▎ 摘　　要

Hierarchical urchin-like hollow spheres of ZnO nanorods with reduced graphene oxide (Urc-ZGO) have been synthesized via an efficient one step solvothermal method. The ZnO hollow spheres with a size of 0.5-2 mu m are anchored homogeneously on the surface of reduced graphene oxide (RGO) layers. When used as a gas sensor for detection of NO2, the Urc-ZGO composite shows much higher sensitivity towards NO2 at room temperature (RT) than the corresponding RGO. It is found that Urc-ZGO hollow spheres prepared with 30 mg weight addition ratio of graphene (Urc-ZGO-30) exhibit the highest response at RT. The obvious enhancement of the gas sensing properties is attributed to the hierarchical hollow spheres in the structure of Urc-ZGO. (C) 2015 Elsevier Ltd and Techna Group S.r.l. All rights reserved.