Enhanced photocatalytic reduction activity of uranium(vi) from aqueous solution using the Fe2O3-graphene oxide nanocomposite

• Published in: Dalton transactions : an international journal of inorganic chemistry 2017-11, Vol.46 (43), p.14762-1477
• Main Authors: Guo, Yadan, Guo, Yiqin, Wang, Xuegang, Li, Peng, Kong, Liuwei, Wang, Guanghui, Li, Xiaomeng, Liu, Yunhai
• Format: Article
• Language: English
• Subjects: Aqueous solutions; Catalysis; Catalytic activity; Chemical synthesis; Electron microscopy; Electron transfer; Electrons; Graphene; Hematite; Image resolution; Image transmission; Iron oxides; Kinetics; Nanocomposites; Nanoparticles; Photocatalysis; Reduction; Stability; Uranium; Wastewater treatment; X-rays
• ISSN: 1477-9226; 1477-9234
• DOI: 10.1039/c7dt02639k

Photocatalytic technologies are a potential solution for remediation of radioactive wastewater, including the reduction of radioactive hexavalent uranium, which is commonly found in wastewater from the nuclear industry. In this study, Fe 2 O 3 -graphene oxide composites were synthesized by an easy and scalable impregnation method as a catalyst for the reduction of U( vi ). X-ray photoelectron spectroscopy analysis and high-resolution transmission electron microscopy images of this composite clearly showed that the Fe 2 O 3 nanoparticles exist in the layered structure of graphene oxide. The photocatalytic activity of the Fe 2 O 3 -graphene oxide composite was evaluated by the reduction of U( vi ) to U( iv ) in aqueous solution under visible light. The results showed that the photocatalytic process of the Fe 2 O 3 -graphene oxide composite was always faster than that of the Fe 2 O 3 nanoparticles. Moreover, the experimental kinetic data for the catalytic process followed a pseudo-first-order model. The stability of the Fe 2 O 3 -graphene oxide composites was studied over successive experiments, with the photocatalytic reduction efficiency of U( vi ) decreasing to 76.0% after four cycles. Based on these experimental results, the enhanced photocatalytic activity and stability of Fe 2 O 3 -graphene oxide composites can be attributed to the improved adsorption properties of U( vi ) at GO and the electron transfer from iron oxide to GO. Photocatalytic technologies are a potential solution for remediation of radioactive wastewater, including the reduction of radioactive hexavalent uranium, which is commonly found in wastewater from the nuclear industry.