Electrochemically Deposited Amorphous Cobalt–Nickel-Doped Copper Oxide as an Efficient Electrocatalyst toward Water Oxidation Reaction

Abstract

Production of hydrogen through water splitting is one of the green and the most practical solutions to cope with the energy crisis and greenhouse effect. However, oxygen evolution reaction (OER) being a sluggish step, the use of precious metalbased catalysts is the main impediment toward the viability of water splitting. In this work, amorphous copper oxide and doped binary-and ternary-metal oxides (containing Co II , Ni II , and Cu II ) have been prepared on the surface of fluorine-doped tin oxide by a facile electrodeposition route followed by thermal treatment. The fabricated electrodes have been employed as efficient binder-free OER electrocatalysts possessing a high electrochemical surface area due to their amorphous nature. The cobalt−nickel-doped copper oxide (ternary-metal oxide)-based electrode showed promising OER activity with a high current density of 100 mA cm −2 at 1.65 V versus RHE that escalates to 313 mA cm −2 at 1.76 V in alkaline media at pH 14. The high activity of the ternary-metal oxide-based electrode was further supported by a smaller semicircle in the Nyquist plot. Furthermore, all metal-oxide-based electrodes offered high stability when tested for continuous production of oxygen for 50 h. This work highlights the synthesis of efficient and costeffective amorphous metal-based oxide catalysts to execute electrocatalytic OER employing an electrodeposition approach.

Regulated Bimetal-Doped Polyaniline: Amorphous-Crumple-Structured Viable Electrocatalyst for an Efficient Oxygen Evolution Reaction

“…The organized crumple NP structure with an amorphous phase may provide limited bubble adhesion and high RF, which generate multi-channels to assist the release of gas bubbles from the electrode surface, thus minimizing bubble accumulation and preventing catalyst peel off from the substrate. 70 The exceptional OER activity and stability of the Co 4 Ni 1 @PANI/GC electrode initiated us to develop costeffective anode material for a profitable water splitter. The as-prepared Co 4 Ni 1 @PANI catalyst (0.5 mg cm −2 ) was homogeneously coated on nickel foam (NF) as a current collector (Co 4 Ni 1 @PANI/NF) to enhance the active surface area and reduce the strain by giving a way for O 2 evolution in alkaline medium.…”

“…When the metal composition (Co/Ni = 3:2, 2:3, and 1:4) was altered from the optimal ratio of Co 4 Ni 1 @PANI, the adsorption sites were diminished. The organized crumple NP structure with an amorphous phase may provide limited bubble adhesion and high RF, which generate multi-channels to assist the release of gas bubbles from the electrode surface, thus minimizing bubble accumulation and preventing catalyst peel off from the substrate . The exceptional OER activity and stability of the Co 4 Ni 1 @PANI/GC electrode initiated us to develop cost-effective anode material for a profitable water splitter.…”

Binder-Free Fabrication of Prussian Blue Analogues Based Electrocatalyst for Enhanced Electrocatalytic Water Oxidation

“…It has also been observed that conventional electrode fabrication using a binder, can lead to the undesirable electrode interface, i.e., higher resistance amid electrocatalyst and substrate, thereby lessening the active sites and flaking off the catalyst etc. Therefore, binder-free electrocatalysts are advantageous to boost the catalytic performances of PBAs [ 17 , 18 ]. Moreover, the in situ growth of a conductive layer i.e., graphene, CNTs and surfactants, etc., onto an electrode and electrocatalyst interface is an effective tactic to construct an electron pathway and regulate electron transference between them [ 17 , 18 , 19 , 20 ].…”

“…Therefore, binder-free electrocatalysts are advantageous to boost the catalytic performances of PBAs [ 17 , 18 ]. Moreover, the in situ growth of a conductive layer i.e., graphene, CNTs and surfactants, etc., onto an electrode and electrocatalyst interface is an effective tactic to construct an electron pathway and regulate electron transference between them [ 17 , 18 , 19 , 20 ].…”

Effects of Capping Agents on Shape, Stability, and Oxygen Evolution Reaction Activity of Copper Nanoparticles

“…[26][27][28][29] The capping ligands stabilize the contact between the nanoparticles and the preparation medium. [30][31][32] Certain structural features of nanoparticles are caused by the capping on their surface. The stabilizing compounds are essential for altering the action.…”