Synthesis of nickel hydroxychloride microspheres via a facile template-free process and their conversion to β-Ni(OH)2 microspheres

Abstract

Hierarchical flower-like nickel hydroxychloride microspheres were prepared by forced hydrolysis reaction of nickel chloride hexahydrate in ethanol via a facile template-free solvothermal process. The flower-like nickel hydroxychloride microspheres, which were prepared with low concentration of Ni without adding H₂O, were composed of crumpled nanosheets with random orientation. The aggregation growth and the dissolution–recrystallization process were involved in the formation of the flower-like nickel hydroxychloride microspheres. The flower-like β-Ni(OH)₂ microspheres were prepared by nickel hydroxychloride microspheres treated with high concentration of KOH. The β-Ni(OH)₂ microspheres prepared with higher concentration of KOH showed better electrochemical performance, while the β-Ni(OH)₂ microspheres prepared with lower concentration of KOH showed better adsorption activity for acid fuchsine.