Co₃O₄|CoP Core–Shell Nanoparticles with Enhanced Electrocatalytic Water Oxidation Performance

Abstract

Developing high performance, cost-effective, and durable electrocatalysts that must be derived from non-noble metals is crucial for alkaline oxygen evolution reaction (OER). OER, which takes place at the anode, is accepted as a major obstacle for commercialization due to its sluggish kinetics. In this study, a two-step synthesis method, such as a hydrothermal process followed by the annealing of the reactants in an Ar-filled Swagelok cell, is briefly described to obtain a cubic type of Co3O4 core and CoP shell. As a result of synergy, Co3O4|CoP demonstrates an onset overpotential of 280 mV and reaches a current density of 10 mA cm–2 at an overpotential of 320 mV in an alkaline medium (pH = 13.5). The electronic property of the heterojunction is verified by the Tauc plot and valence band XPS. The band structure indicates that Co3O4|CoP exhibits a more metallic character than pristine Co3O4 due to the fact that the charge transfer process is faster. Further, the introduction of CoP significantly modifies the redox processes of Co3O4, which we examined with the help of large amplitude alternating current voltammetry (LA-ACV). The mechanistic study suggests that “catalytic performance is directly related to the peak-to-peak current density” of the redox process of the combined catalyst and reactant.

Cobalt–Copper Bimetallic Phosphide/Carbon Nanocomposites Derived from Metal–Organic Frameworks for Sodium-Ion Batteries

“…The peaks at 129.3 and 130.3 eV in Figure d correspond to P 2p 3/2 and P 2p 1/2 levels, respectively. At 133.8 eV, there is a notably wider peak, which can be related to surface oxidation (P–O bonds) . The binding energy of the Co peak in CoCuP@C-2 is shifted to a lower position compared to that of CoP due to the interaction between Cu and Co, further suggesting that the Cu element is incorporated into the lattice of CoP, in agreement with the XRD results.…”

“…At 133.8 eV, there is a notably wider peak, which can be related to surface oxidation (P−O bonds). 49 The binding energy of the Co peak in CoCuP@C-2 is shifted to a lower position compared to that of CoP due to the interaction between Cu and Co, further suggesting that the Cu element is incorporated into the lattice of CoP, in agreement with the XRD results. Assembled half-cells were assembled to test the SIB performance of CoCuP@C-2 composites.…”

Synthesis of ethane-disulfonate pillared layered cobalt hydroxide towards the electrocatalytic oxygen evolution reaction

“…This redox procedure can be assigned to the electron transfer in the formation of oxygen radicals. 50,52 The symmetry and shape of the third and fourth harmonic profiles resemble those of the amorphous CoO x films, which indicates that the rate-determination step is the formation of Co( iv )–O radical intermediates on the surface of the catalyst. The amplified current in the positive scan is higher than that in the negative scan, demonstrating rapid kinetics in the positive scan.…”

A Facile Synthetic Approach for TiO2@NiO Core‐shell Nanoparticles using TiO2@Ni(OH)2 Precursors and their Photocatalytic Application

“…[3] In literature, different metal oxide-based CSNPs have been reported for various applications. For example, SiO 2 /NiO CSNPs and Fe 3 O 4 @NiO for selective adsorption of toxic dyes, [4,5] ZnCo 2 O 4 @NiO, Co 3 O 4 @NiCo 2 O 4 nanowires, Fe 2 O 3 @NiCo 2 O 4 , and MnCo 2 O 4 @NiO for asymmetric supercapacitors, [6][7][8][9] Au@Co 3 O 4 and TiO 2 /SnO 2 core-shell nanorods for gas sensing applications, [10,11] TiO 2 @α-Fe 2 O 3 and α-Fe 2 O 3 @TiO 2 for photocatalytic degradation, [12,13] Fe 2 O 3 @TiO 2 and Co 3 O 4 /CoP for CO and water oxidation, [14,15] Co 3 O 4 @LaCoO 3 for water splitting, [16] SiO 2 @MnCo 2 O 4 for peroxidase-like activity, [17] TiO 2 @Ag for reduction of 4-nitrophenol, [18] and Cu x O@TiO 2 for antibacterial activity. [19] TiO 2 is a n-type semiconductor with a wide band gap of ~3.2 eV.…”