Ni Luh Wulan Septiani

SnO2 Nanostructure as Pollutant Gas Sensors: Synthesis, Sensing Performances, and Mechanism

A significant amount of pollutants is produced from factories and motor vehicles in the form of gas. Their negative impact on the environment is well known; therefore detection with effective gas sensors is important as part of pollution prevention efforts. Gas sensors use a metal oxide semiconductor, specifically SnO2 nanostructures. This semiconductor is interesting and worthy of further investigation because of its many uses, for example, as lithium battery electrode, energy storage, catalyst, and transistor, and has potential as a gas sensor. In addition, there has to be a discussion of the use of SnO2 as a pollutant gas sensor especially for waste products such as CO, CO2, SO2, and NOx. In this paper, the development of the fabrication of SnO2 nanostructures synthesis will be described as it relates to the performances as pollutant gas sensors. In addition, the functionalization of SnO2 as a gas sensor is extensively discussed with respect to the theory of gas adsorption, the surface features of SnO2, the band gap theory, and electron transfer.

Preparation of Graphene–Zinc Oxide Nanostructure Composite for Carbon Monoxide Gas Sensing

A simple method to synthesize graphene–zinc oxide nanocomposite has been developed. A reduced graphene oxide–ZnO nanocomposite was prepared using a reflux method with ethylene glycol as medium. X-ray diffraction analysis, scanning electron microscopy, energy-dispersive spectrometry, and nitrogen adsorption–desorption measurements were used to characterize the resulting composite materials. The highest response of about 98% was observed when using pure ZnO at 300°C, while the second highest sensor response of about 96% was achieved by graphene–ZnO with 1:3 composition. It was found that the graphene–zinc oxide hybrid has potential to improve sensor performance at low temperature. The graphene–ZnO hybrid with 1:3 composition showed good response of 36% at 125°C, an operating temperature at which pure ZnO showed no response.

High Performance Carbon Monoxide Sensor Based on Nano Composite of SnO 2 -Graphene

SnO₂-graphene nanocomposite thick films have been successfully synthesized using polyol method. Reflux with ethylene glycol as medium was employed to produce the nanocomposite. Crystal structure characterization using X-Ray diffraction shows the nanocomposites have good crystalinity without any impurity. Scanning electron microscopy and transmission electron microscopy characterization results show SnO₂ has spherical shape and well distributed on the graphene layer. The size of SnO₂ particles is around 5–8 nm. To confirm the improvement effect of grapheme addition to SnO₂, sensor testing was conducted toward 30 ppm carbon monoxide (CO) gas at 150 °C compared with pure SnO₂ and pure graphene. The sensor responses are 88.11%, 52.84%, and 0.93%, respectively.

Synthesis of Zinc Oxide Nanoparticles using Anthocyanin as a Capping Agent

Zinc Oxide nanoparticles have been successfully synthesized by utilizing anthocyanin as a capping agent by thermal decomposition of precursor route. The influence of the high and low concentrations of the anthocyanin to the shape and size of ZnO was investigated in this work. The anthocyanin was obtained from Indonesia black rice extract with methanol as a solvent. The crystallinity and morphology properties were characterized by X-Ray Diffractometer (XRD), and Scanning Electron Microscope (SEM), respectively. XRD result showed that ZnO was formed with good crystallinity without any second phase and had a hexagonal wurtzite crystal structure. SEM result revealed that ZnO with a low concentration of anthocyanin has a spherical shape with a uniform size of about 16 nm while ZnO with a high concentration of anthocyanin has a rod-like shape. The size of spherical ZnO in this work is smaller than ZnO from the same method of synthesis without anthocyanin (~30 nm).

Preparation of SnO2 Thin Film Nanostructure for CO Gas Sensor Using Ultrasonic Spray Pyrolysis and Chemical Bath Deposition Technique

Preparation of SnO2 Thin Film Nanostructure for CO Gas Sensor Using Ultrasonic Spray Pyrolysis and Chemical Bath Deposition Technique B. Yuliartoa,b,∗, G. Gumilar, D.W. Zulhendri, Nugraha and N.L.W. Septiani Advanced Functional Materials Laboratory, Engineering Physics Department, Institut Teknologi Bandung, Bandung, Indonesia Research Center for Nanosciences and Nanotechnology, Institut Teknologi Bandung, Bandung, Indonesia