TY - JOUR
T1 - Development of α‐MnO2 Nanowire with Ni and (Ni, Co) – Cation Doping as an Efficient Bifunctional Oxygen Evolution and Oxygen Reduction Reaction Catalysts
AU - Selvakumar, Karuppiah
AU - Duraisamy, Velu
AU - Venkateshwaran, Selvaraj
AU - Arumugam, Natarajan
AU - Abdulrahman I., Almansour
AU - Wang, Yucheng
AU - Liu, Terence Xiaoteng
AU - Kumar, Sakkarapalayam Murugesan Senthil
N1 - Funding information: We would like to acknowledge Director, CSIR-Central Electrochemical Research Institute (CECRI) for support and encouragement. Selvakumar thanks the financial support through the CSIR-HRDG, New Delhi, India for SRF (grant no. 31/20(159)2k17). The project was supported by Researchers Supporting Project number (RSP-2021/143), King Saud University, Riyadh, Saudi Arabia.
PY - 2022/1/27
Y1 - 2022/1/27
N2 - Manganese oxides (MnO 2 ) with nanowire morphology materials are a promising candidate for improving oxygen evolution and oxygen reduction reaction (OER/ORR) performance. In this work, we developed transition metal cation doping strategy into the α-MnO 2 tunnel structure to tune the Mn oxidation states and control the uniform nanowire morphology, crystalline structure in order to investigate the effect of doping over bifunctional activity. The single Ni 2+ cation doping in α-MnO 2 with various loading concentrations resulted in 8Ni-MnO 2 exhibiting remarkable OER and ORR activity owing to their excessive concentration of Mn 3+ and Mn 4+ octahedral sites respectively. Further, Co 2+ cation doping in 8Ni-MnO 2 leads to an enhanced synergistic effect that significantly improves the fraction of Mn 3+ quantity which is confirmed by average oxidation state. For, electrochemical OER performance of 8Co-8Ni-MnO 2 exhibits a potential of 1.77 V, Tafel slope value of 68 mV dec -1 and lower charge transfer resistance and it is active in ORR with more positive onset potential of 0.90 V, half-wave potential of 0.80 V, better current density (4.7 mA cm -2 ) and a four-electron pathway. Moreover, bifunctional activity (ΔE = E OER @10 mA cm -2 – ORR@E 1/2 ) of 8Co-8Ni-MnO 2 demonstrated 0.97 V, indicates an excellent activity in alkaline electrolyte solution.
AB - Manganese oxides (MnO 2 ) with nanowire morphology materials are a promising candidate for improving oxygen evolution and oxygen reduction reaction (OER/ORR) performance. In this work, we developed transition metal cation doping strategy into the α-MnO 2 tunnel structure to tune the Mn oxidation states and control the uniform nanowire morphology, crystalline structure in order to investigate the effect of doping over bifunctional activity. The single Ni 2+ cation doping in α-MnO 2 with various loading concentrations resulted in 8Ni-MnO 2 exhibiting remarkable OER and ORR activity owing to their excessive concentration of Mn 3+ and Mn 4+ octahedral sites respectively. Further, Co 2+ cation doping in 8Ni-MnO 2 leads to an enhanced synergistic effect that significantly improves the fraction of Mn 3+ quantity which is confirmed by average oxidation state. For, electrochemical OER performance of 8Co-8Ni-MnO 2 exhibits a potential of 1.77 V, Tafel slope value of 68 mV dec -1 and lower charge transfer resistance and it is active in ORR with more positive onset potential of 0.90 V, half-wave potential of 0.80 V, better current density (4.7 mA cm -2 ) and a four-electron pathway. Moreover, bifunctional activity (ΔE = E OER @10 mA cm -2 – ORR@E 1/2 ) of 8Co-8Ni-MnO 2 demonstrated 0.97 V, indicates an excellent activity in alkaline electrolyte solution.
KW - cobalt doping
KW - manganese oxides
KW - OER/ORR electrode
KW - RRDE
KW - Tafel slope
U2 - 10.1002/celc.202101303
DO - 10.1002/celc.202101303
M3 - Article
VL - 9
JO - ChemElectroChem
JF - ChemElectroChem
SN - 2196-0216
IS - 2
M1 - 202101303
ER -