NiCo 2 O 4 hexagonal nanoplates anchored on reduced graphene oxide sheets with enhanced electrocatalytic activity and stability for methanol and water oxidation

In-situ developed carbon spheres function as promising support for enhanced activity of cobalt oxide in oxygen evolution reaction

Highly active, stable electrocatalyst for oxygen evolution reaction (OER) is sincerely required for the practical application of water splitting to get rid from the sluggish reaction kinetics and the stability issue. Here, Co₃O₄ is studied as OER catalyst and to improve the electrocatalytic activity, carbon is chosen as the conducting support. A simple and cost-effective synthetic route is developed for the synthesis of Co₃O₄ on carbon support following hydrothermal route using various hydrolyzing agents. The heterostructure 'Co₃O₄/C' perform well in OER as a non-precious metal catalyst. The best Co₃O₄/C electrocatalyst can generate 10 and 30 mA/cm² current densities upon application of 1.623 V and 1.678 V vs. RHE whereas, bare Co₃O₄ can generate current density of 10 and 30 mA/cm² upon application of 1.677 and 1.754 V vs. RHE. Carbon in the heterostructure helps to improve the conductivity and at the same time enhances the charge transfer ability which further leads to increase current density and stability to the catalyst. Co₃O₄/C can generate unaltered current density up to 1000 cycles.

2D/2D FeOCl/graphite oxide heterojunction with enhanced catalytic performance as a photo-Fenton catalyst

A novel 2D/2D FeOCl/graphite oxide heterojunction has been successfully prepared for the first time and shows remarkable enhanced photo-Fenton catalytic activity and stability.

Microwave-assisted fast synthesis of hierarchical NiCo2O4 nanoflower-like supported Ni(OH)2 nanoparticles with an enhanced electrocatalytic activity towards methanol oxidation

NiCo₂O₄/Ni(OH)₂ synthesizing through microwave-assisted hydrothermal method and coordination of homogeneous precipitation, exhibiting excellent electrocatalytic activity.

Nanosheets of NiCo2O4/NiO as Efficient and Stable Electrocatalyst for Oxygen Evolution Reaction

Development of a stable catalyst that can efficiently function for longer time for energy conversion process in water splitting is a challenging work. Here, NiCo₂O₄/NiO nanosheets are successfully synthesized following a simple wet-chemical route, followed by the combustion technique. Finally, the synthesized catalyst NiCo₂O₄/NiO can function as an efficient catalyst for oxygen evolution reaction. Nanosheets with interconnections are very useful for better electron transportation because the pores in between the sheets are useful for the diffusion of electrolyte in electrocatalysis. In oxygen evolution reaction, these sheets can generate current densities of 10 and 20 mA/cm², respectively, upon application of 1.59 and 1.62 V potential versus reversible hydrogen electrode (RHE) under alkaline condition. In contrast, bare NiCo₂O₄ nanowire bundles can generate a current density of 10 mA/cm² upon application of 1.66 V versus RHE. The presence of NiO in NiCo₂O₄/NiO nanosheets helps to increase the conductivity, which further increases the electrocatalytic activity of NiCo₂O₄/NiO nanosheets.

Facile Synthesis of Cu/NiCu Electrocatalysts Integrating Alloy, Core-Shell, and One-Dimensional Structures for Efficient Methanol Oxidation Reaction

The design and development of low-cost Pt-free, high-active, and durable noble-metal-free electrocatalysts for methanol electrooxidation is highly desirable but remains a challenge. Herein, unique Cu/NiCu nanowires (NWs) integrating alloy, core-shell, and one-dimensional structures are prepared by a facile one-pot strategy. It is found that the Ni-Cu surface alloying structure can effectively change the charge distribution of the atomic configuration, the core-shell structure can be optimized with the usage of Ni and Cu, and the one-dimensional structure can effectively enhance the charge transfer between the electrode surface and the active sites, making the prepared NWs promising electrocatalysts. Detailed catalytic investigations showed that the obtained Cu/NiCu NWs exhibit an enhanced electrocatalytic performance for methanol oxidation reaction (MOR). The optimized Cu/NiCu NWs in this work show a mass current density of 867.1 mA mg_metal^-1 at 1.55 V (vs. RHE) for MOR, which is far higher than those of Ni-based previously reported electrocatalysts. This work opens up a new pathway for the design and engineering of noble-metal-free alloy electrocatalysts with enhanced activity and durability.

Ag2S/Ag Heterostructure: A Promising Electrocatalyst for the Hydrogen Evolution Reaction

Different metal chalcogenides, being a potential candidate for hydrogen evolution catalysts, have attracted enormous attention in the field of water splitting. In the present study, Ag₂S/Ag is revealed as an efficient catalyst for hydrogen evolution. When a sacrificial template of the CuS nanostructure is used, Ag₂S/Ag heterostructures are synthesized following a simple wet-chemical technique. Two different routes, wet chemical and hydrothermal, are followed to modulate the morphology of the CuS templates from flower ball to wirelike structures, which subsequently results in the formation of Ag₂S nanostructure. Finally, the Ag layer is deposited on Ag₂S with the help of a photoreduction technique. The unique heterostructure of Ag₂S/Ag shows efficient catalytic activity in the H₂ evolution reaction. A Ag₂S/Ag wire can successfully generate a 10 mA/cm² current density at a -0.199 V potential. Ag₂S/Ag contains the micronanostructure where nanoplates of Ag₂S/Ag assemble to give rise to microstructures such as flower balls and wire.