ZnTe Semiconductor-Polymer Gel Composited Electrolyte for Conversion of Solar Energy

Nanostructured cubic p-type ZnTe for dye sensitized solar cells (DSSCs) was synthesized from 1 : 1 molar ratio of Zn : Te by 600 W and 900 W microwave plasma for 30 min. In this research, their green emissions were detected at the same wavelengths of 563 nm, the energy gap (Eg) at 2.24 eV, and three Raman shifts at 205, 410, and 620 cm−1. The nanocomposited electrolyte of quasisolid state ZnO-DSSCs was in correlation with the increase in the JSC, VOC, fill factor (ff), and efficiency (η) by increasing the wt% of ZnTe-GPE (gel polymer electrolyte) to an optimum value and decreased afterwards. The optimal ZnO-DSSC performance was achieved for 0.20 wt% ZnTe-GPE with the highest photoelectronic energy conversion efficiency at 174.7% with respect to that of the GPE without doping of p-type ZnTe

Synthesis of h- and α

Hexagonal molybdenum oxide (h-MoO3) nano- and microrods were successfully synthesized by refluxing of (NH4)6Mo7O24·4H2O solutions with the pH 1 at 90°C for 1, 3, 5, and 7 h and were further transformed into orthorhombic molybdenum oxide (α-MoO3) microplates by calcination at 450°C for 6 h. These selected products were used to determine the degradation of methylene blue dye under 35 W xenon lamp for 0–180 min, due to the photocatalysis and photosensitization processes. In this research, catalytic activity of the metastable h-MoO3 has higher efficiency than that of the thermodynamically stable α-MoO3. Their phase and morphology transformation was also explained according to the experimental results

Ultrasonic-Assisted Synthesis, Characterization, and Optical Properties of Sb Doped ZnO and Their Photocatalytic Activities

Sb doped ZnO nanostructures were synthesized by an ultrasonic-assisted method. Effect of Sb dopant on the structure, morphology, and composition of as-synthesized Sb doped ZnO nanostructures was investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray (EDX) spectroscopy, and transmission electron microscopy (TEM). All samples were identified to wurtzite hexagonal ZnO structure. UV-visible spectra of the as-synthesized 3% Sb doped ZnO sample exhibit broad absorption bands at around 343 nm which is blue shift of 373 nm of pure ZnO. The photocatalytic activity was tested by decolorization of methylene blue (MB) solution under UV light. After 300 min irradiation, the degradation efficiencies were 56, 90, and 95% for ZnO, 1% Sb doped ZnO, and 3% Sb doped ZnO, respectively. The 3% Sb doped ZnO shows the highest photocatalytic activity than any other samples

Photocatalysis of WO 3

The degradation of methylene blue (MB) dye by tungsten oxide (WO3) photocatalyst synthesized by the 200°C conventional-hydrothermal (C-H) and 270 W microwave-hydrothermal (M-H) methods and commercial WO3 was studied under UV light irradiation for 360 min. The photocatalysts were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier transform infrared (FTIR) spectroscopy, Raman spectrophotometry, and UV visible spectroscopy to determine phase, morphology, vibration mode, and optical property. The BET analysis revealed the specific surface area of 29.74, 37.25, and 33.56 m2/g for the C-H WO3 nanoplates, M-H WO3 nanoplates, and commercial WO3 nanorods, respectively. In this research, the M-H WO3 nanoplates have the highest photocatalytic efficiency of 90.07% within 360 min, comparing to the C-H WO3 nanoplates and even commercial WO3 nanorods

Influence of PVP on the Morphologies of Bi 2

Different morphologies of Bi2S3 nanostructures were synthesized by a 180°C and 12 h solvothermal reaction of solutions containing Bi(NO3)3·5H2O and thioacetamide (CH3CSNH2) in diethylene glycol (DEG) as a solvent. The as-synthesized Bi2S3 products characterized by XRD, Raman spectroscopy, SEM, and TEM showed that they were well-crystallized orthorhombic Bi2S3 phase with morphologies of nanorod-like, sheaf-like, carnation-like, and microspherical, controlled by different contents of polyvinylpyrrolidone (PVP) in the solutions. Based on the experimental results, a growth mechanism was also proposed and discussed

HYDROTHERMAL-ASSISTED SYNTHESIS AND PHOTOLUMINESCENCE OF ZnO MICRORODS

Zinc oxide microrods were grown on Zn foils by a simple hydrothermal method. The XRD and SEM experimental results revealed the dense microrod-like wurtzite ZnO structure grown on Zn foils. The photoluminescence (PL) spectra at room temperature were measured. ZnO microrods exhibit photoluminescence broad emission at 500-650 nm using an excitation wavelength of 215 nm. By Gaussian analysis, the emission shows a maximum intensity at about 540 nm and a shoulder peak at around 570 nm which correspond to interstitial oxygen [O i -

Decolorization of Methylene Blue by Ag/SrSnO 3

SrSn(OH)6 precursors synthesized by a cyclic microwave radiation (CMR) process were calcined at 900°C for 3 h to form rod-like SrSnO3. Further, the rod-like SrSnO3 and AgNO3 in ethylene glycol (EG) were ultrasonically vibrated to form rod-like Ag/SrSnO3 composites, characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), electron microscopy (EM), Fourier transform infrared (FTIR) spectroscopy, and UV-visible analysis. The photocatalyses of rod-like SrSnO3, 1 wt%, 5 wt%, and 10 wt% Ag/SrSnO3 composites were studied for degradation of methylene blue (MB, C16H18N3SCl) dye under ultraviolet (UV) radiation. In this research, the 5 wt% Ag/SrSnO3 composites showed the highest activity, enhanced by the electron-hole separation process. The photoactivity became lower by the excessive Ag nanoparticles due to the negative effect caused by reduction in the absorption of UV radiation

Synthesis of Coral-Like, Straw-Tied-Like, and Flower-Like Antimony Sulfides by a Facile Wet-Chemical Method

Antimony sulfide (Sb2S3) was successfully synthesized from antimony chloride (SbCl3) and sodium thiosulfate pentahydrate (Na2S2O3·5H2O) in ethylene glycol (EG) without using any template by a facile wet-chemical method. X-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM) show that the products were orthorhombic Sb2S3 nanorods forming the coral-like, straw-tied-like, and flower-like architectures with the nanorods growing along the [001] direction. The energy gap (Eg) was determined by UV-visible absorption to be 1.52 eV

Hydrothermal Synthesis and Characterization of Bi 2

The pH effect of the precursor solutions on the phase, morphologies, and photocatalytic activity of Bi2MoO6 synthesized by a hydrothermal reaction at 180°C for 20 h was investigated. X-ray powder diffraction (XRD), Raman spectroscopy, Fourier transform infrared (FTIR) spectrometry, scanning electron microscopy (SEM), and transmission electron microscopy (TEM) revealed the presence of pure orthorhombic well-crystallized γ-Bi2MoO6 nanoplates, including the symmetric (A1g) and asymmetric (A2u) stretching vibrations of the MoO6 octahedrons involving the motion of apical oxygen atoms. The photocatalytic activity of Bi2MoO6 nanoplates at the pH 6 determined via the decomposition of rhodamine-B (RhB) organic dye was the highest at 98.66% decolorization under Xe light irradiation

Development of a rapid method for assessing the efficacy of antibacterial photocatalytic coatings

Visible-light activated photocatalytic coatings may represent an attractive antimicrobial solution in domains such as food, beverage, pharmaceutical, biomedical and wastewater remediation. However, testing methods to determine the antibacterial effects of photocatalytic coatings are limited and require specialist expertise. This paper describes the development of a method that enables rapid screening of coatings for photocatalytic-antibacterial activity. Relying on the ability of viable microorganisms to reduce the dye resazurin from a blue to a pink colour, the method relates the time taken to detect this colour change with number of viable microorganisms. The antibacterial activity of two photocatalytic materials (bismuth oxide and titanium dioxide) were screened against two pathogenic organisms (Escherichia coli and Klebsiella pneumoniae) that represent potential target microorganisms using traditional testing and enumeration techniques (BS ISO 27447:2009) and the novel rapid method. Bismuth oxide showed excellent antibacterial activity under ambient visible light against E. coli, but was less effective against K. pneumoniae. The rapid method showed excellent agreement with existing tests in terms of number of viable cells recovered. Due to advantages such as low cost, high throughput, and less reliance on microbiological expertise, this method is recommended for researchers seeking an inexpensive first-stage screen for putative photocatalytic-antibacterial coatings