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 degrees 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.