Facile Synthesis of Co‐Al and Ni‐Al Layered Double Hydroxide for Applications in Energy and Environment

Layered double hydroxides are a well‐known material due to their application in various fields, including adsorbents, catalysis, molecular sieves, etc. The applications of these materials are associated with their unique positive layered structure with intercalated anions. Facile and scalable synthesis of these materials also increases their utility of these materials for practical applications. Inspired by these unique properties, in this work, two different layered double hydroxides were synthesized by the co‐precipitation method using Co‐Al and Ni‐Al as metal combinations. Prepared layered double hydroxides were characterized by X‐ray diffraction and scanning electron microscopy equipped with energy‐dispersive X‐ray spectroscopy. Phase analysis was done by Rietveld refinement of X‐ray diffraction data. We explored the applications of these materials as sorbents to remove Cr(VI) from aqueous solutions, as a capacitor for charge storage and as a catalyst for electrochemical oxidation of water. Chromate ion adsorption by these materials follows Langmuir adsorption isotherm and pseudo‐second‐order kinetics. Removal efficiencies of Ni‐Al LDH and Co‐Al LDH for chromate ions are found to be 86% and 88%, respectively. Further, electrochemical measurements in the non‐Faradaic region indicate a capacitive nature of prepared material with a specific capacity of 0.205 F/g at a scan rate of 10 mV s −1 . Catalytic performance of the prepared catalyst has been investigated towards the oxygen evolution reaction in basic solution (0.1 M KOH). Among the prepared catalysts, Co‐Al catalyst exhibited a lower onset potential of 1.691 V as well as a Tafel slope of 122.89 mV dec − ¹. An one‐pot, easy synthesis, low‐cost, and multi‐dimensional application of these materials makes them fascinating in the field of energy as well as the environment.