▎ 摘　　要

The development of sensing materials with superior performance is important for gas detection. Herein, MgGa2O4/graphene composites (MGO/G) with tunable graphene contents were synthesized using a facile hydrothermal method. Various characterization results showed that MgGa2O4 nanoparticles were evenly grown on graphene sheets and formed uniform composites, which were then applied as gas sensing materials. The gas sensing test results demonstrated that the MGO/G composite comprising of 0.1 wt% of graphene (MGO/G0.1 wt %) showed much higher sensing performance to acetic acid than other composites. In particular, at room temperature (RT) of 25 degrees C, the response value of MGO/G0.1 wt% composite sensor against 100 ppm of acetic acid reached 363, with the response and recovery time of 50 s and 35 s, respectively. Meanwhile, MGO/G0.1 wt % composite sensor exhibited ultra-low detection limit, as evidenced by a response value of 1.3 against 1 ppb of acetic acid. The superior sensing performance of MGO/G0.1 wt% composite was attributed to the heterojunctions formed between graphene and MgGa2O4 nanoparticles, as well as the high electrical conductivity of graphene. Collectively, MGO/G0.1 wt% composite sensor represents a promising candidate for RT acetic acid detection.