Self-supported anodic film of Fe(III) redox center doped Ni-Co Prussian blue analogue frameworks with enhanced catalytic activity towards overall water electrolysis
Seog Joon Yoon, Hoa Thi Bui, Soo Jeong Lee, Supriya A. Patil, Chinna Bathula, Nabeen K. Shrestha, Hyunsik Im
Abstract
This work reports on in-situ doping of Fe(III) redox centers to NiCo based Prussian blue analogue framework films and their eletrocatalytic performance towards water splitting into molecular hydrogen and oxygen. Uniform and self-supported films of frameworks are deposited onto nickel substrate via anodization in 80 vol % glycerol based aqueous electrolyte containing 0.1 M K3[Co(CN)6] with/without addition of a small amount of [Fe(CN)6]3− as doping precursor. XRD, HR-TEM, STEM and XPS characterization of the film confirmed the doping. Notably, the doped film demonstrated an enhanced electrocatalytic activity towards hydrogen and oxygen evolution reaction in alkaline electrolyte with small overpotentials of 169 and 263 mV, respectively to derive the benchmark current density of 10 mAcm−2. In addition, bulk electrolysis at 10 mAcm−2 demonstrated an improved and well-maintained long-term electrochemical durability of the doped film-based cathode and anode for overall splitting of water.