Controllable preparation of reduction graphene oxide materials with designated oxygen percentages and energy levels by catalysts

Abstract

Desired reduced graphene oxide materials should exhibit designed molecular orbital energy levels or oxygen contents. Up to date, a method of preparing desired functional materials based on RGO with designed molecular orbital energy levels or oxygen contents has not been reported. In this paper, metal oxides, such as Al₂O₃, Bi₂O₃, TiO₂, WO₃, MoO₃ and ZnO, with a variety of the lowest unoccupied molecular orbital (LUMO) energy level (E_LUMO) values were used as catalysts to reduce graphene oxide (GO) under light irradiation to generate light reduction graphene oxide (LRGO) materials, which have different percentages of oxygen and the E_LUMO values. Experimental results showed that E_LUMO values of the functional LRGO materials depended on E_LUMO values of the metal oxide catalysts. In order to improve application of the investigation in syntheses of functional reduced-graphene-oxide materials with designed E_LUMO value or designed oxygen content, relationship between the E_LUMO values and oxygen contents of the functional reduced-graphene-oxide materials was studied. The investigation result showed that the E_LUMO values of the functional LRGO materials are negative correlation with their percentages of oxygen. Therefore, this paper suggests a novel and effective method of preparing reduced-graphene-oxide with designed E_LUMO value or designed oxygen percentages by added catalysts.