Enhancement of H2S sensing performance of p-CuO nanofibers by loading p-reduced graphene oxide nanosheets

Abstract

Being compared to p-n heterojunctions, less attention has been paid to p-p heterojunctions for gas sensing studies. Motivated by this fact, herein, gas sensing characteristics of p-reduced graphene oxide (RGO) loaded p-CuO nanofibers (NFs) will be presented. In order to find the optimal value of RGO loading, different amounts of RGO (0.05–1.5 wt%) were added to the electrospun CuO NFs. The results of sensing tests showed that the CuO-0.5 wt% RGO has the best sensitivity to H2S at 300 °C. Also, low response to the interfering gases demonstrated the good selectivity of the optimal sensor towards H2S. Underlying sensing mechanism is discussed in details. High response of CuO-0.5 wt% RGO sensor towards H2S was related to NF morphology, presence of RGO, high intrinsic sensitivity of CuO towards H2S gas, presence of a lot of CuO nanograins along with the existence of the plenty of p-p heterojunctions, which will be changed by transformation of CuO to CuS. The results of present study can be used for design and fabrication of novel RGO containing p-p heterojunction gas sensors.