Abstract
Constructing heterostructure and N-doping are two effective methods to improve gas sensing performance. Herein, a facile novel solution calcination strategy has been proposed to synthesize N-doped carbon sheets-zinc oxide (NC-ZnO) hybrids for low concentration NO2 detection. The formation of NC is accompanied by generation of ZnO particles on its surface to construct heterostructure. Intriguingly, NO3- acts as an expanding agent and N source in the calcination process, wherein the N elements are directly doped into carbon sheets. As expected, the prepared heterostructural NC-ZnO-63 hybrids exhibit 74.9 times enhancement of response as well as high sensitivity (~ 265.8–20 ppm NO2), excellent repeatability and selectivity compared with pure ZnO. Importantly, the measured detection limit of the NC-ZnO-63 sensor to NO2 is about 100 ppb (~ 0.3) and the calculated detection limit is 2.65 ppb. Furthermore, the influences of humidity on testing NO2 gas have been researched systematically which would provide guidance for practical use of similar sensors. In this work, ZnO and derived carbon are low-cost, eco-friendly, and the synthesis strategy presented here is simple and repeatable, which provides new idea for mass fabricating other-type metal oxides-NC hybrids for various applications.
NSTL
Elsevier