An Efficient Emulsion-Induced Interface Assembly Approach for Rational Synthesis of Mesoporous Carbon Spheres with Versatile Architectures

Abstract

Mesoporous carbon matrix with open pore structure, short diffusion length, and large pore size can favor the in-pore immobilization of active species and facilitate mass diffusion during catalytic reactions. However, a great difficulty still remains on controllable synthesis of uniform mesoporous carbon spheres with these structural characteristics. Herein, using amphiphilic Pluronic F127 as the surfactant, 1,3,5-trimethyl benzene (TMB) as the pore swelling and interface-adjusting agent, and dopamine as the carbon source, a robust emulsion-induced interface assembly approach for rational synthesis of mesoporous carbon spheres is demonstrated. The interface assembly process, including dopamine polymerization and fusion of TMB/F127/dopamine emulsions, can be regulated by tuning the dosage of dopamine and ammonia water, resulting in mesoporous carbon spheres with tunable pore sizes and versatile architectures, such as vesicles, walnut shapes, spheres with dendritic-like 3D radially aligned mesochannels (RA-MC), and isolated spherical mesopores. Moreover, the derived RA-MC is used as a promising matrix to immobilize ultra-small Au nanoparticles (≈3 nm). The Au/RA-MC exhibits no mass diffusion limitations in reduction of 4-nitrophenol, showing high conversion efficiency and good recyclability. This work paves a new avenue for controllable synthesis of mesoporous carbon spheres with well-developed mesoporosity and architectures and their application as novel heterogeneous catalysts.