Electrochemically Tuned Synergistic Nano‐Interface of a Tertiary Ni(OH)₂−NiO(OH)/Ni_xP Heterojunction Material for Enhanced and Durable Alkaline Water Splitting

Abstract

Making water splitting cheaper is the need of the hour.The present work reports a nickel‐based, non‐precious catalytic system, synthesized by a two‐step electrodeposition (ED) process followed by a short‐term heat treatment. The Ni(OH)2−NiO(OH)/NixP heterojunction has been synthesized and optimized through an unprecedented, energy‐conserving method to achieve its best OER performance. Further, it has been carefully tuned for the first time by thoroughly optimizing the ED parameters to exhibit Hydrogen Evolution Reaction (HER). At high current regimes, the performance surpassed that of the Ru/C and Pt/C (≥500 mA and ≥600 mA) respectively. The full cell electrolyzer configuring NOPO||NOPH further establishes the supremacy of the present electrocatalysts over the benchmark Ru/C||Pt/C. Moreover, the present electrocatalyst displayed 60 and 70 hours of HER and OER performances at −100 mA and 100 mA currents respectively. In short, this work is an example that illustrates how a single chemical system gets to exhibit two complementary catalytic behaviors that is, water oxidation and reduction when certain synthetic parameters are meticulously optimized.

Electrochemical Quantification of Tyrosine in the Presence of Analogous Amino Acids

“…Due to its extensive modulation range of electro-chromic activity it acts as efficient electron mediator in electrochemical sensors based on the outstanding catalytic future of the Ni(II)/Ni(III) redox system. [60][61][62][63][64][65][66][67][68][69][70]…”

“…High porosity, high surface/volume ratio, and morphology caused NiO NPs to have suitable electrochemical sensing. Due to its extensive modulation range of electro‐chromic activity it acts as efficient electron mediator in electrochemical sensors based on the outstanding catalytic future of the Ni(II)/Ni(III) redox system [60–70] …”

The Experimental Design Approach in Square‐Wave Voltammetric Determination of Tamoxifen by NiO‐CPE**

“…Thus, NiO NPs, as the electrochemical sensor, act as efficient electron mediators due to the unusual catalytic activity of the Ni(II)/Ni(III) redox system. Finally, NiO has been widely used for constructing fuel and solar cells (dye-sensitized solar cells), gas sensors, electrochemical sensors, adsorbents, supercapacitor materials, anodic materials in Li-ion batteries, transparent electrodes, photocatalyst, etc.. [55][56][57][58][59][60][61][62][63] Optimization is a method in which the highest overall process efficiency could be achieved with no increase in the cost by choosing the best elements from sets of influencing alternatives, called independent variables) On the other hand, the best characteristics and performances can be reached under optimized conditions. Two well-known optimization methods are OFAT and DOE methods.…”

“…Finally, NiO has been widely used for constructing fuel and solar cells (dye‐sensitized solar cells), gas sensors, electrochemical sensors, adsorbents, supercapacitor materials, anodic materials in Li‐ion batteries, transparent electrodes, photocatalyst, etc. [55–63] …”