Structurally Engineered Anisotropic Cobalt‐Based Nanostructures for Efficient Chlorine and Oxygen Evolution

Abstract

Electrochemical Cl2 generation using inexpensive electrocatalysis has drawn tremendous scientific attention to meet the future demand for chlorine. The present work deals with the design of the chemical process to synthesize anisotropically aligned metallic hcp‐cobalt nanoparticles. The as‐obtained hcp‐cobalt rods are utilized for the generation of O2 and Cl2 via an electrochemical process. Controlling the thermodynamic parameters during the thermal decomposition of cobalt oxalate rods leads to the formation of aligned nanoparticles. Detailed microscopic investigation shows that the slow heating rate favors the anisotropic growth of nanoparticles, and the fast‐heating rate leads to the formation of agglomerated nanoparticles. Anisotropically aligned hcp‐Co rods show an overpotential of 240 and 30 mV for O2 and Cl2 evolution, respectively. These findings elaborate that aligned particles (rod‐like structures) show promising electrocatalysts with better efficiency for O2 and Cl2 generation. Further, wastewater treatment is done by using in situ generated chlorine and 99% degradation efficiency is observed for textile effluents (methyl orange).

Recent advances in energy-efficient chlorine production via HCl electrolysis

“…Although plenty of catalysts such as IrO 2 –TiO 2 NSA, 74 Ti/RuO 2 needles, 75 flower-like RuO 2 –TiO 2 , 76 Ti 0.35 V 0.35 Sn 0.25 Sb 0.05 -oxide, 77 Co 3 O 4 NBAs, 78 and hcp-cobalt rods 79 have been explored for chlorine evolution from NaCl, but there are limited works on electrode materials for HCl electrolysis. RuO 2 /TiO 2 is a state-of-art catalyst for chlorine evolution that has been utilized for chlorine electrolysis; there is still a reliance on noble metals.…”

Modulation of electrocatalytic activity by tuning anion electronegativity: case study with copper chalcogenides

“…The chalcogens in the compounds form strong covalent bonds with the metal atoms, which renders the compounds resistant to corrosion or degradation. Improvements in electrocatalyst performance have been proposed through the use of a wide range of control mechanisms, including the development of hierarchical structures, the doping of heteroatoms and the processing of alloys [17,[22][23][24][25]. Few studies have also investigated the effect of anion species on the performance of water splitting electrocatalysts [16,18,[26][27][28].…”