Thai Journal of Nanoscience and Nanotechnology

The effect of W dopants on the physical and optical properties and photocatalytic activity of ZnO synthesized by the co-precipitation method

2025-06-17T22:16:56+07:00

Due to the wastewater crisis, tungsten (W)-doped ZnO particles were synthesized with varying W dopant concentrations using the co-precipitation method for the enhancement of photocatalysis application, which can reduce the wastewater crisis by the degradation of pollutant molecules occurring by its process. The crystalline and optical properties of the synthesized powders were analyzed by various methods as well as photocatalytic performance. Among all conditions, the WZ-5 sample exhibited the lowest band gap energy at 3.11 eV and the highest photocatalytic efficiency, achieving 98.16% degradation within 60 minutes. These results demonstrate that tungsten doping can effectively enhance ZnO photocatalytic activity by promoting better charge carrier separation and extending light absorption, especially in the visible region, making W-doped ZnO a promising material for wastewater treatment applications.

Enhanced Piezo-Photocatalytic Degradation of Rhodamine B Using Different ZnO Nanostructures Under Xenon Irradiation and Ultrasonic Activation

2025-06-25T15:46:58+07:00

The contamination of wastewater with synthetic organic dyes has become a significant environmental challenge. To address this issue, zinc oxide (ZnO) has attracted considerable attention due to its non-toxic nature and versatile applications, especially in photocatalytic materials. Enhancing the efficiency of photocatalysis requires reducing electron-hole recombination, which can be achieved through doping or composite formation with other materials. Additionally, the integration of piezoelectric properties presents an effective strategy to enhance ZnO-based photocatalysts, given their excellent piezoelectric characteristics. In this study, the piezo-photocatalysis properties of ZnO nanostructures with spherical, plate-like, and rod-like morphologies were systematically investigated under xenon lamp irradiation coupled with piezo-mechanical stimulation. Rhodamine B (RhB) was employed as a model dye to evaluate photocatalytic performance under various conditions, for example, light irradiation, piezo-assisted activation combined with light irradiation, and the absence of light. The absorbance of the dyes under photocatalytic reaction was then measured using a UV-visible spectrophotometer. The experimental results revealed that the highest dye degradation efficiency was achieved when using rod-like ZnO photocatalyst under combined piezo-assisted and light irradiation. This superior performance can be attributed to its asymmetric geometry, which enhances the generation of an internal electric field on the photocatalyst surface under piezoelectric activation, thereby promoting efficient charge separation. Moreover, the 1D structure of the rod-like facilitates directed electron transport along its longitudinal axis and provides a higher density of active sites, contributing further to their enhanced photocatalytic activity.

Tuning Electrical and Optical Properties of SnO2 Films: Influence of Sb Dopant Concentration and Coating Layer in Spin-Coating Process

2025-05-28T21:04:41+07:00

This study investigates the optical and electrical properties of antimony (Sb)-doped tin oxide (SnO₂), commonly referred to as ATO, transparent conducting thin films synthesized via a wet chemical route. The films were fabricated using a sol-gel method combined with spin-coating. The effects of Sb doping concentrations (1, 3, and 5 mol%) and the number of coating layers (5 and 10) on the films' properties were systematically examined. ATO films were deposited onto glass substrates at a constant spin speed of 2000 rpm, followed by calcination at 600 °C for 2 hours. X-ray diffraction (XRD) analysis confirmed the formation of a tetragonal SnO₂structure with no secondary phases. Optical measurements revealed high transparency in the visible range, with transmittance values between 60% and 80%. The lowest resistivity of 0.16 Ω·m was achieved with 5 mol% Sb and 10 coating layers, which also corresponded to the highest carrier concentration of 2 × 10⁹ cm^-3, as determined by Hall effect measurements. These results demonstrate that optimized ATO films possess desirable properties for electronic and optoelectronic device applications.

Effect of Al dopant on Physical and Optical Properties of Er-doped CuS prepared by co-precipitation process

2025-06-26T18:19:14+07:00

Considering the pressing demand for energy conservation, sustainable solutions in the building sector have become paramount. This study focuses on the development of sustainable, energy-efficient technologies for window glasses and transparent solar shielding film materials. The primary objective is to achieve a delicate balance: enabling the transmission of visible light while effectively shielding against Near Infrared Radiation (NIR). Copper sulfide (CuS) emerges as a promising p-type semiconductor material due to its favorable NIR shielding performance. In this research, CuS particles were synthesized via a simple co-precipitation method. Additionally, with the certain dopant ratios of erbium (Er) as rare earth dopants and the various dopant ratios of aluminum (Al), explore the enhancement of the solar spectral selectivity. The X-ray diffraction technique was used to characterize the crystalline structure of the synthesized powders, while X-ray photoelectron spectroscopy was utilized to explore the valence states of the samples. Furthermore, the optical properties of the synthesized powders and prepared thin films were observed using a diffuse reflectance spectrophotometer. Lastly, the thermal insulation performance of the prepared thin films was evaluated using a custom device, supplemented by an infrared lamp. The NIR shielding performance was assessed by examining the lowest transmittance in the NIR region, attributed to changes in the valence state induced by the dopant, thereby enhancing the semiconducting behavior of CuS.

Green Light Emission from Tb3+ ion doped Boro-Tellurite Glass Potential for Scintillation and Thermoluminescence Material Application

2025-06-17T22:20:23+07:00

Rare-earth doped glasses have gained significant attention due to their potential applications in photonic devices, including scintillators and thermoluminescence dosimeters (TLD). Among these, terbium (Tb³⁺) ion is known for their strong green luminescence, making them valuable for optical and radiation detection technologies. The combination of TeO₂ and other glass modifiers enhances the optical and structural properties of the host matrix, making it suitable for doping with rare-earth ions. The primary goal of this study is to synthesize and characterize a series of Tb³⁺ doped tellurite-based glasses with varying concentrations of terbium oxide (Tb₂O₃) for scintillation and thermoluminescence material application. Glasses with the molar composition (30-x) TeO₂: 20B₂O₃: 20MgO: 10Li₂O: 10Al₂O₃: 10La₂O₃: xTb₂O₃ (x is 0.0, 1.0, 2.0, 3.0, 4.0 and 5.0 mol%) were produced using a conventional melt-quenching approach. X-ray diffraction analysis confirmed that the glass was amorphous. In addition, the UV-VIS-NIR spectrometer recorded the absorption spectra of a number of peak values. As the concentrations of Tb³⁺ increase, both the radioluminescence (RL) and photoluminescence (PL) results increase. The glass samples exhibited strong luminescence spectra with prominent emission bands at 545 nm, corresponding to the characteristic transitions of Tb³⁺ ion. The highest luminescence efficiency of Tb³⁺ ion was observed at a concentration of 4 mol%. In the prepared glasses, the RL and PL obtained from different concentrations of Tb³⁺ ion is almost close to the green light region, as shown in the CIE 1931 chromaticity diagram. Furthermore, the thermoluminescence (TL) parameters were calculated using Chen is peak shape method, such as activation energy (E) and frequency factor (S). The developed glasses show promise for use in Scintillation and TLD.