Preparation of graphene oxide composite nitrogen-doped carbon (GO@NCs) by one-step carbonization with enhanced electrosorption performance for U(VI)

Abstract

High-performance graphene oxide composite nitrogen-doped carbon (GO@NCs) materials were prepared at different temperatures (600, 700 and 800 °C) by a one-step carbonization method. The electrosorption performances of GO@NCs for U(VI) were investigated. The results showed that the specific surface area of GO@NC-700 was 266.3 m2·g−1. The doped nitrogen mainly existed in the form of pyridine (N-6), pyridine (N-5), and quaternary-N (N-Q). The incorporation of nitrogen atoms and graphene oxide effectively improved the electrochemical performance of the material, and the maximum specific capacitance of GO@NC-700 was 289.8 F·g−1. At the same time, nitrogen-containing functional groups improved the selectivity to uranium and weakened the repulsive effect of coexisting ions. Therefore, the removal efficiency of GO@NC-700 electrode structure can reach 98.63 % at −1.2 V (vs. SCE, pH = 5). The maximum adsorption capacity of GO@NC-700 was 879.2 mg·g−1, which was 4 times higher than that of simple adsorption (202.3 mg·g−1). The material had good cycle performance, and the capacity loss was less than 10 % after 5 cycles. The above results show that the GO@NC-700 electrode had special potential applications in removing uranium from aqueous solutions, which provides a new and effective method for the treatment of uranium-containing wastewater. Environmental implicationGraphene oxide composite nitrogen-doped carbon (GO@NCs) can effectively separate uranium (VI) from the solution and reduce its threat to the environment and human body.