Nanoscale assembly and mechanism of K-Birnessite/GOs composite

Abstract

K-Birnessite was uniformly loaded on the surface of GOs via ion adsorption, in situ redox and in situ polymerization method using KMnO4 and MnSO4 as manganese sources to fabricate layered K-Birnessite/Graphene oxide (GOs) composites. The structure, micromorphology and element distribution of the composites were characterized by XRD, FTIR, Raman, FSEM and EDS. The results indicated that K-Birnessite obtained by Mn2+ and Mn7+ adsorbed on the surface of GOs via in situ redox reaction kept thinner slice structure and uniform distribution on the surface of GOs. The oxygen-containing functional groups bonded to GOs were reduced by Mn2+ with a decrease of structure defects of GOs and the self-assembled composites exhibited a graphite oxidize-like structure when K-Birnessite content was low. A complex compound was formed between K-Birnessite and GOs with the structure defects of GOs increased with increasing K-Birnessite content, which resulted in the disordered structure of the self-assembled composites. Keywords: Ion adsorption, Redox, Disordered structure, K-Birnessite/GOs, Compound mechanism