proposed strategy opens a new avenue to fabricate porphyrin‐based polymers with heteromultimetallic centers as effective HER (photo)electrocatalysts.