Simple Preparation of Ni and NiO Nanoparticles Using Raffinate Solution Originated from Spent NiMH Battery Recycling

Abstract

Nickel (Ni) and nickel oxide (NiO) nanoparticles were produced by a combination of precipitation and reduction/calcination methods using the raffinate solution originated from laboratory scale spent NiMH recovery process. Ni recovery from the solution reached 99.8% by a simple precipitation step using baking soda. X-ray diffraction, FTIR spectroscopy, carbon analyzer and thermal gravimetric analysis techniques were used to characterize the precipitate. Metallic and oxide nanoparticles were obtained by hydrogen reduction and calcination under air atmosphere of the precipitate at 400 °C, respectively for 30-90 min residence times. The crystal structure, crystallite size, morphology, particle size and surface area of the samples, as well as carbon residue content in the particles were detected by particle characterization methods. The results indicate that spherical Ni nanoparticles have a crystallite size about 37 nm, and particle sizes of around 100 nm. The agglomeration of the nanoparticles reduces by increasing residence time. NiO nanoparticles have finer crystallite and particle sizes than the metallic samples produced at the same temperature and residence times. The results show that the combination of the simple methods presented can be an alternative process for producing advanced particles from spent NiMH batteries.

Fabrication of p-NiO/n-TiO2 Solar Device for Photovoltaic Application

“…NiO nanoparticles have a crystallite size of 15.6 nm. This compares favourably with 21.0 nm obtained from a heat treatment [34] compared to 37.0 nm obtained from raffinate solution [35].…”

NiO/Ni Nanowafer Aerogel Electrodes for High Performance Supercapacitors

“…NiO nanoparticles exhibit p-type semiconductivity with a band gap ranging from 3.6 to 4.0 eV [ 25 ]. Owing to their enhanced activity and superior physicochemical properties, NiO particles are used as electrode materials for supercapacitor applications, in addition to various other applications, such as catalysts, active materials in Li-ion batteries, removal of heavy metals from wastewater, electronic devices, and sensors [ 26 , 27 , 28 ]. The flaky NiO on stainless steel substrates obtained via electrochemical synthesis has exhibited good capacitance and has been employed in supercapacitor electrodes [ 29 ].…”

Suaeda maritima (L.) Dumort GREEN SYNTHESIS- REDUCED NICKEL OXIDE NANOPARTICLES FOR ANTIOXIDANT AND BACTERICIDAL ACTIVITY

“…Strong bond at 1749 cm -1 , 1581 cm -1, and 1269 cm -1 correspond to C-H bending, C=C stretching, and C-N stretch vibrations in aromatic compounds (Mude et al, 2009;Wang et al, 2014). The intense band at 705cm -1 can be associated with Ni-O-H bending and Ni-O stretching vibration in NiO NPs (Ebin, 2018). The metal-oxygen (Ni-O) stretching frequency of the synthesized NPs was identified by the presence of an intense peak at 978 cm -1 (Suresh et al, 2016).…”