SYNTHESIS AND CHARACTERIZATION OF METAL OXIDE-GRAPHENE NANOCOMPOSITE BY SOLVOTHERMAL METHOD FOR CARBON MONOXIDE DETECTION

• Main Author: Estananto
• Format: Dissertations
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/80090
• Institution: Institut Teknologi Bandung

Carbon Monoxide (CO) is one of the air pollutant gases that is harmful to the health of living things. For this reason, a device is needed to detect the presence dan concentration of the gas. One commonly used detection method is using a gas reaction on the surface of a metal oxide solid. In this research, material engineering of tungsten trioxide (WO3) was carried out by increasing the sensitivity of the materials to Carbon Monoxide gas. The engineering was done by synthesizing WO3, and Graphene using the solvothermal method. The novelty of this research is the synthesis of WO3-Graphene with solvothermal methods using the capping agent 2-Methoxyethanol to stabilize nanoparticles, prevent excessive agglomeration, and control the shape and size of the nanoparticle. WO3-Graphene nanocomposite synthesis at a 2:1 ratio using a 2-Propanol solvent produces a 64 nm-sized nanowire-crystallite-structured nano-composite cluster. The exposure of this material in 10 ppm of CO gas at 300oC gives a maximum response of 21.5. The presence of Graphene improves sensor performance through increased electron transfer from the CO gas at the active site of the WO3 surface, which shortened response time and increased selectivity to CO gas. The synthesis of WO3 without Graphene in 2-Propanol and 2-Methoxyethanol 20:20 solvents produces an average 88 nm crystallite-sized WO3 fragment. The use of 2-methoxyethanol as a capping agent increases the spread of the WO3. Exposure to 60 ppm CO gas at 300oC gives a 13.5 response. This material works better at a temperature of 200oC which gives a response of 49 and shortens the response time. The spread of small particles of WO3 provides a large surface of reaction. The decrease in CO gas concentration to 20 ppm at 200oC only produces a sensor response of 1.32. The synthesis of WO3-Graphene composites was accomplished with the help of a capping agent. The WO3-Graphene composite nanoparticles generated by the solvothermal synthesis of WCl6 and 5 mg Graphene in 20:20 solvent was 50 nm in size. With a response value of 8.54, the resulting WO3-Graphene composite can detect and be selective against 10 ppm CO at a temperature of 200oC. Engineering the WO3-Graphene synthesis process using a capping agent solvent opens up a vehicle for engineering to design the structure, particle size, and morphology.