Synthesis of 1-D ZnO nanorods and polypyrrole/1-D ZnO nanocomposites for photocatalysis and gas sensor applications

Abstract

1-D ZnO nanorods and PPy/1-D ZnO nanocomposites were prepared by the surfactant-assisted precipitation and in situ polymerization method, respectively. The synthesized nanorods and nanocomposites were characterized by UV-Vis spectrophotometer, Fourier transform-infrared spectroscopy (FTIR), X-ray diffraction (XRD) and field emission scanning electron microscope (FE-SEM), which gave the evidence of 1-D ZnO nanorods, polymerization of pyrrole monomer and strong interaction between PPy and 1-D ZnO nanorods, respectively. Photocatalytic activity of 1-D ZnO nanorods was conducted by 3 3 level full-factorial design to evaluate the effect of three independent process variables viz., dye concentration (crystal violet), catalyst concentration (1-D ZnO nanorods) and the reaction time on the preferred response: photodegradation efficiency (%). The PPy/1-D ZnO nanocomposites were used for the sensing of NH 3 , LPG, CO 2 and H 2 S gases, respectively, at room temperature. It was observed that PPy/1-D ZnO nanocomposites with different 1-D ZnO nanorod weight ratios (15 and 25%) had better selectivity and sensitivity towards NH 3 at room temperature.

Synthesis of PMMA/ZnO nanoparticles composite used for resin teeth

“…16 Nanostructured materials with unique and fascinating properties motivate scientists tremendously to explore and understand their formation and growth processes and following the critical volume in several studies we tried to find the right percentage of ZnO NPs in a PMMA matrix which could advance the properties of this new composite, because increasing the percentage of added NPs could downgrade some of them. 17,18 According to the presented state-of-the-art study, the aim of this research was: (i) To synthesize a composite PMMA/ZnO NPs material, to test its mechanical properties, and evaluate the developed microstructures; (ii) To investigate the wear resistance of resin teeth in a chewing simulator with two combinations, before and after thermal artificial ageing. This investigation included not only the classical testing samples, but also the real model of the shapes of first upper molars (testing resin teeth) and showed possible practical applications in dentistry.…”

Graphene-enhanced metal oxide gas sensors at room temperature: a review

“…The electrons are released into the semiconductor to decrease the width of hole accumulation layer when exposed to reducing gases, which increases the resistance of the sensor. The sensing performances of MOS sensors are heavily affected by the working temperature, because the working temperature influences the kinetics, conductivity and electron mobility of MOS [ 30 – 31 ]. Since sufficient thermal energy is required to overcome the potential barrier and achieve the required electron mobility, the operating temperature of MOS sensors is above 200 °C in general.…”

Hierarchically interconnected ZnO nanowires for low-temperature-operated reducing gas sensors: experimental and DFT studies

“…The gas The working temperature governs the reaction kinetics, conductivity, and electronic movements, which explicitly control the sensing activity of ZnO nanostructures. 18,19 Even though the surface redox reaction is activated at high temperature and enhances the reaction kinetics for sensing activity, ZnO nanostructures have shown prominent gas sensing performance at relatively high temperatures in the range from 300 1C to 500 1C. 20 These high working temperatures induce secondary grain growth, causing instability, inaccuracy, high power consumption, and lack of durability in the sensing mechanism.…”