Lv Ya-Kun, Li Yan-Yang, Zhou Rong-Hui, Pan Yu-Ping, Yao Hong-Chang, Li Zhong-Jun
Green Catalysis Center, College of Chemistry, Zhengzhou University, Zhengzhou 450001, China.
ACS Appl Mater Interfaces. 2020 Jul 29;12(30):34245-34253. doi: 10.1021/acsami.0c03369. Epub 2020 Jul 20.
Nitrogen dioxide (NO) detection is of great importance because the emission of NO gas profoundly endangers the natural environment and human health. However, a few challenges, including lowering detection limit, improving response/recovery kinetics, and reducing working temperature, should be further addressed before practical applications. Herein, a series of N-doped graphene quantum dot (N-GQD)-modified three-dimensional ordered macroporous (3DOM) InO composites are constructed and their NO response properties are studied. The results show that compared to pure 3DOM InO, reduced graphene oxide (rGO)/3DOM InO, and N-doped graphene sheets (NS)/3DOM InO, the N-GQDs/3DOM InO sensing materials exhibit higher NO responses with fast response and recovery speed and low working temperature (100 °C). In addition, the detection limit of NO response for the optimal N-GQDs/InO sensor is as low as 100 ppb. Upon exposure to CO, CH, NH, acetone, ethanol, toluene, and formaldehyde, only very weak responses could be observed, indicating good selectivity for the synthesized material. More attractively, the responses of the optimized N-GQDs/InO sensor exhibit no obviously big fluctuation over 60 days, implying good long-term stability. We suggest that the formation of heterojunctions between 3DOM InO and N-GQDs and the doping N atoms in N-GQDs play crucial roles in improving the NO sensing properties.
二氧化氮（NO）检测至关重要，因为NO气体的排放严重危害自然环境和人类健康。然而，在实际应用之前，还需要进一步解决一些挑战，包括降低检测限、改善响应/恢复动力学以及降低工作温度。在此，构建了一系列氮掺杂石墨烯量子点（N-GQD）修饰的三维有序大孔（3DOM）InO复合材料，并研究了它们对NO的响应特性。结果表明，与纯3DOM InO、还原氧化石墨烯（rGO）/3DOM InO和氮掺杂石墨烯片（NS）/3DOM InO相比，N-GQDs/3DOM InO传感材料对NO表现出更高的响应，具有快速的响应和恢复速度以及较低的工作温度（100°C）。此外，最佳N-GQDs/InO传感器对NO响应的检测限低至100 ppb。在暴露于CO、CH、NH、丙酮、乙醇、甲苯和甲醛时，只能观察到非常微弱的响应，表明合成材料具有良好的选择性。更具吸引力的是，优化后的N-GQDs/InO传感器的响应在60天内没有明显的大幅波动，这意味着具有良好的长期稳定性。我们认为，3DOM InO与N-GQDs之间形成异质结以及N-GQDs中的N原子掺杂在改善NO传感性能方面起着关键作用。
