Nanostructured Alpha-Nickel Hydroxide Electrodes for High Performance Hydrogen Peroxide Sensing

One material, multiple functions: graphene/Ni(OH)2 thin films applied in batteries, electrochromism and sensors

Different nanocomposites between reduced graphene oxide (rGO) and Ni(OH)₂ nanoparticles were synthesized through modifications in the polyol method (starting from graphene oxide (GO) dispersion in ethylene glycol and nickel acetate), processed as thin films through the liquid-liquid interfacial route, homogeneously deposited over transparent electrodes and spectroscopically, microscopically and electrochemically characterized. The thin and transparent nanocomposite films (112 to 513 nm thickness, 62.6 to 19.9% transmittance at 550 nm) consist of α-Ni(OH)₂ nanoparticles (mean diameter of 4.9 nm) homogeneously decorating the rGO sheets. As a control sample, neat Ni(OH)₂ was prepared in the same way, consisting of porous nanoparticles with diameter ranging from 30 to 80 nm. The nanocomposite thin films present multifunctionality and they were applied as electrodes to alkaline batteries, as electrochromic material and as active component to electrochemical sensor to glycerol. In all the cases the nanocomposite films presented better performances when compared to the neat Ni(OH)₂ nanoparticles, showing energy and power of 43.7 W h kg⁻¹ and 4.8 kW kg⁻¹ (8.24 A g⁻¹) respectively, electrochromic efficiency reaching 70 cm² C⁻¹ and limit of detection as low as 15.4 ± 1.2 μmol L⁻¹.

Facile synthesis of CeO2decorated Ni(OH)2hierarchical composites for enhanced electrocatalytic sensing of H2O2

CeO₂–Ni(OH)₂composites with hierarchical structures were synthesizedviaa facile one-pot hydrothermal method, which were constructed with Ni(OH)₂nanosheets decorated within situformed CeO₂nanoparticles on their surface.