Activity For Degradation Of Tetracycline Research Articles

One-pot decoration of CdS and CdMoO4 nanoparticles on g-C3N4 nanoplates: Boosted photocatalytic degradation of tetracycline

Photocatalytic water detoxification has been a hot-spot research field in recent years. In this regard, CdS and CdMoO4 nanoparticles were decorated on g-C3N4 nanoplates via a one-pot hydrothermal route. The morphology, structure, phase, surface properties, electrochemical, and optical properties of the resultant materials were identified by XRD, FT-IR, UV–vis DRS, FESEM, TEM, HRTEM, XPS, EDX, EIS, BET, BJH, and PL analyses. The optimum ternary nanocomposite exhibited boosted activity for degradation of tetracycline (TC), Congo red (CR), methylene blue (MB), methyl orange (MO), and malachite green (MG) upon visible light, which was 41.6, 29.0, 16.1, 27.4, and 38.2 times higher than pristine g-C3N4. The UV–vis DRS, EIS, PL, and BET analyses attributed the boosted activity to the generation of more charge carriers, promoted segregation and transfer of charges, and extended surface area. The quenching experiments confirmed the crucial role of holes and superoxide anion radicals in the degradation reaction. Eventually, based on the outcomes, a probable mechanism for the boosted photocatalytic ability was discussed.

Construction of S-scheme heterojunction WO3/Bi2O4 with significantly enhanced visible-light-driven activity for degradation of tetracycline

Recently, S-scheme heterojunctions have drawn much attention due to their unique interface charge transfer pathway and resultantly excellent photocatalytic performance. Herein, a novel 2D/1D S-scheme heterojunction photocatalyst was constructed by loading WO3 nanosheets on the surface of rod-shaped Bi2O4. The S-scheme charge transfer mechanism between WO3 and Bi2O4 was affirmed by the results of the Fermi level and in situ irradiated X-ray photoelectron spectroscopy (XPS). The construction of the S-scheme heterostructure significantly accelerated the separation and migration of the photoinduced electrons and holes in WO3/Bi2O4 and preserved the photogenerated holes and electrons with high redox capability in the valence band of WO3 and the conduction band of Bi2O4. Compared to the pristine WO3 and Bi2O4, the heterojunction WO3/Bi2O4 exhibits significantly boosted activity for the degradation of tetracycline (TC) under visible-light irradiation. The photodegradation efficiency of TC is up to 90 %. The degradation rate constant (0.0587 min−1) for WO3/Bi2O4 toward TC is 2.21 and 28.34 times those for Bi2O4 and WO3. The improved activity of WO3/Bi2O4 is attributed to S-scheme interfacial charges migration pathway, unique 2D/1D heterostructure and exceptional visible light absorption ability. Additionally, WO3/Bi2O4 shows good photochemical stability and acid-alkali suitability. The common inorganic ions and humus (fulvic acid) in natural water have little influence on the photodegradation of TC. This work brings a new idea for constructing heterojunction photocatalysts with high activity for boosted TC photodegradation.

A visible light responsive Bi2S3/MIL-53(Fe) heterojunction with enhanced photocatalytic activity for degradation of tetracycline

Metal-organic frameworks (MOFs), as a new type of crystal materials, are considered a kind of promising photocatalysts. In this work, a novel Bi2S3/MIL-53(Fe) heterojunction photocatalyst was successfully prepared via a facile two-step method (hydrothermal and water bath). The characterization means, including XRD, SEM-EDS, FT-IR, XPS, PL, and UV–Vis, were employed to analyze the structural and morphological properties of Bi2S3/MIL-53(Fe). The photocatalytic performance of Bi2S3, MIL-53(Fe), and Bi2S3/MIL-53(Fe) was evaluated by the removal efficiency of the photocatalytic degradation of tetracycline (TC, 10 mg/L) under visible light irradiation (λ > 420 nm). The results show that the photocatalyst BSM-10 (the mass ratio of Bi2S3 to MIL-53(Fe) is 10:90) exhibits improved photocatalytic performance compared to Bi2S3 and MIL-53(Fe), showing the optimum photocatalytic activity (the degradation efficiency of TC is 90.9% within 120 min), and the corresponding first-order reaction rate constant is about 3 and 2 times higher than that of MIL-53(Fe) and Bi2S3, respectively. The improvement in photocatalytic activity is attributable to the efficacious separation of photogenerated electron-hole pairs and significant acceleration of charge transfer rate. Based on the free radical trapping experiment and ESR test results, combined with the band structure of MIL-53 (Fe) and Bi2S3, we speculate that a heterojunction is formed between MIL-53 (Fe) and Bi2S3, and the proposed Z scheme mechanism can well explain the enhanced catalytic activity of BSM-10. The Bi2S3/MIL-53 (Fe) heterojunction photocatalyst synthesized in this work has potential application value for removing the typical pollutant tetracycline from water.

Edge electron-rich carbon nitride via π-acceptor frame with high-efficient charge separation for photocatalytic hydrogen evolution and environmental remediation

Carbon nitride (g-C3N4) has broad application prospects in photocatalytic hydrogen production, but its photocatalytic efficiency is not ideal because of the rapid recombination of photogenerated electrons and holes. Herein, we developed a green strategy to fabricate hydroxyls and carbon-bridging co-modified g-C3N4 (CCN-OH) through a one-pot copolymerization and hydrothermal treatment. Experiments and density functional theory (DFT) calculations illustrated that carbon substitution of partial bridge nitrogen can improve the degree of electron delocalization to enhance the electron supply capacity of g-C3N4, and the exsitence of the electron-withdrawing OH group induces electron migration from carbon nitride to hydroxyl group, which further improves the efficiency of photogenerated charge separation. In addition, CCN-OH possess narrower band structure, resulting in an increased visible light utilization efficiency. The as-synthesized CCN-OH9 samples displayed an excellent photocatalytic activity for degradation of tetracycline with apparent reaction rate constant (k) of 0.018 min−1 and photocatalytic hydrogen evolution of 1880.3 μmol g-1h−1, which was respectively 2.2 and 9.8 times higher than that of CN.

Facile synthesis of amino-functionalized indium-based metal–organic frameworks and their superior light photocatalytic activity for degradation of tetracycline in water

The synthesized MIL-68(In)-NH2 photocatalyzed the degradation of tetracycline under visible light irradiation.

Cu3P nanoparticles decorated hollow tubular carbon nitride as a superior photocatalyst for photodegradation of tetracycline under visible light

• Cu 3 P/HTCN composite was successfully prepared via a simple solvothermal method. • Unique hollow tubular structure greatly improves the light harvesting ability. • Cu 3 P/HTCN composite shows superior photocatalytic activity for degradation of TC. • Cu 3 P effectively inhibits the rapid recombination of photogenerated carrier of HCCN. The construction of stable, efficient and economical visible-light-driven photocatalyst is a practical strategy to deal with antibiotic water contamination. Herein, Cu 3 P nanoparticles/hollow tubular carbon nitride (HTCN) composite was successfully prepared and the photocatalytic activity of Cu 3 P/HTCN was evaluated with tetracycline (TC) as the degradation target antibiotic. Among them, the 6% Cu 3 P/HTCN exhibited optimal photocatalytic degradation rate (96.9% in 40 min), which was 8.3 times higher than that of pure HTCN. The enhancement of photocatalytic performance by Cu 3 P/HTCN is attributed to the introduction of Cu 3 P nanoparticles can not only increase the specific surface area of HTCN to provide abundant reaction sites, but also enhance the capture ability of incident light and promote the high-speed separation and transfer of photogenerated charges. In addition, the electron spin resonance (ESR) technology was used to further confirm that the main active species during the photocatalytic degradation of TC. Furthermore, the possible intermediates in photocatalytic degradation of TC by Cu 3 P/HTCN was the identified with liquid chromatography-mass spectrometry (LC-MS). This work provides an effective way for constructing HTCN-based composite materials for photocatalytic application.

One-Pot Fabrication of K-Doped g-C3N4/SiO2Composite with Enhanced Photocatalytic Activity for Degradation of Tetracycline

K-doped g-C3N4/SiO2composite (SiO2/K-CN) was synthesized by a facile thermal polymerization with potassium chloride, melamine and nano-silica as raw materials. The as-prepared SiO2/K-CN was characterized by various measures. The photocatalytic activity of SiO2/K-CN was tested via the photocatalytic degradation of tetracycline under visible-light irradiation. The results showed that the specific surface area of SiO2/K-CN catalyst was 28.16m2/g, which is larger than that of pristine K-doped g-C3N4. Both K-doping and silica-combination can reduce the recombination rate of photo-generated electrons-holes pairs and broaden the region of visible light-harvesting. Compared with the pristine K-doped g-C3N4 and composite SiO2/g-C3N4, SiO2/K-CN exhibits distinctly higher photocatalytic activity for degradation of tetracycline. The enhanced photocatalytic performance of SiO2/K-CN is attributed to the increased specific surface area and the synergistic effect of K-doping and silica-combination in both accelerating separation of charged carries and improving visible light-absorption. During photocatalytic degradation of tetracycline, superoxide radicals play the most important role, followed by holes.SiO2/K-CN complex has excellent stability and shows promising application in photocatalytic degradation of organic contaminants in water.

One-Pot Fabrication of K-Doped g-C3N4/SiO2Composite with Enhanced Photocatalytic Activity for Degradation of Tetracycline

K-doped g-C3N4/SiO2composite (SiO2/K-CN) was synthesized by a facile thermal polymerization with potassium chloride, melamine and nano-silica as raw materials. The as-prepared SiO2/K-CN was characterized by various measures. The photocatalytic activity of SiO2/K-CN was tested via the photocatalytic degradation of tetracycline under visible-light irradiation. The results showed that the specific surface area of SiO2/K-CN catalyst was 28.16m2/g, which is larger than that of pristine K-doped g-C3N4. Both K-doping and silica-combination can reduce the recombination rate of photo-generated electrons-holes pairs and broaden the region of visible light-harvesting. Compared with the pristine K-doped g-C3N4 and composite SiO2/g-C3N4, SiO2/K-CN exhibits distinctly higher photocatalytic activity for degradation of tetracycline. The enhanced photocatalytic performance of SiO2/K-CN is attributed to the increased specific surface area and the synergistic effect of K-doping and silica-combination in both accelerating separation of charged carries and improving visible light-absorption. During photocatalytic degradation of tetracycline, superoxide radicals play the most important role, followed by holes.SiO2/K-CN complex has excellent stability and shows promising application in photocatalytic degradation of organic contaminants in water.

Novel photocatalytic performance of magnetically recoverable MnFe2O4/BiVO4 for polluted antibiotics degradation

In the study, we successfully decorated MnFe2O4 on BiVO4 to highly improve its photocatalytic activity for degradation of tetracycline as well as its magnetically recovery. The decoration of MnFe2O4 on BiVO4 led to formation of MnFe2O4/BiVO4 Z scheme heterojunction to effectively prevent the charge recombination in each material. Upon visible light, the MnFe2O4/BiVO4 heterojunction produced significant available amounts of e− and h+ existing in the conduction band of the MnFe2O4 and the valence band of the BiVO4, respectively. These produced e− on the conduction band of the MnFe2O4, which reduction potential was approximately −0.41 eV, exhibited strong reduction potential reducing oxygen to produce •O2− radicals while h+ on the valence band of the BiVO4, which oxidation potential was 2.77 eV, showed strong oxidation potential oxidizing water and hydroxyl groups to produce •OH radicals. These generated active oxygen radicals effectively degraded TC in water (~92%). The used photocatalysts were easily recovered from photocatalytic suspension using an external magnet due to high magnetically activity of the MnFe2O4, which tightly bonded with BiVO4 in the MnFe2O4/BiVO4 heterojunction. Finally, the recovered MnFe2O4/BiVO4 heterojunction was very active and stable for tetracycline degradation in long-term process.

Preparation of pyramidal SnO/CeO2 nano-heterojunctions with enhanced photocatalytic activity for degradation of tetracycline

Pyramidal SnO/CeO2 nano-heterojunction photocatalysts were successfully synthesized via a facile hydrothermal method. The structural characterization was investigated by using common characterization tools. The content of SnO affected the morphology and photocatalytic performance of the SnO/CeO2 nano-heterojunctions. With the increase of the SnO content, the morphology of the samples changed from a spherical structure to a pyramidal structure. The photocurrent of the SnO/CeO2 (1:6) sample was about 36 times that of pure CeO2. With SnO/CeO2 (1:6) as the photocatalyst, the degradation rate of tetracycline (TC) was 99% within 140 min under visible light and after five cyclic tests the photocatalytic efficiency of TC remained at 98%, which suggests that the SnO/CeO2 (1:6) nano-heterojunction had a high photocatalytic efficiency and stable photocatalytic performance. These results indicate that SnO/CeO2 (1:6) nano-heterojunction possesses broad prospects for industrial application.

In-situ growth of Zr1-0.5xCdxW2O8 on ZrW2O8/CdWO4 manufactured by electron beam irradiation with superior photocatalytic activity for degradation of tetracycline under visible light

In-situ growth of Zr1-0.5xCdxW2O8 on ZrW2O8/CdWO4 manufactured by electron beam irradiation with superior photocatalytic activity for degradation of tetracycline under visible light

Designed Redox Ions Pairs imprinted photocatalyst of Fe3+@PoPD/TiO2/HNTs for enhanced photocatalytic activity

ABSTRACT In this study, Fe3+@PoPD/TiO2/HNTs composite photocatalyst was successfully prepared by sol-gel method and ion-imprinting technique. The composite photocatalysts were characterised by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), ultraviolet X-ray photoelectron spectroscopy (XPS) and ultraviolet-visible diffuse reflectance spectroscopy (UV-vis DRS). The photocatalytic activity of the composite photocatalyst was studied by simulating the degradation of tetracycline under sunlight. The results showed that the prepared composite photocatalyst had obvious activity for tetracycline degradation under simulated solar irradiation, and Fe3+@PoPD/TiO2/HNTs-1 had the best performance. The photodegradation rate can reach 91% in 90 min. This work may provide a promising approach for wastewater treatment by utilisation of ion imprinting technique and increasing photocatalytic performance of TiO2.

Facile Fabrication of C-TiO2 Nanocomposites with Enhanced Photocatalytic Activity for Degradation of Tetracycline.

Visible-lightdriven C–TiO2 nanocomposites were prepared via a simple calcination and acid etching process. The C–TiO2 nanocomposites were characterized by X-ray photoelectron spectroscopy, Raman spectroscopy, X-ray diffraction, transmission electron microscopy, and high-resolution TEM. The results showed that TiO2 nanoparticles were combined with a porous carbon layer through surface C–O groups, which facilitates the strong interface interaction. The interface combination of nano-TiO2 and carbon material increases the specific surface area of nano-TiO2, widens the range of light response, and improves the efficiency of light-induced electron migration. The visible-light photocatalytic activity of the prepared photocatalyst was evaluated by the decomposition of tetracycline aqueous solution. Compared with that of pure TiO2, the photocatalytic activity of C–TiO2 nanocomposites was significantly improved. Furthermore, a possible photocatalytic mechanism was also tentatively proposed. This work can promote the development of active photocatalysts under solar light for the photodegradation of environmental pollutants.

Facile preparation of nanostructured NixZn1−xFe2O4/CNTs composites with enhanced visible-light-driven photocatalytic activity for tetracycline degradation

NixZn1−xFe2O4/CNTs composite photocatalysts were prepared via a facile hydrothermal method, and their physical and chemical properties were investigated. The effect of different Ni doping amounts on the photocatalytic activity of NixZn1−xFe2O4 and Ni0.5Zn0.5Fe2O4/CNTs photocatalysts containing different amounts of carbon nanotubes (CNTs) were investigated for their ability to degrade tetracycline (TC) in wastewater. The results showed that Ni0.5Zn0.5Fe2O4/CNTs (5% CNTs) had the highest photocatalytic activity, achieving a TC degradation of 96%. The origin of the excellent performance of the photocatalysts, as well as the photodegradation mechanism, were also discussed. Effective electron–hole separation is believed to be responsible for the significantly improved photocatalytic activity. After four photocatalytic degradation experiments, the composite photocatalyst retained its high photocatalytic activity, and the results showed that the composite photocatalysts were highly stable and could be magnetically separated.

Enhanced visible-light-driven photocatalytic performance of AgNbO3 cubes with a high-energy (001) facet

AgNbO3 cubes with an exposed high-energy (001) facet were prepared by hydrothermal treatment of Ag2O–Nb2O5–NH4HF2 aqueous suspension. The crystal phase, surface microstructure, and optical properties of the samples were characterized by X-ray diffraction, field-emission scanning electron microscopy, transmission electron microscopy, and UV–vis diffuse reflectance spectroscopy. The energy band structure and charge carrier separation efficiency were investigated by photoelectrochemical measurements. In comparison with AgNbO3 powder, whose surface was dominated by a low-energy (114) facet, the AgNbO3 cubes had superior visible-light-driven photocatalytic activity for degradation of tetracycline because of the greater redox ability and more efficient separation of photogenerated electrons and holes. The surface F− ions had no influence on the photocatalytic reactions. Radical trapping experiments demonstrated that the superoxide radical played a decisive role in the photodegradation of tetracycline.

Synthesis plasmonic Bi/BiVO4 photocatalysts with enhanced photocatalytic activity for degradation of tetracycline (TC)

Abstract In recent years, the excessive use of antibiotics has become a serious problem for human health. BiVO4 regarded as one of the most promising visible-light-driven photocatalysts was used to degrade the antibiotics. In this paper, we fabricated Bi/BiVO4 plasmonic photocatalysts which enhanced the photocatalytic activity of BiVO4 for degradation of tetracycline (TC) antibiotic. The Bi/BiVO4 photocatalysts were characterized by X-ray diffraction, X-ray photoelectron spectroscopy, scanning electron microscopy, transmission electron microscopy and high-resolution transmission electron microscopy. In addition, the photocatalytic experiment results show that the 0.04-Bi/BiVO4 sample has the best photocatalytic activity for 2 times than the pure BiVO4 photocatalyst. The cycle experiments, after four repetitions of the experiments, showed the sample still maintained a high photocatalytic activity. Finally, the photocatalytic reaction mechanism was also studied by free radical capture experiments and electron paramagnetic resonance spectroscopy.

In-suit preparation of CdSe quantum dots/porous channel biochar for improving photocatalytic activity for degradation of tetracycline

Abstract In this paper, a simple in-suit method was used to load CdSe quantum dots (QDs) onto HTC (abbreviated as Hydrothermal biochar, HTC) to form CdSe/HTC composites. Fourier transform infrared spectrometer and X-ray photoelectron spectroscopy were used to detect and analyze the surface valence and composition of CdSe/HTC composites. The photocatalytic degradation activity was judged by photodegrading tetracycline (TC). Compared with pure CdSe quantum dots, the best photocatalytic degradation efficiency of CdSe/HTC complex containing 15% HTC was 73%, which was attributed to the high carrier transport efficiency of HTC and the inhibition reorganization of photogenerated electron-hole pairs. More importantly, the hydrothermal biochar used in this paper was extracted from waste biomass and had the characteristics of economy, environmental protection and high utilization rate, and was in line with the basic viewpoint of sustainable use of resources.

Facile Synthesis of Ag/AgCl Grafted AgBi(MoO4)2 with Enhanced Photocatalytic Performance Under Visible Light

Silver nanoparticles (NPs) and related semiconductors are a family of very important and widely applied photocatalysts. However, the preparation of high stability and activity of this photocatalyst is still a challenge. In this work, we report a stable Ag/AgCl/AgBi(MoO[Formula: see text] heterojunction photocatalyst fabricated via a simple in situ anion-exchange reaction followed by the photoreduction treatment. In the treatment of tetracycline (TC) wastewater under visible light, the AC-0.4 sample (prepared with 0.4[Formula: see text]mmol KCl) exhibits the significantly improved activity (degradation ratio, DR of 71.3%) compared with the pristine AgBi(MoO[Formula: see text] (30% DR) and Ag/AgCl sample (synthesized by the photoreduction of AgCl) (37% DR) under identical experimental conditions. This activity promotion is from the fast interfacial electron transfer between the heterojunction phases of AgCl/AgBi(MoO[Formula: see text] and the SPR effect of Ag NPs. After five successive recycles, the AC-0.4 sample still maintains good stability and activity for TC degradation, which shows a great potential to be used in practical application. Through the ESR and controlled scavenged experiments, we found the [Formula: see text]OH and [Formula: see text]O[Formula: see text] are the major reactive intermediate species in the TC photodegradation reaction. Our work provides a new insight into the synthesis of stable and high efficient Ag-based heterojunction photocatalysts for the application of wastewater treatment.

Visible light responsive Bi2WO6/BiOCl heterojunction with enhanced photocatalytic activity for degradation of tetracycline and rohdamine B

Visible light responsive Bi2WO6/BiOCl heterojunctions with varying molar ratio of WO66− to Cl− were successfully fabricated by a facile one-step hydrothermal method. The photocatalytic performance of as-synthesized heterojunctions was investigated through degradation of rohdamine B (RhB) and tetracycline (TC). Results showed that the Bi2WO6/BiOCl heterojunction exhibited markedly improved degradation efficiency under visible light irradiation compared with bare BiOCl and Bi2WO6, which can be attributed to the synergistic effect between Bi2WO6 and BiOCl. The heterojunction formed at the interface of Bi2WO6 and BiOCl results in the effective separation of photo-generated electron-hole pairs and contributes to the improved photocatalytic activity.

Visible-light-driven Ag/Bi3O4Cl nanocomposite photocatalyst with enhanced photocatalytic activity for degradation of tetracycline

In this study, a novel Ag/Bi3O4Cl photocatalyst has been synthesized by a facile photodeposition process. Its photocatalytic performance was evaluated from the degradation of tetracycline (TC) under visible light irradiation (λ > 420 nm). The 1.0 wt% Ag/Bi3O4Cl photocatalyst could significantly enhance the degradation of TC compared with pure Bi3O4Cl, with the degradation level reaching 94.2% in 120 minutes. The enhancement of photocatalytic activity could be attributed to the synergetic effect of the photogenerated electrons (e−) of Bi3O4Cl and the surface plasmon resonance (SPR) caused by Ag nanoparticles, which could improve the absorption capacity of visible light and facilitate the separation of photogenerated electron–hole pairs. In addition, electron spin resonance (ESR) analysis and trapping experiments demonstrated that the superoxide radicals (˙O2−), hydroxyl radicals (˙OH) and holes (h+) played crucial roles in the photocatalytic process of TC degradation. The present work provides a promising approach for the development of highly efficient photocatalysts to address current environmental pollution, energy issues and other related areas.