Construction of three-dimensional polyethyleneimine incorporated graphene oxide aerogels as high-capacity electrode for enhanced uranium(VI) electrosorption performance

Abstract

Electrosorption technique is paid more attention in recovery of uranium(VI) due to its low energy consumption, green process and easy regeneration, but still is hindered by the limited accessible active sites on the electrode material, poor surface wettability and inherent ion exclusion effects. Herein, novel there dimensional porous polyethyleneimine/graphene oxide aerogel (PEI/GOA) electrode was constructed by incorporating polyethyleneimine into graphene oxide and using chitosan as binder for uranium(VI) electrosorption. The synthesized PEI/GOA had a stable three-dimensional porous structure, high specific capacitance (54.06F/G) and good charge–discharge stability. The electrosorption process of uranium(VI) by PEI/GOA electrode was affected by applied voltage and pH, fitted by the pesuo-second-order kinetics and Langmuir model. The maximum theoretical electrosorption capacity of uranium(VI) by PEI/GOA electrode at − 1.2 V was 419.71 mg/g, which was 2.2 times higher than that of pure graphene oxide electrode. PEI/GOA electrode exhibited less than 20 % loss after five cycles using 0.1 M NaHCO3 as the eluent. The efficient U(VI) electrosorption by PEI/GOA electrode was not only attributed to the formation of the electric double layer, but also due to the interaction and synergy of the –NH2, –CONH- and –OH on the PEI/GOA electrode. This research offers a new approach for the efficient removal of uranium (VI) from uranium-containing wastewater.