Application of electroactive Au/aniline tetramer-graphene oxide composites as a highly efficient reusable catalyst

• Published in: RSC advances 2021-01, Vol.11 (1), p.71-77
• Main Authors: Lai, Guan-Hui, Chou, Yi-Chen, Huang, Bi-Sheng, Yang, Ta-I, Tsai, Mei-Hui
• Format: Article
• Language: English
• Subjects: Aminophenol; Aniline; Catalysts; Chemical synthesis; Chemistry; Clean energy; Composite materials; Electrons; Fourier transforms; Gold; Graphene; Nanoparticles; Nitrophenol; Photoelectrons; Spectrum analysis
• ISSN: 2046-2069; 2046-2069
• DOI: 10.1039/d0ra08535a

This study proposes a cost-effective, energy-saving, and green process that uses π-π interactions to modify graphene oxide (GO), and the conjugate structure of aniline tetramer (AT) to enhance the dispersion of GO. Au/aniline tetramer-graphene oxide (Au/ATGO) composites were synthesized and applied as a catalyst in this study. The adsorption of AT on GO, via π-π interaction, formed ATGO composites. Subsequently, the amine group on ATGO was stably anchored on Au nanoparticles (Au NPs) to form Au/ATGO composites. The Au/ATGO composites were characterized and the electroactive properties determined by Fourier-transform infrared spectroscopy, X-ray photoelectron spectroscopy, transmission electron microscopy, and cyclic voltammetry. The Au/ATGO composites showed excellent performance and stability as catalysts when applied for the reduction of nitrophenol to aminophenol within 225 s and the rate constant was 0.02 s −1 . The activation energy for the reduction of 4-NP and 2-NP was 48.10 and 68.71 kJ mol −1 , respectively. Following a recycling test repeated 20 times, the Au/ATGO composites maintained a conversion rate higher than 94%. The stable and reusable Au/ATGO composites were prepared. Aniline tetramer not only modified GO but also can anchor Au NPs. The Au/ATGO composites as a catalyst exhibit good cycling stability.