Ferrous Gluconate Participation Magnetic Carbon Microspheres And Complex Synthesis And Performance

In this paper, we reports a useful approach to achieve uniform magnetic graphite carbon spheres(MGCS) through synchronous hydrothermal treatment of ferrous gluconate and glucose followed by graphitizing the amorphous carbon at a high temperature. The results of SEM, TEM and XRD revealed that MGCSs with an average diameter of 1 um were synthesized; and magnetic Fe3O4 nanoparticles with diameters from 20 to 25 nm uniformly distributed in MGCSs. Meanwhile, a possible formation mechanisms of MGCS were proposed via the following steps. Firstly, the colloidal carbon spheres (CCSs) with uniformly dispersed Fe(II) and large numbers of hydroxyl groups were synthesized via synchronous hydrothermal reaction of glucose and ferrous gluconate. During the whole reaction, the spontaneous intermolecular dehydration, polymerization and cross-linking among glucouse and ferrous gluconate occurred due to the analogous molecular structure. As a result, Fe(II) disperse throughout the carbonaceous matrix of CCSs. Secondly, after separation and drying, the as-prepared CCSs were calcined under high-purity nitrogen stream. With the decomposition of organic gluconate and glucose during high temperature carbonization, only the adjacent Fe(II) aggregated to form small Fe3O4 nanoparticles due to the separation of carbonaceous matrix. When the temperature further increased, the amorphous carbon around Fe3O4 nanoparticles converted to graphitic carbon. Fe3O4 nanoparticles were enwrapped more compact. The strong confinement effect of the graphitic carbon not only can prevent the aggregation of magnetic Fe3O4 nanoparticles, but also can keep the stability of MGCSs in the solution. In addition, the diameter of the carbon spheres can be adjusted by the hydrothermal reaction condition, such as temperature, time of reaction, and concentration. Synchronously, the MGCSs not only have well adsorbing property as carbon materials, but also possess unusual adsorbing behaviour for heavy metal ions and noble metal ions, which have a significant potential application in the treatment of polluted water and the recovery of noble metal.As mentioned above, there are abundant functional groups on the surface of CCSs resulting from the hydrothermal carbonization, which also provide excellent support to synthesize composite microspheres. The hydroxyl groups of the as-prepared CCSs were also utilized to adsorb Ag+, Ce4+, Zr4+ ions or condensate with Ti-OH. Following a thermal treatment, composite MGCS@Ag or MGCS@TiO2(CeO2, ZrO2) were fabricated. Thereinto, composite MGCS@Ag exhibited excellent properties in antibacterial activity, composite MGCS@TiO2(CeO2, ZrO2) microspheres promising candidates for the enrichment of phosphopeptides and then magnetic-assist separation.