scholarly journals Graphene Oxide-Doped MgO Nanostructures for Highly Efficient Dye Degradation and Bactericidal Action

2021 ◽  
Vol 16 (1) ◽  
Author(s):  
M. Ikram ◽  
T. Inayat ◽  
A. Haider ◽  
A. Ul-Hamid ◽  
J. Haider ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Dye Degradation ◽  
Inhibition Zone ◽  
Chemical Precipitation ◽  
Band Gap Energy ◽  
Cubic Phase ◽  
Electron Hole ◽  
Fixed Amount ◽  
E Coli ◽  
Spectroscopy Optical

AbstractVarious concentrations (0.01, 0.03 and 0.05 wt ratios) of graphene oxide (GO) nanosheets were doped into magnesium oxide (MgO) nanostructures using chemical precipitation technique. The objective was to study the effect of GO dopant concentrations on the catalytic and antibacterial behavior of fixed amount of MgO. XRD technique revealed cubic phase of MgO, while its crystalline nature was confirmed through SAED profiles. Functional groups presence and Mg-O (443 cm−1) in fingerprint region was evident with FTIR spectroscopy. Optical properties were recorded via UV–visible spectroscopy with redshift pointing to a decrease in band gap energy from 5.0 to 4.8 eV upon doping. Electron–hole recombination behavior was examined through photoluminescence (PL) spectroscopy. Raman spectra exhibited D band (1338 cm−1) and G band (1598 cm−1) evident to GO doping. Formation of nanostructure with cubic and hexagon morphology was confirmed with TEM, whereas interlayer average d-spacing of 0.23 nm was assessed using HR-TEM. Dopants existence and evaluation of elemental constitution Mg, O were corroborated using EDS technique. Catalytic activity against methyl blue ciprofloxacin (MBCF) was significantly reduced (45%) for higher GO dopant concentration (0.05), whereas bactericidal activity of MgO against E. coli was improved significantly (4.85 mm inhibition zone) upon doping with higher concentration (0.05) of GO, owing to the formation of nanorods.

scholarly journals Nitrogen and Carbon Nitride-Doped TiO2 for Multiple Catalysis and Its Antimicrobial Activity

2021 ◽  
Vol 16 (1) ◽  
Author(s):  
Atif Ashfaq ◽  
Muhammad Ikram ◽  
Ali Haider ◽  
Anwar Ul-Hamid ◽  
Iram Shahzadi ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Carbon Nitride ◽  
Dye Degradation ◽  
Morphological Properties ◽  
Degree Of Crystallinity ◽  
Bandgap Energy ◽  
Fixed Amount ◽  
E Coli ◽  
Vis Spectroscopy ◽  
Co Precipitation

AbstractNitrogen (N) and carbon nitride (C3N4)-doped TiO2 nanostructures were prepared using co-precipitation route. Fixed amount of N and various concentrations (0.1, 0.2, 0.3 wt%) of C3N4 were doped in TiO2 lattice. Through multiple techniques, structural, chemical, optical and morphological properties of samples were thoroughly investigated. XRD results verified anatase TiO2 presence along the substitutional doping of N, while higher degree of crystallinity as well as increased crystallite size were noticed after doping. HR-TEM study revealed formation of nanostructures incorporated on two dimensional (2D) C3N4 nanosheet surface. Elemental composition was checked out using EDS technique which confirmed the presence of dopant in product. Optical characteristics were evaluated with UV–vis spectroscopy which depicted representative redshift in absorption spectra resulted in a reduction in bandgap energy in N/C3N4-doped TiO2 samples. The formation of Ti–O–Ti bonds and different molecular vibrations were disclosed by FTIR. Trap sites and charge carrier’s migration in the materials were evaluated with PL spectroscopy. Multiple catalytic activities (photo, sono and photo-sono) were undertaken to evaluate the dye degradation performance of prepared specimen against methylene blue and ciprofloxacin. Further, antimicrobial activity was analyzed against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) bacteria.

scholarly journals Photocatalytic degradation of reactive black dye using ZnO – CeO2 Nanocomposites

2021 ◽  
Author(s):  
Saravanan M. ◽  
Vigneshwar S. ◽  
Gautham B. Jegadeesan ◽  
Ponnusami Venkatachalam
Keyword(s):  
Dye Degradation ◽  
Uv Light ◽  
Precursor Solution ◽  
Chemical Precipitation ◽  
Bandgap Energy ◽  
Cubic Phase ◽  
X Ray Diffraction ◽  
Oxidation Rates ◽  
Diffraction Patterns ◽  
Zno Powder

Abstract Nano-CeO2 was synthesized via the chemical precipitation of cerium precursor solution, and then mixed with nano-ZnO at various weight ratios to obtain ZnO-CeO2nanocomposites. The composites were characterized for their morphological and photocatalytic properties. X-ray diffraction patterns of the pristine metal oxides corresponded well with (1 0 1) and (1 1 1) peaks of hexagonal wurtzite like-ZnO and cubic-phase CeO2, respectively. The band gap of the ZnO-CeO2nanocomposite was 3.08 eV, while that of pristine CeO2 and ZnO powder was 3.24 eV and 3.12 eV respectively. Photocatalytic activity of ZnO-CeO2composite was evaluated at various Reactive Black (RB) dye and catalyst concentrations. A 1:1 wt ratio ZnO-CeO2 nanocompsite provided the maximum (~ 85%) RB oxidation under UV light within 90 minutes. Rate of dye degradation obtained with ZnO-CeO2nanocomposite was almost 1.5 times more than that obtained with bare ZnO. It was observed that increase in CeO2 to ZnO ratio increased oxidation rates up to 1:1 wt ratio. Increasing CeO2 ratio beyond 1:1 wt. ratio did not significantly increase RB oxidation. The results confirm that addition of CeO2 to ZnO has resulted in lowering its bandgap energy and in-turn favors oxidation of RB dye under UV light.

scholarly journals Innovative Ag–TiO2 Nanofibers with Excellent Photocatalytic and Antibacterial Actions

Catalysts ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 1234
Author(s):  
Petronela Pascariu ◽  
Corneliu Cojocaru ◽  
Anton Airinei ◽  
Niculae Olaru ◽  
Irina Rosca ◽  
...  
Keyword(s):  
Band Gap Energy ◽  
Morphological Characterization ◽  
Pure Tio2 ◽  
Electron Hole ◽  
Tio2 Nanofibers ◽  
One Dimensional ◽  
E Coli ◽  
Small Crystals ◽  
Tio2 Nanostructures ◽  
Hole Recombination

Ag–TiO2 nanostructures were prepared by electrospinning, followed by calcination at 400 °C, and their photocatalytic and antibacterial actions were studied. Morphological characterization revealed the presence of one-dimensional uniform Ag–TiO2 nanostructured nanofibers, with a diameter from 65 to 100 nm, depending on the Ag loading, composed of small crystals interconnected with each other. Structural characterization indicated that Ag was successfully integrated as small nanocrystals without affecting much of the TiO2 crystal lattice. Moreover, the presence of nano Ag was found to contribute to reducing the band gap energy, which enables the activation by the absorption of visible light, while, at the same time, it delays the electron–hole recombination. Tests of their photocatalytic activity in methylene blue, amaranth, Congo red and orange II degradation revealed an increase by more than 20% in color removal efficiency at an almost double rate for the case of 0.1% Ag–TiO2 nanofibers with respect to pure TiO2. Moreover, the minimum inhibitory concentration was found as low as 2.5 mg/mL for E. coli and 5 mg/mL against S. aureus for the 5% Ag–TiO2 nanofibers. In general, the Ag–TiO2 nanostructured nanofibers were found to exhibit excellent structure and physical properties and to be suitable for efficient photocatalytic and antibacterial uses. Therefore, these can be suitable for further integration in various important applications.

Structural and morphological characterization of CdS nanoparticles

2020 ◽  
Vol 10 ◽  
Author(s):  
Manish Dwivedi ◽  
Vijay Tripathi ◽  
Dhruv Kumar ◽  
Dwijendra K. Gupta
Keyword(s):  
Blue Shift ◽  
Chemical Precipitation ◽  
Morphological Characterization ◽  
Precipitation Method ◽  
Cds Nanoparticles ◽  
Cubic Phase ◽  
Simple Chemical ◽  
Xrd Patterns ◽  
Average Size ◽  
Physical Tools

Aims: CdS nanoparticles are an attractive material having application in various field like as pigment in paints, biotag for bioimaging and many more optoelectronic as well as biological applications. Present study aims to synthesize and characterize the CdS nanoparticles to make it applicable in different areas Objectives: Preparation CdS nanoparticles by using simple and facile chemical methods and further physical and structural characterization using various physical tools Methods: In present work CdS nanoparticles has been synthesized by using rationally simple chemical precipitation method with some modi-fication on temperature and incubation time in existed methods. Characterizations were done by employing XRD, SEM, TEM, AFM tech-niques Results: Simple chemical method produces the CdS nanoparticles with the size about 100-200 nm in length and 5-10 nm in diameter. The SEM studies show that the CdS nanoparticles can agglomerate and form a continuous network like structure. The X-ray diffraction (XRD) measurements show the single-phase formation of CdS nanoparticles with the structure of cubic phase, and the broadening of XRD patterns indicates that the prepared samples are nanostructured. Our analysis on CdS nanoparticles by using transmission electron microscope and atomic force microscope (AFM) revealed that the nanoparticles form both spherical and nearly rod shaped with the average size applicable for biotagging. UV-Vis spectroscopic analysis reveals blue shift in the absorption peak probably caused by quantum confinement Conclusion: The observed CdS nanoparticles were appeared yellow in color. The XRD pattern of the CdS nanoparticles showed that the materials were of nanometric sized regime with a predominantly cubic phase along with the rod and round morphology. The study and char-acterization of CdS nanoparticles will bring us a new approach to understand biological problem by tagging nanoparticles with biomolecules and further suggests that the CdS nanoparticles formulate it more suitable biocompatible nanomaterial for biotagging and bioimaging

scholarly journals Enhanced Visible-Light Photocatalytic Performance of SAPO-5-Based g-C3N4 Composite for Rhodamine B (RhB) Degradation

Materials ◽  
2019 ◽  
Vol 12 (23) ◽  
pp. 3948
Author(s):  
Lingfang Qiu ◽  
Zhiwei Zhou ◽  
Mengfan Ma ◽  
Ping Li ◽  
Jinyong Lu ◽  
...  
Keyword(s):  
Photocatalytic Activity ◽  
Visible Light ◽  
Redox Reactions ◽  
Photocatalytic Performance ◽  
Dye Degradation ◽  
Thermal Polymerization ◽  
Light Illumination ◽  
Electron Hole ◽  
Visible Light Illumination ◽  
Visible Light Photocatalytic

Novel visible-light responded aluminosilicophosphate-5 (SAPO-5)/g-C3N4 composite has been easily constructed by thermal polymerization for the mixture of SAPO-5, NH4Cl, and dicyandiamide. The photocatalytic activity of SAPO-5/g-C3N4 is evaluated by degrading RhB (30 mg/L) under visible light illumination (λ > 420 nm). The effects of SAPO-5 incorporation proportion and initial RhB concentration on the photocatalytic performance have been discussed in detail. The optimized SAPO-5/g-C3N4 composite shows promising degradation efficiency which is 40.6% higher than that of pure g-C3N4. The degradation rate improves from 0.007 min−1 to 0.022 min−1, which is a comparable photocatalytic performance compared with other g-C3N4-based heterojunctions for dye degradation. The migration of photo-induced electrons from g-C3N4 to the Al site of SAPO-5 should promote the photo-induced electron-hole pairs separation rate of g-C3N4 efficiently. Furthermore, the redox reactions for RhB degradation occur on the photo-induced holes in the g-C3N4 and Al sites in SAPO-5, respectively. This achievement not only improves the photocatalytic activity of g-C3N4 efficiently, but also broadens the application of SAPOs in the photocatalytic field.

scholarly journals ZnO-based mutable Ag2S/Ag2O multilayered architectures for organic dye degradation and inhibition of E. coli and B. subtilis

2020 ◽  
Vol 394 ◽  
pp. 112472 ◽  
Author(s):  
Summal Zoha ◽  
Muneeb Ahmad ◽  
Syed Jazib Abbas Zaidi ◽  
Muhammad Naeem Ashiq ◽  
Waheed Ahmad ◽  
...  
Keyword(s):  
Dye Degradation ◽  
Organic Dye ◽  
E Coli ◽  
Organic Dye Degradation

Preparation and disinfection properties of graphene oxide/trichloroisocyanuric acid disinfectant

2021 ◽  
Author(s):  
li li jiang ◽  
Su Xu ◽  
Haitao Yu ◽  
Qi Cui ◽  
Rui Cao
Keyword(s):  
Electron Microscopy ◽  
Graphene Oxide ◽  
Minimum Inhibitory Concentration ◽  
Inhibitory Concentration ◽  
Kinetic Curve ◽  
X Ray ◽  
Bacterial Inhibition ◽  
E Coli ◽  
Blending Method ◽  
Trichloroisocyanuric Acid

Abstract In this study, graphene oxide (GO) was first prepared by the modified Hummer method. Then, the GO/trichloroisocyanuric acid (TCCA) composite was prepared by loading TCCA into GO with the blending method. X-ray diffraction, scanning electron microscopy, transmission electron microscopy, X-ray photoelectron spectroscopy and atomic force microscopy were used to characterize the composite. The results showed that TCCA was successfully loaded on the surface of GO or intercalated among GO layers. Next, the antibacterial performance of the composite against Escherichia coli and Staphylococcus aureus was tested by the 96-well plate assay. A bactericidal kinetic curve, bacterial inhibition tests, and the mechanism of bacterial inhibition is discussed. The results showed that the minimum inhibitory concentration of the GO/TCCA composite (GO:TCCA ratio = 1:50) was 327.5 µg/mL against E. coli and 655 µg/mL against S. aureus. At the minimum inhibitory concentration, the inhibition rate of the GO/TCCA composite exceeded 99.46% against E. coli and 99.17% against S. aureus. The bactericidal kinetic curves indicate that the GO/TCCA composite has an excellent bactericidal effect against E. coli and S. aureus.

scholarly journals One-Pot Synthesis of Ru-Doped ZnO Oxides for Photodegradation of 4-Chlorophenol

2018 ◽  
Vol 2018 ◽  
pp. 1-12 ◽  
Author(s):  
Maria E. Manríquez ◽  
Luis Enrique Noreña ◽  
Jin An Wang ◽  
Lifang Chen ◽  
Jose Salmones ◽  
...  
Keyword(s):  
Band Gap ◽  
Mixed Oxides ◽  
Active Surface ◽  
Band Gap Energy ◽  
X Ray Diffraction ◽  
Electron Hole ◽  
One Pot ◽  
Notable Increase ◽  
Doped Zno ◽  
The One

The photocatalytic degradation of 4-chlorophenol in water using Ru-doped ZnO mixed oxides (0, 0.5, 1, and 3 wt% RuO2) synthesized by the one-pot homogeneous coprecipitation method is reported. ZnO with wurtzite structure was present in the mixed oxide as corroborated by Raman spectroscopy and X-ray diffraction analysis. All the samples showed nanorod morphological features. The presence of Ru6+/Ru4+ couples on ZnO modified the band gap of the mixed oxides and led to a shift of the band gap energy from 3.20 eV to 3.07 eV. Ru addition increased the surface area and significantly promoted the formation of active surface oxygen species such as hydroradicals evidenced by the fluorescence spectroscopy measurement. In the photodegradation of 4-chlorophenol solution under UV irradiation, a notable increase in photoactivity was obtained as the amount of RuO2 in the mixed oxides increased to 3 wt%. The charge transfer between Ru6+/Ru4+ couples and ZnO nanoparticles together with the formation of free radical oxidant species effectively inhibits electron-hole recombination rate, thus favoring the photodegradation of 4-chlorophenol.

scholarly journals Antibacterial activity of ginger extracts on bacteria isolated from digestive tract infection patients attended Muhoza Health Center

2020 ◽  
Vol 11 (2) ◽  
pp. 35-41
Author(s):  
Callixte Yadufashije ◽  
Adolyne Niyonkuru ◽  
Emanuel Munyeshyaka ◽  
Sibomana Madjidi ◽  
Joseph Mucumbitsi
Keyword(s):  
Antimicrobial Activity ◽  
Antibacterial Activity ◽  
Tract Infection ◽  
Health Center ◽  
Digestive Tract ◽  
Inhibition Zone ◽  
Ginger Extract ◽  
E Coli ◽  
Shigella Spp ◽  
Stool Samples

Background: Ginger (Zingiber officinale) has been used for long time due to its potential antimicrobial activity against diversity of microbial pathogens. Aims and Objectives: The study was carried out to investigate the bacteria pathogens found in digestive tract infections and assess antimicrobial activities of ginger extract to identified bacteria. Materials and Methods: Bacteriological studies were carried out on stool samples from 30 patients attending Muhoza health center. Different types of bacteria were isolated from stool samples of digestive tract infection patients by using various methods such culture, biochemical test and antimicrobial activity of ginger extracts was analyzed at INES-Ruhengeri in clinical microbiology laboratory. Results: Study findings showed isolated bacteria and antibacterial activity of Ginger. Isolated bacteria and their percentages including Escherichia coli (46.6%) which is the predominant isolated bacteria, Salmonella species (33.33%), Enterobacter spp (10.0%), Shigella spp (6.6%) and Citrobacter (3.33%) which is the least isolated bacteria. Antibacterial activity of ginger was seen on isolated bacteria, as ethanol and methanol were used for ginger oil extraction, the antibacterial activity of ginger extracts using ethanol was seen on isolated bacteria such us Citrobacter spp with 14 mm of inhibition zone, Shigella spp with 12 mm, Salmonella with 11.1 mm, E. coli with 9.5 mm and Enterobacter spp which was seen to be resistant to ginger extract using ethanol with 0.66mm of inhibition zone. For methanol extracts antibacterial activity was seen as follows: Citrobacter spp at 12 mm, Shigella spp at 11 mm, E. coli at 8 mm, salmonella spp at 6.1 mm, and Enterobacter spp with 5 mm. Enterobacter spp was seen to be the most resistant bacteria in both extracts. Conclusion: Ginger has shown to have an antibacterial activity on bacteria isolated from digestive tract infected patients. It can be used as a medicine to treat these infections. Number of researches should be done to be sure on this reality of antibacterial activity of ginger.

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