Fabrication of Novel Hierarchical β-Ni(OH)2 and NiO Microspheres via an Easy Hydrothermal Process

Abstract

Hierarchical β-Ni(OH) 2 microspheres with 6−8 μm diameter assembled from nanoplate/nanosheet building blocks were successfully fabricated via a hydrothermal process in the presence of an anion surfactant poly(ethylene glycol) 4-nonylphenyl 3-sulfopropylether potassium salt. The factors influencing the formation of hierarchical Ni(OH) 2 microspheres were monitored by using SEM characterizations. The effect of hydrothermal growth temperature on the Ni(OH) 2 morphology was also investigated. NiO microspheres assembled from nanoplate/nanosheet were also obtained by thermal decomposition of the as-synthesized β-Ni(OH) 2 at 320 °C for 3 h in air. HRTEM and SAED results reveal that the Ni(OH) 2 and NiO nanosheets are single crystalline. Nitrogen adsorption−desorption measurements of the BET surface area and pore size of NiO microspheres were 160 m 2 /g and 30−50 nm, respectively. It is anticipated that these novel hierarchical microsphere structures of Ni(OH) 2 and NiO will have great applications in Ni-based batteries, catalysis, and other potentials.