Au-Decorated Polyaniline-ZnO Electrospun Composite Nanofiber Gas Sensors with Enhanced Response to NO2 Gas

Abstract

Ternary systems are less studied for sensing applications due to complex synthesis procedures. However, they have more sources of resistance modulation, leading to an enhanced gas response. In this study, a ternary system, namely Au-decorated ZnO-polyaniline (PANI) composite nanofibers with different amounts of PANI (10, 25, and 50 wt.%) were synthesized for NO2 gas sensing studies. First, ZnO nanofibers were synthesized by electrospinning, and then an Au layer (9 nm) was coated on the ZnO nanofibers. Finally, PANI was coated onto the prepared Au-decorated ZnO nanofibers. NO2 gas sensing investigations indicated that the sensor with 25 wt.% PANI had the best response to NO2 gas at 300 °C. In addition, the optimized sensor exhibited high selectivity to NO2 gas. The improved performance of the optimal gas sensor was attributed to the role of Au, the formation of ZnO-PANI heterojunctions, and the optimal amount of PANI. The promising effect of this ternary system for NO2 sensing was demonstrated, and it can be extended to other similar systems.

Biosynthesis of Gold- and Silver-Incorporated Carbon-Based Zinc Oxide Nanocomposites for the Photodegradation of Textile Dyes and Various Pharmaceuticals

“…These results align with those reported by Ramesan et al [70], who observed a weight loss of 74.2% at 700 • C for Ag-doped ZnO-C material. The TGA curve of Au-decorated ZnO-PANI prepared by Bonyani et al [72] showed a 25% weight loss from 0 to 700 • C, which is comparable to the findings in this study.…”

Recent progress in polyaniline-based chemiresistive flexible gas sensors: design, nanostructures, and composite materials

“…As a gas sensing material, PANI/ZnO nanohybrids have also been conrmed to exhibit the advantages of lower detection limits, faster response times, and more stable sensing signals. [139][140][141][142] As shown in Fig. 10j-l, Wang et al 143 loaded PANI/ ZnO nanohybrids on a self-formed natural grapefruit peel aerogel (GPA) to weaken the agglomeration tendency.…”

Overall perspective of electrospun semiconductor metal oxides as high-performance gas sensor materials for NOx detection

“…In addition, for the sample with 50 wt% PANI, many ZnO nanofibers are bonded together, which ultimately decreases the overall surface area of the ZnO nanofibers. 95 Au-decorated ZnO-NI (25 wt%) composite nanofiber gas sensor showed a response ( R g / R a ) of 50 towards 50 ppm NO 2 at 300 °C. The enhanced sensing response stemmed from the optimal amount of Au, generation of Au–ZnO Schottky junctions, and catalytic effect of Au NPs.…”