scholarly journals Photocatalytic Degradation of Fluoroquinolone Antibiotics in Solution

2022 ◽  
Author(s):  
Abniel Machín ◽  
Francisco Márquez ◽  
Kenneth Fontánez ◽  
José Duconge ◽  
María Cotto ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Photocatalytic Degradation ◽  
Visible Region ◽  
Specific Area ◽  
Bet Surface Area ◽  
Efficient Catalyst ◽  
Co Catalysts ◽  
Fluoroquinolone Antibiotics ◽  
Reduced Graphene ◽  
Photodegradation Mechanism

The photocatalytic degradation of two quinolone-type antibiotics (ciprofloxacin and levofloxacin) in aqueous solution was studied, using catalysts based on ZnO nanoparticles, which were synthesized by a thermal procedure. The efficiency of ZnO was subsequently optimized by incorporating different co-catalysts of gC3N4, reduced graphene oxide and nanoparticles of gold. The catalysts were fully characterized by electron microscopy (TEM and SEM), XPS, XRD, Raman, and BET surface area. The most efficient catalyst was 10%Au@ZnONPs-3%rGO-3%gC3N4, allowing to obtain degradations of both pollutants above 96%. This catalyst has the largest specific area, and its activity has been related to a synergistic effect, involving factors as relevant as the surface of the material and the ability to absorb radiation in the visible region, mainly produced by the incorporation of rGO and gC3N4 to the semiconductor. The use of different scavengers during the catalytic process, was used to establish the possible photodegradation mechanism of both antibiotics.

scholarly journals The Photocatalytic and Antibacterial Performance of Nitrogen-Doped TiO2: Surface-Structure Dependence and Silver-Deposition Effect

Nanomaterials ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 2261 ◽  
Author(s):  
Abdul Wafi ◽  
Erzsébet Szabó-Bárdos ◽  
Ottó Horváth ◽  
Mihály Pósfai ◽  
Éva Makó ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Visible Light ◽  
Surface Area ◽  
Photocatalytic Performance ◽  
Visible Region ◽  
Bet Surface Area ◽  
Doped Tio2 ◽  
X Ray ◽  
Nitrogen Doped ◽  
Visible Light Driven

Catalysts for visible-light-driven oxidative cleaning processes and antibacterial applications (also in the dark) were developed. In order to extend the photoactivity of titanium dioxide into the visible region, nitrogen-doped TiO2 catalysts with hollow and non-hollow structures were synthesized by co-precipitation (NT-A) and sol–gel (NT-U) methods, respectively. To increase their photocatalytic and antibacterial efficiencies, various amounts of silver were successfully loaded on the surfaces of these catalysts by using a facile photo-deposition technique. Their physical and chemical properties were evaluated by using scanning electron microscopy (SEM), transmission electron microscopy–energy dispersive X-ray spectroscopy (TEM–EDS), Brunauer–Emmett–Teller (BET) surface area, X-ray diffraction (XRD), and diffuse reflectance spectra (DRS). The photocatalytic performances of the synthesized catalysts were examined in coumarin and 1,4-hydroquinone solutions. The results showed that the hollow structure of NT-A played an important role in obtaining high specific surface area and appreciable photoactivity. In addition, Ag-loading on the surface of non-hollow structured NT-U could double the photocatalytic performance with an optimum Ag concentration of 10−6 mol g−1, while a slight but monotonous decrease was caused in this respect for the hollow surface of NTA upon increasing Ag concentration. Comparing the catalysts with different structures regarding the photocatalytic performance, silverized non-hollow NT-U proved competitive with the hollow NT-A catalyst without Ag-loading for efficient visible-light-driven photocatalytic oxidative degradations. The former one, due to the silver nanoparticles on the catalyst surface, displayed an appreciable antibacterial activity, which was comparable to that of a reference material practically applied for disinfection in polymer coatings.

scholarly journals Palladium nanoparticles anchored to anatase TiO2 for enhanced surface plasmon resonance-stimulated, visible-light-driven photocatalytic activity

2015 ◽  
Vol 6 ◽  
pp. 428-437 ◽  
Author(s):  
Kah Hon Leong ◽  
Hong Ye Chu ◽  
Shaliza Ibrahim ◽  
Pichiah Saravanan
Keyword(s):  
Electron Microscopy ◽  
Photocatalytic Activity ◽  
Surface Plasmon Resonance ◽  
Visible Light ◽  
Surface Plasmon ◽  
Plasmon Resonance ◽  
Palladium Nanoparticles ◽  
Noble Metals ◽  
Visible Region ◽  
Bet Surface Area

Freely assembled palladium nanoparticles (Pd NPs) on titania (TiO2) nano photocatalysts were successfully synthesized through a photodeposition method using natural sunlight. This synthesized heterogeneous photocatalyst (Pd/TiO2) was characterized through field emission scanning electron microscopy (FESEM), high resolution transmission electron microscopy (HRTEM), X-ray diffraction (XRD), BET surface area, UV–vis diffuse reflectance spectra (UV-DRS), Raman and photoluminescence (PL) analyses. The simple and smart synthesis anchored well the deposition with controlled Pd NPs size ranging between 17 and 29 nm onto the surface of TiO2. Thus, it gives the characteristic for Pd NPs to absorb light in the visible region obtained through localized surface plasmon resonance (LSPRs). Apparently, the photocatalytic activity of the prepared photocatalysts was evaluated by degrading the endocrine disrupting compound (EDC) amoxicillin (AMX) excited under an artificial visible light source. In the preliminary run, almost complete degradation (97.5%) was achieved in 5 h with 0.5 wt % Pd loading and the degradation followed pseudo-first-order kinetics. The reusability trend proved the photostability of the prepared photocatalysts. Hence, the study provides a new insight about the modification of TiO2 with noble metals in order to enhance the absorption in the visible-light region for superior photocatalytic performance.

scholarly journals Photocatalytic Degradation of Organic Pollutant using Reduced Graphene Oxide

2019 ◽  
Vol 8 (4S2) ◽  
pp. 870-872
Keyword(s):  
Electron Microscopy ◽  
Graphene Oxide ◽  
Photocatalytic Degradation ◽  
Reduced Graphene Oxide ◽  
Organic Pollutant ◽  
X Ray Diffraction ◽  
X Ray ◽  
Reduced Graphene ◽  
Vis Spectroscopy ◽  
Scaning Electron Microscopy

A simple eco friendly preparation of reduced graphene oxide from graphene oxide using strawberry extract is reported. As prepared reduced graphene oxide were characterized by X-Ray Diffraction, UV-Vis spectroscopy, Scaning electron microscopy and degradation performane of MB. The reduced graphene oxide was effectively degradation of MB.

scholarly journals Synthesis of ZnO nanoparticles using peels of Passiflora foetida and study of its activity as an efficient catalyst for the degradation of hazardous organic dye

2021 ◽  
Vol 3 (5) ◽  
Author(s):  
Mujahid Khan ◽  
Pundlik Ware ◽  
Navinchandra Shimpi
Keyword(s):  
Electron Microscopy ◽  
Zno Nanoparticles ◽  
Metal Salt ◽  
Organic Pollutant ◽  
Good Choice ◽  
Bet Surface Area ◽  
Zno Nps ◽  
Efficient Catalyst ◽  
X Ray ◽  
Passiflora Foetida

AbstractCreating a sustainable and effective approach to handling organic contaminants from industrial waste is an ongoing problem. In the present study, ZnO nanoparticles (ZnO NPs) were synthesized under a controlled ultrasound cavitation technique using the extract of Passiflora foetida fruit peels, which act as a reducing (i.e., reduction of metal salt) and stabilizing agent. The formation of monodispersed and hexagonal morphology (average size approximately 58 nm with BET surface area 30.83m2/g). The synthesized ZnO NPs were characterized by a various technique such as UV–visible spectroscopy, X-ray diffraction (XRD), Fourier-transform infrared (FTIR), Scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), Transmission electron microscopy (TEM), Thermogravimetric analysis (TGA) and Dynamic light scattering (DLS). Further, the XRD pattern confirmed the hexagonal wurtzite structure of synthesized ZnONPs. The ZnO NPs exhibit excellent degradation efficiency towards organic pollutant dyes, i.e., Methylene blue (MB) (93.25% removal) and Rhodamine B (91.06% removal) in 70 min, under natural sunlight with apparent rate constant 0.0337 min−1 (R2 = 0.9749) and 0.0347 min−1 (R2 = 0.9026) respectively.Zeta potential study shows the presence of a negative charge on the surface of ZnO NPs. The use of green synthesized ZnO NPs is a good choice for wastewater treatment, given their high reusability and photocatalytic efficiency, along with adaptability to green synthesis.

scholarly journals Enhanced Photocatalytic Performance of Nb Doped TiO2/reduced Graphene Oxide Nanocomposites Over Rhodamine B Dye Under Visible Light Illumination

2021 ◽  
Author(s):  
N. Prabhakarrao ◽  
K.V. Divya Lakshmi ◽  
G. Divya ◽  
G. Jaishree ◽  
Imandi Manga Raju ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Graphene Oxide ◽  
Visible Light ◽  
Reduced Graphene Oxide ◽  
Rhodamine B ◽  
Photocatalytic Performance ◽  
Bet Surface Area ◽  
Light Illumination ◽  
Reduced Graphene ◽  
Rhodamine B Dye

Abstract The present study discusses the synthesis of Nb doped TiO2/reduced Graphene Oxide (GO) intercalated nanocomposites via sol-gel route at a lower temperature by using different loading amounts of GO (1 to 10 wt%). The synthesized composite materials were further characterized by copious instruments such as X-ray Diffractometer, UV-vis Diffuse Reflectance Spectroscopy, Scanning Electron Microscopy, Transmission Electron Microscopy, BET surface area analysis, Raman and FT-Infrared Spectroscopy. The experimental results stated that the Nb doped TiO2 nanoparticles uniformly distributed on the surface of reduced Graphene Oxide (rGO) with an interfacial linking bond between TiO2 and rGO. Later, the photocatalytic degradation of Rhodamine B dye using produced materials under visible light irradiations was examined. These results reveal that Nb doped TiO2/rGO nanocomposites exhibited better photocatalytic performance than Nb doped TiO2 for the removal of Rhodamine B dye. However, among all, the nanocomposite having 5% of GO content achieves the highest degradation rate for Rhodamine B dye approximately 98% under visible light exposure. Overall, the unique properties such as electron accepting and transporting properties of GO in the nanocomposites help to enhance photocatalytic activity by minimizing the charge carrier’s recombination rate.

scholarly journals Synthesis of CaFe2O4-NGO Nanocomposite for Effective Removal of Heavy Metal Ion and Photocatalytic Degradation of Organic Pollutants

Nanomaterials ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1471
Author(s):  
Manmeet Kaur ◽  
Manpreet Kaur ◽  
Dhanwinder Singh ◽  
Aderbal C. Oliveira ◽  
Vijayendra Kumar Garg ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Photocatalytic Degradation ◽  
Metal Ion ◽  
Bet Surface Area ◽  
Calcium Ferrite ◽  
Maximum Adsorption Capacity ◽  
X Ray ◽  
Effective Removal ◽  
Nitrogen Doped Graphene ◽  
Doped Graphene

This paper reports the successful synthesis of magnetic nanocomposite of calcium ferrite with nitrogen doped graphene oxide (CaFe2O4-NGO) for the effective removal of Pb(II) ions and photocatalytic degradation of congo red and p-nitrophenol. X-ray diffraction (XRD), Fourier transform infrared (FT-IR), transmission electron microscopy (TEM), and scanning electron microscopy-energy dispersive X-ray (SEM-EDX) techniques confirmed the presence of NGO and CaFe2O4 in the nanocomposite. The Mössbauer studies depicted the presence of paramagnetic doublet and sextet due to presence of CaFe2O4 NPs in the nanocomposite. The higher BET surface area in case of CaFe2O4-NGO (52.86 m2/g) as compared to CaFe2O4 NPs (23.45 m2/g) was ascribed to the effective modulation of surface in the presence of NGO. Adsorption followed the Langmuir model with maximum adsorption capacity of 780.5 mg/g for Pb(II) ions. Photoluminescence spectrum of nanocomposite displayed four-fold decrease in the intensity, as compared to ferrite NPs, thus confirming its high light capturing potential and enhanced photocatalytic activity. The presence of NGO in nanocomposite offered an excellent visible light driven photocatalytic performance. The quenching experiments supported ●OH and O2●− radicals as the main reactive species involved in carrying out the catalytic system. The presence of Pb(II) had synergistic effect on photocatalytic degradation of pollutants. This study highlights the synthesis of CaFe2O4-NGO nanocomposite as an efficient adsorbent and photocatalyst for remediating pollutants.

scholarly journals Photocatalytic Degradation of Sulfolane Using a LED-Based Photocatalytic Treatment System

Catalysts ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 624
Author(s):  
Sripriya Dharwadkar ◽  
Linlong Yu ◽  
Gopal Achari
Keyword(s):  
Photocatalytic Degradation ◽  
Oil And Gas ◽  
Light Emitting Diode ◽  
Tap Water ◽  
Aqueous Media ◽  
Ultrapure Water ◽  
Light Emitting ◽  
Degradation Rates ◽  
Reduced Graphene ◽  
The Impact

Sulfolane is an emerging industrial pollutant detected in the environments near many oil and gas plants in North America. So far, numerous advanced oxidation processes have been investigated to treat sulfolane in aqueous media. However, there is only a few papers that discuss the degradation of sulfolane using photocatalysis. In this study, photocatalytic degradation of sulfolane using titanium dioxide (TiO2) and reduced graphene oxide TiO2 composite (RGO-TiO2) in a light-emitting diode (LED) photoreactor was investigated. The impact of different waters (ultrapure water, tap water, and groundwater) and type of irradiation (UVA-LED and mercury lamp) on photocatalytic degradation of sulfolane were also studied. In addition, a reusability test was conducted for the photocatalyst to examine the degradation of sulfolane in three consecutive cycles with new batches of sulfolane-contaminated water. The results show that LED-based photocatalysis was effective in degrading sulfolane in waters even after three photocatalytic cycles. UVA-LEDs displayed more efficient use of photon energy when compared with the mercury lamps as they have a narrow emission spectrum coinciding with the absorption of TiO2. The combination of UVA-LED and TiO2 yielded better performance than UVA-LED and RGO-TiO2 for the degradation of sulfolane. Much lower sulfolane degradation rates were observed in tap water and groundwater than ultrapure water.

scholarly journals ZnO Nanoparticles with Controllable Ce Content for Efficient Photocatalytic Degradation of MB Synthesized by the Polyol Method

Catalysts ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 71
Author(s):  
Gregorio Flores-Carrasco ◽  
Micaela Rodríguez-Peña ◽  
Ana Urbieta ◽  
Paloma Fernández ◽  
María Eugenia Rabanal
Keyword(s):  
Electron Microscopy ◽  
Photocatalytic Degradation ◽  
Doping Concentration ◽  
Polyol Method ◽  
Transmission Microscopy ◽  
Uv Illumination ◽  
Transmission Electron ◽  
Optical Luminescence ◽  
Pl Emission ◽  
Ce Content

This paper reports on the synthesis of Ce-doped ZnO (CZO) nanoparticles (NPs) by an alternative polyol method at low temperature. The method, facile and rapid, uses acetate-based precursors, ethylene glycol as solvent, and polyvinylpyrrolidone as capping agent. The effects of the Ce-doping concentration (ranging from 0 to 8.24 atomic%) on the structural, morphological, compositional, optical, luminescence, and photocatalytic properties of the NPs were investigated by several techniques. The structural findings confirmed that the CZO NPs have a typical hexagonal wurtzite-type structure with a preferred orientation along the (101) plane. The results obtained by Field Emission Scanning Electron Microscopy (FESEM) and Transmission Electron Microscopy (TEM) revealed that the NPs size decreased (from ~30 to ~16 nm) with an increase in the Ce-doping concentration. Energy Dispersive X-Ray Spectroscopy (EDS) and High Resolution Transmission Microscopy (HRTEM) results confirmed the incorporation of Ce ions into the ZnO lattice. Ce-doping influences the photoluminescence (PL) emission compared to that of pure ZnO. The PL emission is related to the presence of different kinds of defects, which could take part in charge transfer and/or trapping mechanisms, hence playing an essential role in the photocatalytic activity (PCA). In fact, in this work we report an enhancement of PCA as a consequence of Ce-doping. In this sense, the best results were obtained for samples doped with 3.24 atomic%, that exhibited a photocatalytic degradation efficiency close to 99% after 60 min ultraviolet (UV) illumination, thus confirming the viability of Ce-doping for environmental applications.

scholarly journals Algal magnetic nickel oxide nanocatalyst in accelerated synthesis of pyridopyrimidine derivatives

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Javad Moavi ◽  
Foad Buazar ◽  
Mohammad Hosein Sayahi
Keyword(s):  
Nickel Oxide ◽  
Spherical Shape ◽  
Marine Macroalgae ◽  
Bet Surface Area ◽  
Nickel Oxide Nanoparticles ◽  
One Pot ◽  
Efficient Catalyst ◽  
Coating Agent ◽  
Synthesis Conditions ◽  
Nio Nps

AbstractThis research presents a novel biological route for the biosynthesis of nickel oxide nanoparticles (NiO NPs) using marine macroalgae extract as a reducing and coating agent under optimized synthesis conditions. XRD and TEM analyses revealed that phytosynthesized NiO NPs are crystalline in nature with a spherical shape having a mean particle size of 32.64 nm. TGA results indicated the presence of marine-derived organic constituents on the surface of NiO NPs. It is found that biogenic NiO NPs with BET surface area of 45.59 m2g−1 is a highly efficient catalyst for benign one-pot preparation of pyridopyrimidine derivatives using aqueous reaction conditions. This environmentally friendly procedure takes considerable advantages of shorter reaction times, excellent product yields (up to 96%), magnetically viable nanocatalyst (7 runs), low catalyst loadings, and free toxic chemical reagents.

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