Substituent Effects on Electronic Structures and Peroxidase-Mimicking Activities of Graphyne and Palladium-Doped Graphyne: A Computational Study

• Published in: Journal of physical chemistry. C 2020-05, Vol.124 (18), p.9917-9923
• Main Authors: Wang, Xiaoli, Gao, Xingfa
• Format: Article
• Language: English
• ISSN: 1932-7447; 1932-7455
• DOI: 10.1021/acs.jpcc.0c00542

The substituent effects on the electronic structures and peroxidase-mimicking activities of γ-graphyne (GY) and Pd-doped GY are studied by density functional theory calculations. Both the inductive and mesomeric effects of the substituents significantly influence the electronic structures of GY and its derivatives. However, the complexation strength between Pd atoms and GY is mainly affected by the long-range mesomeric effect rather than the short-range inductive effect of the substituents. The pristine GY hardly has peroxidase-mimicking activity because H2O2 molecules strongly chemisorb on the triple bonds in the form of hydroxyl groups. However, GY doped with Pd atoms, namely, Pd@GY, has greatly enhanced peroxidase-mimicking activity. The activity can be further tuned by decorating Pd@GY with external functional groups. The decorated groups alter not only the rate-limiting reaction steps of the catalysis but also the energies associated with the reactions. Pd@GY decorated with F atoms may have the largest peroxidase-mimicking activity among that of the substituents studied here. The results provide an in-depth understanding of the substituent effects on the electronic structures of GY and Pd@GY and suggest the potential of chemical functionalization in fine-tuning the peroxidase-mimicking activities of the materials.