Preparation And Analysis Of Nickel-based Magnetic Activated Carbon By Electroless Plating

Activated carbon has been widely used because of its interesting properties such as its porosity and high specific surface area, which are interesting characteristics in adsorption and in supported catalysis. However, the electromagnetic properties of untreated activated carbon are poor. It can be expected that if the activated carbon were coated with a layer of metal, wider use would be developed in some fields, such as conducting activated carbon, which has some advantages of good conductivity, high intensity, low price and a good combination of characteristics, as the materials could combine the properties of activated carbon and the metal together.Based on the above thoughts, nickel-based magnetic activated carbon was prepared from coconut shell activated carbon by electroless plating with palladium-free activation. The effects of various parameters during the processing were investigated in the paper. The surface areas and total pore volumes are determined. And the adsorbents generated were subjected to adsorption tests in the liquid phase using both methylene blue and iodine as adsorbates to be retained. In this way, adsorption capacities of the two adsorbates were analysed. The appearances of the activated surface on the carbon and the deposited Ni-P layer were characterized by Scanning Electron Microscopy (SEM). The components on the substrate surface after activating and electroless plating were investigated by Energy Dispersive Spectroscopy (EDS). The powder is expected to possess the advantages common to both activated carbon and metal powder. The magnetic and microwave absorber properties of the powder were studied.The main content and conclusions of this thesis are described as follows:The optimal conditions of electroless plating niekel alloy coated activated carbon are temperature 70C, pH 8-9 and the particle size of the activated carbon is 200-400 mesh. The nickel-based activated carbon showed high adsorption capacity for methylene blue and iodine number. The value of them can achieve 142.5 mg/g and 1035 mg/g, respectively. The metallic ratio is increased with the increase of the plating solution volume. The specific area and pore volume decreased from 942.86 m2/g to 859.12 m2/g and 0.462 mL/g to 0.417 mL/g, respectively. The magnetic properties are increased with the increase of the metallic ratio.By electroless Plating, the surface of the activated carbon was covered by a Ni-P coating, which was uniform, compact, and continuous and had an obvious metallic sheen. The content of P and Ni was 2.73% and 97.27% in the coating. Compared with the untreated activated carbon, the real permeabilityμ' and imaginary permeabilityμ" of Ni-based activated carbon became greater, whereas the real permittivityε'and imaginary permittivityε" became smaller. Also, the plated activated carbon was magnetic, making it suitable for some special applications. In general, the method reported here might be a feasible procedure to coat activated carbon with other magnetic metals, which may find application in various areas.