Overdoping Strategy for Preparing a Two‐Phase Oxide Electrocatalyst to Boost Oxygen Evolution Reaction. Issue 11 (14th April 2022)

• Record Type: Journal Article
• Authors: Cai, Jian; Quan, Wei; Chen, Tianyi; Ye, Daixin; Zhao, Hongbin; Wu, Chengzhang
• Is Part Of: Chemistry, an Asian journal. Volume 17:Issue 11(2022)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2022-04-14
• Subjects: Electrocatalysis -- Oxygen evolution reaction -- Double perovskite -- Cobalt oxide -- two-phase; Chemistry -- Periodicals; 540.5
• DOI: 10.1002/asia.202200127
• Languages: English
• ISSNs: 1861-4728

Abstract

Abstract: The oxygen evolution reaction is of great significance to the production of hydrogen from high efficiency electrolytic water, hydrogen oxygen fuel cell and other energy conversion devices, but there are many challenges such as high cost, low efficiency and poor stability of catalysts. Among non‐precious metal catalysts, oxide has its unique advantages. We used overdoping strategy to prepare two‐phase oxide electrocatalyst SrCo0.9 Fe0.05 Mo0.35 Ox (SCFM0.35 ) containing double perovskite and Co3 O4 with excellent OER electrocatalytic activity and stability in alkaline solution. It required an overpotential of 361.7 mV to reach a 10 mA cm −2 current density and its performance only degrades by 3.48% after 1000 CV cycles accelerated stability tests, whose electrochemical performance is superior to that of single‐phase double perovskites and undoped perovskites. SrCo0.9 Fe0.1 O3 (SCF) ordinary perovskite is doped with slightly molybdenum (Mo), and then the ordinary perovskite turns into double perovskite because of the polyvalence characteristics of Mo. When Mo is overdoped, Co3 O4 phase was precipitated while Mo entered perovskite phase. This process causes lattice distortion and makes the surface electronic structure benign changes. Furthermore, the microscopic morphology of the material surface and the valence state of cobalt element are changed, thereby improving the microenvironment of the electrochemical process. Abstract : After doping a small amount of molybdenum (Mo) into the SrCo0.9 Fe0.1 O3 ordinary perovskite, the ordinary perovskite becomes a double perovskite due to the multivalent property of Mo. Moreover, with the increase of Mo doping amount, Mo can still enter into the double perovskite phase, while Co element is precipitated to form Co3 O4 . When the Mo doping amount reaches 0.35, the synergistic effect between the double perovskite and Co3 O4 phases enhances the catalytic activity and electrochemical stability of OER.