Structural and mechanistic understanding of an active and durable graphene carbocatalyst for reduction of 4-nitrophenol at room temperature

• Published in: Nano research 2015-12, Vol.8 (12), p.3992-4006
• Main Authors: Hu, Huawen, Xin, John H., Hu, Hong, Wang, Xiaowen
• Format: Article
• Language: English
• Subjects: Aids; Ambient temperature; Aminophenol; Ascorbic acid; Atomic/Molecular Structure and Spectra; Biomedicine; Biotechnology; Catalysis; Catalysts; Catalytic activity; Chemistry and Materials Science; Condensed Matter Physics; Depletion; Durability; Graphene; Heavy metals; Materials Science; Nanostructure; Nanotechnology; Nitrophenol; Rare resources; Reduction; Research Article; Room temperature; Structural analysis; Synergistic effect; Water pollution; 室温; 对硝基苯酚; 机理; 氧化石墨; 活性物种; 结构特征; 耐用; 还原
• ISSN: 1998-0124; 1998-0000
• DOI: 10.1007/s12274-015-0902-z

The development of an active, durable, and metal-free carbocatalyst that is able to replace metal-based catalysts is of increasing scientific and technological importance. The use of such a catalyst would avoid problems caused by metal- containing catalysts, for example, environmental pollution by heavy metals and depletion of rare metal resources. Herein, an active and durable graphene carbocatalyst is presented for the carbocatalytic conversion of 4-nitrophenol to 4-aminophenol at ambient temperature. The carbocatalyst was prepared via a mild, water-based reaction between L-ascorbic acid （AA） and graphene oxide （GO） and did not involve any other reactants. During the structure and catalytic property optimization, a series of carbocatalysts were fabricated at various reaction temperatures and AA/GO ratios. Using several characterization techniques, detailed structural features of these carbocatalysts were identified. Possible active species and sites on the carbocatalysts were also identified such as certain oxygen-containing groups, the ~x-conjugated system, and graphene sheet edges. In addition, the synergistic effect between these active species and sites on the resulting catalytic activity is highlighted. Furthermore, we clarified the origin of the high stability and durability of the optimized carbocatalyst. The work presented here aids the design of high-performance carbocatalysts for hydrogenation reactions, and increases understanding of the structural and mechanistic aspects at the molecular level that lead to high catalyst activity and durability.