Electron transfer enhanced catalytic activity of nitrogen doped reduced graphene oxide supported CuCoO towards the fast reduction of 4-nitrophenol in water.

There has been a growing interest in the design and development of graphene based composite materials with superior performances for environmental catalytic applications. But in most of the studies the synthesis conditions require elevated temperatures and expensive working setups (high temperature furnaces, autoclaves, inert atmosphere conditions etc.). In this reported work, the nitrogen doped reduced graphene oxide supported CuCoO (NG/CuCoO) composites were prepared through a simple one pot synthesis method under mild conditions (∼95 °C and air atmosphere) and successfully employed as catalysts for the reduction of toxic 4-nitrophenol (4NP). The characterization results revealed the successful formation of NG/CuCoO composites with a possible charge transfer interaction between nitrogen doped reduced graphene oxide support of CuCoO. The NG/CuCoO hybrids exhibited robust catalytic activity in 4NP reduction with an activity factor of 261.5 min g. A 4NP conversion percentage which is as high as 99.5% was achieved within 11 min using the NG/CuCoO catalyst. The detailed kinetic analysis confirmed the Langmuir-Hinshelwood model for the NG/CuCoO catalysed 4NP reduction. The nitrogen doped reduced graphene oxide support modified the electronic levels of CuCoO nanoparticles through electron transfer interactions and enhanced the catalytic activity of CuCoO in NG/CuCoO through improved adsorption of reactant ions and effective generation of active hydrogen species. The good reusability and stability along with profound activity of NG/CuCoO catalyst makes it a promising material for wide scale catalytic applications.