Supporting effects of a N-doped carbon film electrode on an electrodeposited Ni@Ni(OH)₂ core–shell nanocatalyst in accelerating electrocatalytic oxidation of oligosaccharides

Abstract

The supporting effect of a N-doped carbon film induced superior crystallinity in electrodeposited Ni@Ni(OH)2 core–shell nanoparticles.

Vertically Oriented Metallic Heterodimer Array Semiembedded in Flat Conductive Carbon Film for Electrochemical Application

“…When the Ni­(OH) 2 NP is formed on the C film, Ni-core@Ni­(OH) 2 -shell NPs were formed with abundant grain boundaries (Figure S6), maybe because of rapid electrodeposition. This result is consistent with our previous report . Since the electron conductivity of Ni­(OH) 2 is very low (10 –17 S cm –1 ), the NiOOH formation reaction should occur at a part of the Ni­(OH) 2 shell attached or very close to the electron-conductive PdNP-C2 film surface.…”

“…This suggests that the Ni component of the heterodimer has a partially positive charge, which may make negatively charged molecules (glucose) easily accessible to its surface with the aid of electrostatic interactions. We speculate this may allow us to electrochemically oxidize glucose molecules with a small overpotential and high turnover rate . Moreover, the grain boundary-poor structure of the heterodimeric Ni­(OH) 2 NPs also contributes to enhancing electrocatalytic performances.…”

“…Nickel oxyhydroxide (NiOOH), which is formed by electrochemical oxidation of nickel hydroxide (Ni­(OH) 2 ) in alkaline solution, is known as a good electrocatalyst toward oxidation of organic molecules including alcohols and sugars. , The basic mechanism of electrocatalytic oxidation can be described as the following reactions …”

“…We speculate this may allow us to electrochemically oxidize glucose molecules with a small overpotential and high turnover rate. 45 Moreover, the grain boundary-poor structure of the heterodimeric Ni(OH) 2 NPs also contributes to enhancing electrocatalytic performances. When the Ni(OH) 2 NP is formed on the C film, Ni-core@Ni(OH) 2 -shell NPs were formed with abundant grain boundaries (Figure S6), maybe because of rapid electrodeposition.…”

“…This result is consistent with our previous report. 45 Since the electron conductivity of Ni(OH) 2 is very low (10 −17 S cm −1 ), 47 the NiOOH formation reaction should occur at a part of the Ni(OH) 2 shell attached or very close to the electron-conductive PdNP-C2 film surface. Then, the formed NiOOH may diffuse throughout the Ni(OH) 2 shell by oxidizing adjacent Ni(OH) 2 , in other words, by proton transfer from Ni(OH) 2 to NiOOH.…”