Oxygen vacancies meet partial S substitution: an effective strategy to achieve obvious synergistic effects and adjustable electrochemical behavior in NiFe-LDH for enhanced OER and capacitive performance

Abstract

A bifunctional electrode (oxygen evolution reaction (OER) and capacitive property) with high electrochemical activity is crucial for both supercapacitors and water splitting devices. Herein, a S and oxygen vacancy co-doped...

Homogenic Boundary Effect Boosted Oxygen Evolution Reaction in α/β‐NiMoO4 for Rechargeable Aqueous Zn‐Air Battery

“…[ 25 ] The peak of O III at 533.2 eV represents hydroxyl groups, [ 26 ] while O II at 531.9 eV is associated with surface oxygen vacancy species reported. [ 27 ] Surprisingly, the oxygen vacancy ratio in NMO‐600 is estimated to be 29.5%, significantly higher than that of the NMO‐400 (5.6%), NMO‐500 (24.7%) and NMO‐700 (16.3%), as shown in Figure 3c. This is further supported by temperature‐programmed desorption of oxygen gas (O 2 ‐TPD) results presented in Figure S20 (Supporting Information), indicating that NMO‐600 possesses a greater amount of surface‐active oxygen adsorbed on the oxygen vacancies, [ 28 ] in agreement with the XPS analysis.…”

MOF-Derived Hollow Heterostructure MnCo2O4@Co9S8 Nanocages as a High-Performance Bifunctional Electrode for Water Electrolysis and Flexible Supercapacitor

“…Each sample showed approximately symmetrical redox peaks corresponding to the redox processes of Co 2+ /Co 3+ and Mn 3+ /Mn 4+ species, which were characteristic of the Faraday cell types. 57 The MnCo 2 O 4 @Co 9 S 8 -10 electrode exhibited a higher redox peak strength and CV area, which represent a larger capacitor capacity and the ability to store more electrical energy. The galvanostatic charge-discharge (GCD) curves of different synthesized electrodes at a current density of 0.5 A g −1 (Figure 5b) all have symmetrical charge and discharge curves and obvious charge and discharge platforms, further confirming the Faraday characteristics of this battery type.…”

“…Cyclic voltammetry (CV) curves of different electrode materials tested at a constant scanning rate of 100 mV s –1 are shown in Figure a. Each sample showed approximately symmetrical redox peaks corresponding to the redox processes of Co 2+ /Co 3+ and Mn 3+ /Mn 4+ species, which were characteristic of the Faraday cell types . The MnCo 2 O 4 @Co 9 S 8 -10 electrode exhibited a higher redox peak strength and CV area, which represent a larger capacitor capacity and the ability to store more electrical energy.…”

High ratios of Ni3+ and Co3+ facilitated by Mn-addition for enhanced oxygen evolution reaction and ethanol oxidation reaction

“…As a matter of fact, there have been many reports on non-precious metal catalysts for the OER or EOR individually, 20–25 but there are few reports on bifunctional catalysts capable of both the oxygen evolution reaction and ethanol oxidation reaction. Therefore, designing dual-functional catalysts is crucial for electrocatalytic hydrogen production.…”