Revealing the role of graphene in enhancing the catalytic performance of phthalocyanine immobilized graphene/bacterial cellulose nanocomposite

The catalytic activity of metal phthalocyanine (MPc) heterogeneous catalyst is determined by both the microstructure of the support and the electron transfer efficiency of MPc during the reaction process. Inspired by this, we developed a novel, highly-efficient heterogeneous MPc catalyst based on the construction of a “reaction-involved” support. Graphene incorporated bacterial cellulose (G/BC) nanohybrid was conveniently prepared by an in situ biosynthetic method for the subsequent immobilization of tetraamino cobalt(II) phthalocyanine (CoPc) catalyst. The resulting graphene incorporated, CoPc decorated bacterial cellulose nanocomposite (CoPc@G/BC) was applied for decoloration of dye solutions, the G/BC support was deeply involved in the reaction process. The unique three-dimensional web-like framework structure of G/BC and the high affinity of graphene markedly promote the accessibility of reactants to the active sites of CoPc@G/BC, and the equilibrium adsorption data were best fitted by Freundlich model. With H 2 O 2 as an oxidant, dye molecules were catalytically oxidized by CoPc@G/BC, a ca. 70% enhancement of decoloration capacity was achieved with the incorporation of graphene. The catalytic oxidation was analyzed by electron paramagnetic resonance, highly reactive hydroxyl radical (·OH) was identified during the reaction, and the incorporated graphene can obviously promote the formation of ·OH. A potential mechanism of enhancement of catalytic activity of CoPc with G/BC support was originally proposed.