Rational design of hierarchically-structured CuBi2O4 composites by deliberate manipulation of the nucleation and growth kinetics of CuBi2O4 for environmental applications.

A versatile, eco-friendly synthesis scheme was developed to fabricate a series of hierarchically-structured CuBi2O4 composites for environmental applications. By simple tuning of the synthesis protocol (i.e. controlling the ethylene glycol to water ratio in the reaction matrix and employing different auxiliary metal precursors consisting of Cu(2+), Co(2+) or Fe(3+) species), deposition of various metal oxides on CuBi2O4 was achieved. The proposed one-pot synthesis protocol utilizes the fast nucleation and controlled growth kinetics of CuBi2O4 to deliberately immobilize the desired metal oxides on the surface of the CuBi2O4. The manipulation of the diffusion rate, mass transfer kinetics and atomic mobility of the metal precursors by controlling the viscosity and dielectric properties of the reaction matrix lead to the formation of different CuBi2O4 composites with the desired properties. The synergistic coupling effect between the CuBi2O4 and deposited metal oxide contributed to the superior performance of the novel CuBi2O4 composites. The CuBi2O4 composites demonstrate excellent potential for various environmental applications such as being a catalyst for generating sulfate radicals from peroxymonosulfate for organic pollutant removal in water and being a disinfectant. The proposed green synthesis protocol is simple and offers flexibility for fabricating hierarchically-structured CuBi2O4 composites with enhanced properties for targeted applications.