Adsorption of C2H2 on heteroatom-decorated graphene

• Published in: New journal of chemistry 2024-07, Vol.48 (26), p.11697-11704
• Main Authors: Cai, Tianzi, Zhang, Zilong, Gai, Xingyu, Zuo, Fangmin, Gao, Fengkai, Wang, Bolin, Zhang, Haifeng
• Format: Article
• Language: English
• Subjects: Acetylene; Adsorption; Chemical synthesis; Configurations; Decoration; Gas sensors; Graphene; Substrates
• ISSN: 1144-0546; 1369-9261
• DOI: 10.1039/d4nj01608d

There remains considerable debate over the adsorption mechanism of acetylene in transformer fault gas detection. Herein, a graphene-based gas sensor with distinct decorated N, B configuration was constructed and evaluated via DFT. The adsorption and activation of C2H2 can be better facilitated over B-decorated pyridinic N sites than that on graphitic N and pyrrolic N configurations, presenting the adsorption energies of −0.22, −0.17 and 0.16 eV, respectively. Electron localization function (ELF) configurations and Bader charge analysis indicate that the electronic interaction between the graphitic substrates and C2H2 maybe responsible for tuning C2H2 adsorption behavior since the electron acceptor C2H2 transfers 0.497, 0.459 and 0.206 e from B-decorated pyridinic N, graphitic N and pyrrolic N configurations, respectively. Compared with pyridinic-N/G, the modification by B destroys the π electron pair of graphene, which is not conducive to the activation of the graphene surface. Additionally, in the DOS analysis, there is a clear overlap between B and N atoms, confirming the favorable contribution of B atoms to the adsorption performance. Compared with the other two co-doping structures, the pyridinic N–B/G structure has a higher p-band center, ensuring superior adsorption and activation capabilities for C2H2 during the reaction process. Significant contributions have been made by this research to the application of non-metal-doped graphene materials in gas sensor devices and the synthesis of highly efficient catalysts.