Optical Sensor Fabricated From Graphene Oxide/Ga2O3 Composite

Graphene oxide (GO) is a promising material for several applications. The studies of GO optical sensors have been conducted in numerous reports in recent years. Especially, producing GO from disposed zinc batteries has attracted much attention because it facilitates human to protect the environment. This study arms to produce GO/Ga2O3 composite to make optical sensors. The GO nanosheets were exfoliated from disposed graphite rods of waste batteries. Ga2O3 was then deposited on GO via hydrothermal method. The GO/Ga2O3 film was deposited on filter paper using vacuum filtration method for fabricating the optical device. A field emission scanning electron microscope (FESEM) image indicates that GO nanosheets exfoliated by electrochemical method are multi-layers. FESEM image also reveals that Ga2O3 was successfully deposited on GO. The optical sensor exposed the strong repeatability and reliability. The photocurrent of 9 µA measured at 10 V under the excitation of 650 nm light was obtained. The rise time and fall time of sensor are determined at 3.7 s and 4.2 s, respectively. The results indicate that waste zinc batteries can be used to produce valuable products.