Combination of Redox Assembly and Biomimetic Mineralization To Prepare Graphene-Based Composite Cellular Foams for Versatile Catalysis

Graphene-based materials with hierarchical structures and multifunctionality have gained much interest in a variety of applications. Herein, we report a facile, yet universal approach to prepare graphene-based composite cellular foams (GCCFs) through combination of redox assembly and biomimetic mineralization enabled by cationic polymers. Specifically, cationic polymers (e.g., polyethyleneimine, lysozyme, etc.) could not only reduce and simultaneously assemble graphene oxide (GO) into cellular foams but also confer the cellular foams with mineralization-inducing capability, enabling the formation of inorganic nanoparticles (e.g., silica, titania, silver, etc.). The GCCFs show highly porous structure and appropriate structural stability, where nanoparticles are well distributed on the surface of the reduced GO. Through altering polymer/inorganic pairs, a series of GCCFs are synthesized, which exhibit much enhanced catalytic performance in enzyme catalysis, heterogeneous chemical catalysis, and photocatalysis compared to nanoparticulate catalysts.