Inspiring the potential of graphene oxide aerogel for uranium(VI) electrosorption: A precursor reconfiguration strategy and synergistic integration with polyethyleneimine

Nitrogen-doping of graphene oxide can significantly enhance its electrochemical and electrosorption performances for uranium(VI). The conventional methods of N-doping such as hydrothermal and pyrolytic processes invariably cause a significant loss of surface groups, which are not conducive to further functionalization of graphene oxide with other polymers by means of chemical bonds. Herein, a novel N-doped graphene oxide was first prepared using graphite by a precursor reconfiguration strategy, and then used as the precursor to construct a self-supported N-doped graphene oxide aerogel (PNGOA) by freeze drying technique. The prepared PNGOA exhibited larger specific surface area, better hydrophilicity, more structural defects, superior electrochemical and electrosorption performances. Next, the hydrophilic polyethyleneimine (PEI) was integrated into PNGOA to synthesis the N-doped graphene oxide aerogel/polyethyleneimine (PNGOA/PEI) electrode in order to further enhance the electrosorption of uranium(VI). The assessed theoretical maximum uranium(VI) electrosorption capacity by the PNGOA/PEI electrode was determined to be 680.89 mg/g, which was twice that of graphene oxide aerogel/polyethyleneimine (GOA/PEI) electrode. PNGOA/PEI aligned more closely with pseudo-second-order kinetic and Langmuir model. The effective electrosorption of U(VI) by the PNGOA/PEI electrode benefits from the improvement of electrochemical properties of graphene oxide due to its N-doping by a precursor reconfiguration strategy, and the synergistic interactions between the NH 2 , CONH , and OH groups from PEI with uranium(VI) on the PNGOA/PEI electrode. This work greatly inspired the potential of graphene oxide aerogel via an innovative method for effectively eliminating uranium(VI) from wastewater contaminated with uranium. • Self-supported N-doped precursor derived graphene oxide aerogel was constructed by precursor reconfiguration strategy. • The N-doping of precursor could significantly enhance the physical and electrochemical properties of aerogel. • PEI was synergistically integrated into aerogel for enhanced electrosorptive removal of U(VI) reaching 680.89 mg/g. • Simple precursor reconfiguration strategy and the integration of PEI inspired the potential of aerogel.