| Summary: | 碩士 === 國立中興大學 === 材料科學與工程學系所 === 107 === Graphene, a two-dimensional (2-D) material, was best known for its high strength, high transmittance, high electrical and thermal conductivity in recent years. For gas sensor applications, 2-D graphene has excellent gas sensing properties such as the resistance change significantly when exposed to the target gas. The gas sensing mechanism is mainly attributed to the high surface area and the high carrier mobility at room temperature. In this study, reduced graphene oxide (rGO) film was fabricated by reduction of graphene oxide on zinc oxide (ZnO) nanowire arrays grown by the hydrothermal method. The reduction state was analyzed by scanning electron microscope, electron spectroscopy chemical analyzer, and Raman spectrometer. The rGO films were used for the nitric monoxide sensing.
The results show that the rGO films were fabricated on top of ZnO nanowire arrays by photocatalystic reduction of graphene oxide. The coverage of rGO films was reach 96% by 130 mW/cm2 white light radication for 7 minutes at and increasing with radication time.
For the nitric monoxide gas sensing, the rGO films exhibited sensitivity of 79% for 1000 ppb nitric monoxide sensing using the applied voltage of 100 mV in nitrogen atmosphere. The sensitivity and detection limit were 21% and 10 ppb. The current of rGO films can be recovered by light irradiation. The rGO films in this study have better sensing properties comparing with other researches because the rGO films supported by the ZnO nanowire arrays. Nitric monoxide gas can pass through the space below the rGO films and adsorbed on the backside of rGO films to cause the total area of gas adsorption increasing.
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