Photocatalytic Degradation of Phenol Using Nb-Loaded ZnO Nanoparticles

Niobium-doped Zinc Oxide nanoparticles (Nb-doped ZnO NPs) in the range of 20 and 40 nm were synthesized by Flame Spray Pyrolysis (FSP) technique. The crystalline phase, morphology and size of the nanoparticles were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM) and UV-vis spectroscopy. The specific surface area of the nanoparticles was measured by nitrogen adsorption (BET analysis). The pure ZnO and Nb-doped ZnO NPs were found to have the clear spherical, hexagonal and rod-like morphologies. To the best of our knowledge, the application of Nb-doped ZnO NPs as a photocatalyst has not been reported yet. In this study, the photocatalytic activities of pure ZnO and Nb-doped ZnO NPs were determined by studying the mineralization of phenol under UV light illumination. The results indicated that all Nb-doped ZnO NPs have better photocatalytic activity than the pure ZnO nanoparticles. It was found that, 0.50 mol% Nb-doped ZnO NPs exhibited the fastest response to the degradation of phenol

Effects of Niobium-Loading on Sulfur Dioxide Gas-Sensing Characteristics of Hydrothermally Prepared Tungsten Oxide Thick Film

Nb-loaded hexagonal WO3 nanorods with 0–1.0 wt% loading levels were successfully synthesized by a simple hydrothermal and impregnation process and characterized for SO2 sensing. Nb-loaded WO3 sensing films were produced by spin coating on alumina substrate with interdigitated gold electrodes and annealed at 450°C for 3 h in air. Structural characterization by X-ray diffraction, high-resolution transmission electron microscopy, and Brunauer-Emmett-Teller analysis showed that spherical, oval, and rod-like Nb nanoparticles with 5–15 nm mean diameter were uniformly dispersed on hexagonal WO3 nanorods with 50–250 nm diameter and 100 nm–5 µm length. It was found that the optimal Nb loading level of 0.5 wt% provides substantial enhancement of SO2 response but the response became deteriorated at lower and higher loading levels. The 0.50 wt% Nb-loaded WO3 nanorod sensing film exhibits the best SO2 sensing performances with a high sensor response of ~10 and a short response time of ~6 seconds to 500 ppm of SO2 at a relatively low optimal operating temperature of 250°C. Therefore, Nb loading is an effective mean to improve the SO2 gas-sensing performances of hydrothermally prepared WO3 nanorods

High Photoelectric Conversion Efficiency of Metal Phthalocyanine/Fullerene Heterojunction Photovoltaic Device

This paper introduces the fundamental physical characteristics of organic photovoltaic (OPV) devices. Photoelectric conversion efficiency is crucial to the evaluation of quality in OPV devices, and enhancing efficiency has been spurring on researchers to seek alternatives to this problem. In this paper, we focus on organic photovoltaic (OPV) devices and review several approaches to enhance the energy conversion efficiency of small molecular heterojunction OPV devices based on an optimal metal-phthalocyanine/fullerene (C60) planar heterojunction thin film structure. For the sake of discussion, these mechanisms have been divided into electrical and optical sections: (1) Electrical: Modification on electrodes or active regions to benefit carrier injection, charge transport and exciton dissociation; (2) Optical: Optional architectures or infilling to promote photon confinement and enhance absorption