Facile synthesis of MgGa2O4/graphene composites for room temperature acetic acid gas sensing

• Published in: Sensors and actuators. B, Chemical Chemical, 2020-03, Vol.306, p.127453, Article 127453
• Main Authors: He, Lifang, Gao, Cuiping, Yang, Lei, Zhang, Kui, Chu, Xiangfeng, Liang, Shiming, Zeng, Dawen
• Format: Article
• Language: English
• Subjects: Acetic acid; Acids; Composite materials; Detection; Electrical resistivity; Gas sensing; Gas sensors; Graphene; Heterojunctions; MgGa2O4; Nanoparticles; Recovery time; Room temperature; Room temperature sensor; Sensors
• ISSN: 0925-4005; 1873-3077
• DOI: 10.1016/j.snb.2019.127453

•MgGa2O4/graphene composites was synthesized for room temperature acetic acid sensing.•The composites showed much higher sensing performance to acetic acid.•The response value of composite sensor to 100 ppm acetic acid reached 363.•The response and recovery time were about 50 s and 35 s, respectively.•The detection limit was as low as 1 ppb. 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 °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.