Hierarchical Reduced Graphene Oxide-MnO2@ Polypyrrole Coaxial Nanotube Composite Hydrogel as a Potential Adsorbent for Cr(VI) Removal

• Published in: Journal of Wuhan University of Technology. Materials science edition Vol. 39; no. 5; pp. 1287 - 1293
• Main Authors: Liu, Ben, Xu, Yaowei, Tong, Yuxing, Wang, Ziwei, Liu, Zhichang, Yan, Qunshan, Ji, Jiayou, Gao, Song, Li, Shaoping
• Format: Journal Article
• Language: English
• Published: Wuhan Wuhan University of Technology 01.10.2024
• Subjects: Chemistry and Materials Science; Materials Science; Organic Materials; polypyrrole; Cr(VI) removal; hydrogel; graphene; MnO
• ISSN: 1000-2413; 1993-0437
• DOI: 10.1007/s11595-024-2996-1

A hierarchical reduced graphene oxide-MnO 2 @polypyrrole coaxial nanotube composite hydrogel was prepared via oxidative polymerization of pyrrole in the presence of MnO 2 nanotubes, followed by the hydrothermal treatment of graphene oxide and MnO 2 @polypyrrole coaxial nanotubes. The stable composite hydrogel with a hierarchical network was composed of one-dimensional MnO 2 @polypyrrole coaxial nanotube and two-dimensional graphene nanosheet and characterized by scanning electron microscope, Fourier transform infrared spectroscopy, X-ray diffraction, Brunauer-Emmett-Teller surface, and X-ray photoelectron spectroscopy measurements. The composite hydrogel can be used as an efficient adsorbent for Cr(VI) removal due to the synergistic interaction between graphene and MnO 2 @polypyrrole and the hierarchical structure of the hydrogel. Moreover, the composite hydrogel is easily separated because of its stable monolith, and it is reusable (76.8% of removal ability remaining after five adsorption-desorption cycles). The simple fabrication and cost-effective separation process together with the excellent absorption performance endow the composite hydrogel with great potential for practical wastewater treatment.