Nature of the Synergistic Effect of N and S Co-Doped Graphene for the Enhanced Simultaneous Determination of Toxic Pollutants

• Published in: ACS applied materials & interfaces 2019-11, Vol.11 (47), p.44545-44555
• Main Authors: Zhu, Weiqing, Gao, Juanjuan, Song, Haiou, Lin, Xuezhen, Zhang, Shupeng
• Format: Article
• Language: English
• Subjects: Aniline Compounds - analysis; Catalysis; Electrochemical Techniques - instrumentation; Electrochemical Techniques - methods; Environmental Pollutants - analysis; Graphite - chemical synthesis; Graphite - chemistry; Limit of Detection; Nitrobenzenes - analysis; Nitrogen - chemistry; Phenylenediamines - analysis; Sulfur - chemistry
• ISSN: 1944-8244; 1944-8252
• DOI: 10.1021/acsami.9b13211

N-doped graphene (NG), S-doped graphene (SG), and N and S co-doped graphene nanocatalysts with different doping sequences (N-SG and S-NG) are successfully synthesized by a facile low-temperature hydrothermal method. By changing the synthetic sequence, S-NG significantly increases the electron transport rate of the sensor and the electrocatalytic ability compared to NG, SG, and N-SG due to the optimal proportion of doping element content and suitable N- and S-bonding configurations. The origin of the synergistic effect of N and S co-doped graphene is confirmed. Traces of S doping greatly enhance the electrochemical performance. The large volume of S-Ox groups may prevent the analytes from approaching the catalytic sites of the sensing materials due to a steric hindrance effect. S-NG, which possesses less S-Ox groups, exhibits better performance than N-SG. Pyridinic N plays an important role in enhancing the electrochemical activity and conductivity. The simultaneous determination of aniline (AN), p-phenylenediamine (PPD), and nitrobenzene (NB) as typical toxic pollutants is performed by employing the S-NG nanoarchitecture. The detection limits (S/N = 3) for AN, PPD, and NB are 0.023, 0.051, and 0.216 μM, respectively. In addition, the S-NG sensors also have excellent anti-interference, stability, and reproducibility. The precise control and synthesis of multiheteroatoms into graphene represent a promising strategy to enhance the electrocatalytic performance in energy and environmental fields.