Si-Doped Nitrogenated Holey Graphene (C<sub>2</sub>N) as a Promising Gas Sensor for O-Containing Volatile Organic Compounds (VOCs) and Ammonia
oleh: Yang Liu, Chenxiao Ye, Hengxin Zhao, Kexin Lin, Xinrui Cao, Yuejie Ai
| Format: | Article |
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| Diterbitkan: | MDPI AG 2023-05-01 |
Deskripsi
Two-dimensional (2D) crystalline materials have been regarded as promising sensor materials due to their large specific surface area, high sensitivity, and low cost. In the present work, based on the density functional theory (DFT) method, the sensor performance of novel silicon (Si)-doped nitrogenated holey graphene (SiC<sub>2</sub>N) toward five typical VOCs (HCHO, CH<sub>3</sub>OH, C<sub>3</sub>H<sub>6</sub>O, C<sub>6</sub>H<sub>6</sub>, and C<sub>2</sub>HCl<sub>3</sub>) and ammonia were systematically investigated. The results demonstrated that Si doping could effectively decrease the band gap of C<sub>2</sub>N and simultaneously provide active sites for gas adsorption. Through comprehensive analyses of adsorption energies and electronic properties, the SiC<sub>2</sub>N was found to exhibit high selectivity for O-containing VOCs (HCHO, CH<sub>3</sub>OH, and C<sub>3</sub>H<sub>6</sub>O) and NH<sub>3</sub> via a covalent bond. Moreover, after the HCHO, CH<sub>3</sub>OH, C<sub>3</sub>H<sub>6</sub>O, and NH<sub>3</sub> adsorption, the band gap of SiC<sub>2</sub>N greatly decreases from 1.07 eV to 0.29, 0.13, 0.25, and 0.12 eV, respectively, which indicated the enhancement the conductivity and enabled the SiC<sub>2</sub>N to be a highly sensitive resistive-type sensor. In addition, the SiC<sub>2</sub>N possesses a short recovery time. For instance, the recovery time of HCHO desorbed from SiC<sub>2</sub>N is 29.2 s at room temperature. Our work anticipates a wide range of potential applications of Si-doped C<sub>2</sub>N for the detection of toxic VOCs and ammonia, and supplies a valuable reference for the development of C<sub>2</sub>N-based gas sensors.