Photodegradation Of Tetracycline Research Articles

Enhanced light harvesting ability in hollow Pt/TiO2 nanoreactor for boosting tetracycline photodegradation

Utilizing solar energy to decompose tetracycline (TC) is a green strategy to treat wastewater. Herein, a heterogeneous hollow structured TiO2 decorated Pt nanoparticles were successfully designed and synthesized via hard-template approach and photo-deposition process toward TC photodegradation. The Pt nanoparticles loaded on the surface of hollow structured TiO2 can increase the visible light absorption due to the local surface plasmon resonance (LSPR) effect. Furthermore, owing to the tough electron oscillation of the LSPR excitation, the plasmonic hot holes on the surface of Pt nanoparticles can capture the electrons of TiO2, effectively facilitating the separation of photo-excited charge carriers because of the formation of Schottky junction constructed between Pt and TiO2. Combined the natural merits of shorten conveying path of charge carriers and physical structural stability for hollow structure, the optimal Pt/TiO2 hetero-junction hybrid showed superior photocatalytic activity and durability for TC photodegradation with the degradation efficiency of 93.8 ​% after 30 ​min and the rate constant of 0.09196 min−1 under 300 ​W Xe lamp irradiation. This work displays a heterogeneous hybrids catalyst based on eco-friendly metal and semiconductor materials which can be used in the fields including without limitation TC photodegradation.

Facile synthesis of magnetic resorcinol–formaldehyde resin Fe3O4@RF-Au composites for enhanced tetracycline photodegradation with simultaneous H2O2 production

Facile synthesis of magnetic resorcinol–formaldehyde resin Fe3O4@RF-Au composites for enhanced tetracycline photodegradation with simultaneous H2O2 production

Synthesis of a novel cost-effective double-ligand Zr-based MOF via an inverted modulator strategy towards enhanced adsorption and photodegradation of tetracycline

Developing visible-light response photocatalysts with high activity and adsorption alongside sustainability is vitally important to environmental restoration. Here, we fabricated a novel metal organic framework (MOF) with cost-effective double-ligands (fumaric acid and 2-aminoterephthalic acid as ligand precursors, denoted as MA-MOF) via a facile solvothermal method. Specifically, crystalline [Zr6O4(OH)4(fumarate)6] (MOF-801) can be only formed with monocarboxylic acids as modulators. Therefore, in the construction of crystalline double-ligand MA-MOF, the absence of monocarboxylic acid modulators successfully prevents the formation of crystalline MOF-801. Instead, the crystalline double-ligand MA-MOF is formed. Properties of MA-MOFs including the surface area, porosity, charge transfer resistance, and energy level position can be adjusted via altering the ratio of ligands. The optimal sample, MA-MOF2 (prepared with a molar ratio of fumaric acid and 2-aminoterephthalic acid being 2:1), shows a total 94.6% removal of tetracycline via adsorption and photodegradation, far exceeding the corresponding single-ligand counterparts. This work proposes an innovative inverted modulator strategy for constructing double-ligand MOFs.

Precise structure-tailoring of multicomponent nanocatalysts enabled by continuous flow-controlled flash nanoprecipitation technique

Nanostructured catalysts with diverse compositions offer an exciting prospect for various catalytic applications. The precise control of nanostructures allows to tune the physicochemical properties of nanocatalysts and improve their performance. However, most preparative methods rely on conventional batch systems, which require tedious procedures and cause low productivity. Herein, we reported a novel engineered flash nanoprecipitation (FNP) technique to synthesize well-structured nanocatalysts in a continuous-flow procedure with intelligent operation and high productivity, in which a series of multicomponent bismuth oxyhalides (BiOClxBr1-x) were demonstrated as the model catalysts. This method was established on the uninterrupted continuous synthesis of BiOClxBr1-x with precisely controlled microstructure by simply altering the flow rate ratio of precursor fluids in the reactor. The computational fluid dynamics (CFD) simulation showed that the automized flow setup could achieve the accurate control over the intensified fluid mixing. Significantly, a volcano relationship between the halogen compositions and catalytic activities toward photodegradation of tetracycline (TC) was observed, which indicated that the structural changes enabled band structure-dependent regulation. The FNP-processed BiOCl0.75Br0.25 possessed a balanced redox ability and light absorption, thus located at the peak of volcano with a five-fold enhancement of intrinsic photocatalytic activity. Overall, this work provides a promising prospect of continuous-flow technique in the engineered manufacturing of the advanced nanomaterials, offering fine-tuning of the nanostructures of materials with low cost and high productivity.

Construction of functionalized In-based metal organic framework/BiOCl1−xIx Z-scheme heterojunction for efficient photocatalytic degradation of tetracycline: Performance and mechanism

The environmental implications of antibiotics have drawn widespread attention. Numerous monomer-based bismuth oxide halide catalysts have been extensively studied to remove tetracycline (TC) from aquatic environments. Integrating bismuth oxide halide composites with In-based metal organic framework (NH2-MIL-68(In)) might potentially serve as a novel strategy. By meticulously adjusting Cl and I within the composite bismuth halide oxide (B-x), a suite of purpose built heterojunctions (NMB-x) were synthesized, which were engineered to facilitate the efficient photodegradation of TC in simulated and actual aquatic environments. The incorporation of Z-scheme heterojunctions yielded a significant enhancement in photocatalytic responsiveness and charge carrier separation. Notably, NMB-0.3 demonstrated remarkable TC removal efficiency of 88.52 ± 3.05%, which is 3.74 times of B-0.3 within 90 min. The apparent quantum yield was also increased from 8.97% (B-0.3) to 19.68% (NMB-0.3). The removal of TC from natural water bodies was also assessed. Moreover, the photocatalyst concentration, assessed using response surface method, was found to show influential factors on TC removal. In addition, density functional theory (DFT) simulations were employed to identify vulnerable sites within TC. Intermediates and pathways in the photodegradation of TC have also been inferred. Furthermore, a comprehensive environmental toxicity assessment of representative intermediates demonstrated that these intermediates exhibited significantly reduced environmental toxicity compared to TC. This study provides a new approach to the design strategy of efficient and environmentally friendly MOF-based photocatalysts.

Fabrication of porous and defect-rich BiOI/MWCNTs photocatalyst by Ar plasma-etching for emerging pollutants degradation

Carbon material modification and defect engineering are indispensable for bolstering the photocatalytic effectiveness of bismuth halide oxide (BiOX). In this study, a novel porous and defect-rich Ar-CB-2 photocatalyst was synthesized for emerging pollutants degradation. Leveraging the interfacial coupling effect of multi-walled carbon nanotubes (MWCNTs), we expanded the absorption spectrum of BiOI nanosheets and significantly suppressed the recombination of charge carriers. Introducing defects via Argon (Ar) plasma-etching further bolstered the adsorption efficacy and electron transfer properties of photocatalyst. In comparison to the pristine BiOI and CB-2, the Ar-CB-2 photocatalyst demonstrated superior photodegradation efficiency, with the first-order reaction rates for the photodegradation of tetracycline (TC) and bisphenol A (BPA) increasing by 2.83 and 4.53 times, respectively. Further probe experiments revealed that the steady-state concentrations of ·O2− and 1O2 in the Ar-CB-2/light system were enhanced by a factor of 1.67 and 1.28 compared to CB-2/light system. This result confirmed that the porous and defect-rich structure of Ar-CB-2 inhibited electron-hole recombination and boosted photocatalyst-oxygen interaction, swiftly transforming O2 into active oxygen species, thus accelerating their production. Furthermore, the possible degradation pathways for TC and BPA in the Ar-CB-2/light system were predicted. Overall, these findings offered a groundbreaking approach to the development of highly effective photocatalysts, capable of swiftly breaking down emerging pollutants.

Coupled Cu doping and Z-scheme heterojunction for synergistically enhanced tetracycline photodegradation

Coupled Cu doping and Z-scheme heterojunction for synergistically enhanced tetracycline photodegradation

A critical overview on impact of different nano-catalytic assemblies for photodegradation of tetracycline

Abstract Recently, the removal of tetracycline, a toxic material, from aquatic medium has been a trending subject of research. Several different technologies including adsorption, biological removal method, solvent extraction, coagulation, chemical reduction, photocatalysis and ion exchange method for removal of tetracyclines from wastewater have been reported. However, photocatalysis of tetracyclines (TC) has gained huge interest because of more efficient mineralization of TC into CO2 and water. Several different nanomaterial based photocatalytic assemblies for the removal of tetracyclines have been widely reported for the removal of tetracyclines which have not been critically reviewed in the literature. This study provides an overview of recent progress of classification, synthesis, characterizations, mechanism of inorganic and metal organic framework nanocatalytic assemblies on photocatalysis of tetracyclines in aquatic medium. Additionally, kinetics and factors affecting the photocatalysis of tetracyclines have been discussed briefly. Future perspectives have also been presented for further advancement in this area.

Microwave-assisted synthesis of carbon quantum dots and their integration with TiO2 nanotubes for enhanced photocatalytic degradation

This study demonstrates the successful synthesis of carbon quantum dots (CQDs) using the microwave method. Additionally, the hydrothermal method is employed to synthesize CQDs-decorated TiO2 nanotubes (CQDs@TNT) from CQDs decorated TiO2 (CQDs@TiO2). The CQDs induce the quantum confinement effect, observed by employing fluorescence spectroscopy (FL). The decoration of CQDs also results in a 2.92 eV reduction in the band gap in CQDs@TNT. X-ray photoelectron spectroscopy (XPS) reveals the elemental composition of both CQDs and TiO2, including TiO, CO, Ti-O-C, CC, and CO bonds. XRD spectroscopy confirms a reduction in crystallite size and negative microstrain due to compressive strength. The degradation study demonstrates the remarkable photocatalytic activity and stability of CQDs@TNT in the presence of tetracycline (TC) as the target pollutant under simulated visible light. The time dependence of the photodegradation of TC is also studied, and the system is found to be following pseudo second-order kinetics.

Complete photodegradation of tetracycline induced by surface microenvironment of graphitic carbon nitride/silver phosphate

Silver phosphate (Ag3PO4) is a promising photocatalyst, but the photo-corrosion issue limits an effective and comprehensive photocatalysis degradation of tetracycline (TC). In this work, a unique graphitic carbon nitride-Ag3PO4 (KCN-AP(40 %)) core-shell structure was prepared via a simple chemical sedimentation method. The unique graphitic carbon nitride sheet encloses Ag3PO4 to trap excited electrons from the conduction band position of Ag3PO4, suppressing the reduction of Ag+ and Ag metal deposition on the surface of Ag3PO4. Under visible light irradiation, the optimized KCN-AP(40 %) can photodegrade nearby 100 % of TC within 20 min with a first-order kinetic constant of 0.127 min−1, which is 3.34 and 3.97-folds higher than those of Ag3PO4 and graphitic carbon nitride, respectively. A series of factors that may affect photoactivity of KCN-AP (40 %) including pH, inorganic ions, and organic matter are investigated. In final, the photodegradation mechanisms and intermediates were proposed based on ex-situ HPLC-MS. This work explains the deep decomposition of TC and presents a facile approach for designing and manufacturing Ag3PO4 based nanohybrids.

Bi/BiVO4 tailoring molecular oxygen activation for SPR-promoted photocatalytic contaminant removal

In recent years, photocatalytic technology has been gained widespread attention in contaminants removal due to its green, low-carbon, sustainable properties. Bismuth vanadate (BiVO4) with decahedral shapes has emerged as a promising photocatalyst with unique photoinduced charges directional transfer. In this study, a simple wet chemical reduction method was used to load stable Bi0 nanoparticles in situ on the surface of decahedral BiVO4 to enhance the charges movement for molecular oxygen activation and tetracycline photodegradation. The formed Bi0 nanoparticles induced abundant oxygen vacancy defect states and surface plasmon resonance effects on BiVO4 nanoparticles surface. In aid of the special function of a surface heterojunction, decahedral BiVO4 can be photoexcited to produce more photogenerated carriers, and its separation efficiency is greatly improved, thus enhancing both the oxidative activity and photocatalytic activity. In the photocatalytic degradation process, superoxide radicals (∙O2−) showed the most significant contribution, and singlet oxygen (1O2) played junior role in tetracycline hydrochloride (TC) removal. 1O2 is obtained by ∙O2− and hole energy conversion, and some of it is produced by tetracycline photodecomposition under alkaline conditions. The BBV0.4 photocatalytic system has the best catalytic activity under weakly alkaline conditions, and the synergistic effect of photocatalysis and photodecomposition greatly improves the mineralization rate of TC. The large numbers of ∙O2− and 1O2 reactive oxygen species produced by BBV0.4 activation of oxygen play a crucial role in the photodegradation of TC via demethylation, deoxidation, deamination, ring-opening, and carbonylation to complete mineralization. This work studies in depth the change in the decahedral BiVO4 photocatalytic mechanism caused by the in situ introduce of bismuth metal, providing an efficient and environmentally friendly reference method for the rapid removal of tetracycline hydrochloride under alkaline conditions.

Comparison of different iron oxides for degradation of tetracycline anti-bacterial drug

Abstract Nanomaterials have a wide range of applications including novel biomedical studies are devoted to improving the functionality and effectively of traditional and unmodified systems, both drug carriers and common scaffolds for tissue engineering or advanced hydrogels for wound healing purposes. In this regard, metal oxide nanoparticles show great potential as versatile tools in biomedical science. In particular, iron oxide nanoparticles with different shape and sizes hold outstanding physiochemical characteristics, such as high specific area and structure that make them unique nanomaterials to be used in diverse aspects of medicine and biological systems. The challenges associated with the uncontrolled presence of antibiotics such as tetracycline in the environment have necessitated their removal through different techniques. Tetracycline is hard to degrade in living organisms and can even be converted to more toxic substances. In this article different type of iron oxides were subjected to photo degradation of antibacterial drug Tetracycline under UV light illumination and direct sunlight and the results were promising to degrade the drug within 20 min. The SEM, TEM, EDAX and XRD for the catalyst were characterized to confirm the presence of iron oxide, the size and shape of the particle. The kinetics of photo degradation of tetracycline followed the pseudo-first-order mechanism, proceeding through hydroxyl radicals generated under illumination. Moreover, the photo generated hydrogen peroxide could lead to heterogeneous photocatalytic processes on the surface of iron oxide nanoparticles; additionally generating hydroxyl and hydroperoxyl radicals enables photo degradation of tetracycline.

Harmonizing the cyano-group and Na to enhance selective photocatalytic O2 activation on carbon nitride for refractory pollutant degradation

Manipulating exciton dissociation and charge-carrier transfer processes to selectively generate free radicals of more robust photocatalytic oxidation capacity for mineralizing refractory pollutants remains challenging. Herein, we propose a strategy by simultaneously introducing the cyano-group and Na into graphitic carbon nitride (CN) to obtain CN-Cy-Na, which makes the charge-carrier transfer pathways the dominant process and consequently achieves the selective generation of free radicals. Briefly, the cyano-group intensifies the local charge density of CN, offering a potential well to attract the hole of exciton, which accelerates the exciton dissociation. Meanwhile, the separated electron transfers efficiently under the robust built-in electric field induced by the cyano-group and Na, and eventually accumulates in the heptazine ring of CN for the following O2 reduction due to the reinforced electron sink effect caused by Na. As a result, CN-Cy-Na exhibits 4.42 mmol L-1 h-1 productivity with 97.6% selectivity for free radicals and achieves 82.1% total organic carbon removal efficiency in the tetracycline photodegradation within 6 h. Additionally, CN-Cy-Na also shows outstanding photodegradation efficiency of refractory pollutants, including antibiotics, pesticide plastic additives, and dyes. This work presents an innovative approach to manipulating the exciton effect and enhancing charge-carrier mobility within two-dimensional photocatalysts, opening an avenue for precise control of free radical generation.

Internal electric field promoted NCDs/BiOBr/AgBr Z-scheme heterojunction with rich oxygen vacancies for efficient photocatalytic degradation of tetracycline and reduction of Cr (VI)

It is important to prepare efficient photocatalysts for the degradation of antibiotics and heavy metals. In this study, NCDs/BiOBr/AgBr Z-scheme heterojunction photocatalysts with excellent performance were constructed. NCDs/BiOBr/AgBr form a Z-type heterojunction system with pyrrole nitrogen-doped carbon quantum dots (NCDs) as charge transfer channels. The internal electric field formed in NCDs/BiOBr/AgBr greatly facilitated electron transfer. The more easily broken Bi-O bonds were utilized in the synthesis to introduce rich oxygen vacancies (OVs) into NCDs/BiOBr/AgBr to promote molecular oxygen activation. Meanwhile, silver nanorods were reduced in the synthesis to enhance the photodegradation performance. The photocatalytic degradation of tetracycline (TC) and reduction of Cr (VI) were enhanced by about 4 and 6 times. The factors affecting the removal effects of TC and Cr (VI) were analyzed. The catalysts were also tested to have good stability and potential for application in real wastewater. The reactive oxygen species (ROS), which play a dominant role in the photodegradation of TC and Cr (VI) by NCDs/BiOBr/AgBr, were tested, and a possible photocatalytic mechanism was proposed.

Synergy of oxygen vacancies, Lewis acid sites, and interfacial chemical bonds on ZnSnO3/AgI for photodegradation of tetracycline

Chemically bonded Z-scheme ZnSnO3/AgI composites rich in oxygen vacancies (OVs) and Lewis acid sites were prepared successfully and showed excellent photocatalytic activities. Especially, ZnAg-2 degraded 96.1% tetracycline under visible light irradiation for 15 min. OVs contributed to Lewis acid sites production and interfacial chemical bonds formation through weakening the metal−O bonding. Lewis acid sites favored the adsorption of electron-rich tetracycline. Interfacial chemical bonds together with Z-scheme structure accelerated electron transfer and retained the high redox ability of ZnSnO3 and AgI. OVs contributed to singlet oxygen (1O2) production through facilitating the energy transfer from triplet exciton to O2. ZnSnO3/AgI composites possess good reusability and show great practical application potential. Based on ROSs generation and photoreduction experiment, the photocatalytic mechanism of the ZnAg composites was proposed. The possible degradation pathway was deduced and the biological toxicity was evaluated based on detected degradation intermediates. This work highlights the significant roles of OVs, Lewis acid sites, and chemical bonding in improving the photocatalytic activity of Z-scheme composites and provides new insight into designing high efficient photocatalysts.

A review on recent advances in photodegradation of tetracycline in aqueous media

A review on recent advances in photodegradation of tetracycline in aqueous media

A novel Cr2O3/Cr-doped g-C3N4 photocatalyst with a narrowed band gap for efficient photodegradation of tetracycline

Two significant strategies for enhancing photocatalyst performance are heterojunction construction and band gap modulation, but up until now, these methods have typically been treated separately. This work examines a strategy combining the heterojunction with a mid-gap state to prepare a novel Cr2O3 modified Cr-doped g-C3N4 photocatalyst for antibiotics degradation. According to the characterization results, the integration of Cr 3d orbital energy level into the original band gap of g-C3N4 results in the formation of Cr-doped g-C3N4, leading to a reduction in the band gap from 2.80 eV to 2.36 eV. Besides, the constructed Z-type heterojunction enhances the separation of photoinduced carriers. The degradation experiments of tetracycline proved the significant enhancement in the photocatalytic performance of the prepared catalyst. In addition, the degradation effect of the prepared catalyst on tetracycline in micro-polluted lake water was also investigated, revealing the applicability of the catalyst in the purification of natural water environments.

Oxygen vacancy-rich cuprous oxide microspheres exhibit strong absorption and high oxidative energy level for deep photodegradation of tetracycline

In this study, a Cu2O microsphere (WY1) was hydrothermal synthesized by employing a CTAB-cocoylsarcosine sodium composite micellar. WY1 has an unifirm hollow spherical structure formed by agglomeration of nanoparticles, and the results of X-ray photoelectron spectroscopy and electron paramagnetic resonance indicate that WY1 contains significantly increased oxygen vacancies. The degradation efficiency of WY1 for 40 mg L−1 TC reached 93.26% after 60 min visible-light irradiation, which was 2.04 times higher than that of the product prepared without soft template (WNT). Especially, 81.67% residual rate of total organic carbon in the degradation of TC over WY1 was 17.83 times higher than that of WNT (4.58%). The spectral and electrochemical data reveal that the position of valence band of WY1 was exceeded the H2O/·OH potential, and the ·OH species rarely played a key role in the photocatalytic degradation of tetracycline by cuprous oxide. In addition, the ·O2− species were generated by forming the electron transfer pathway with aid of oxygen vacancy-mediated trap, acting as another major active species, which followed a deep photodegradation mechanism of hydroxyl and superoxide radicals dual activities. The spatial agglomeration of cuprous oxide nanoparticles provides a new process for enhancing interfacial energy levels and inhibiting photocorrosion, which cater the antibiotic remediation.

CdS Nanoparticles Supported on a Dual Metal–Organic Framework as a Catalyst for the Photodegradation of Tetracycline

CdS Nanoparticles Supported on a Dual Metal–Organic Framework as a Catalyst for the Photodegradation of Tetracycline

Electronic and photocatalytic properties of N, V co-doped anatase TiO2

Photocatalytic technology has good stability and ecological friendliness which is used to treat organic pollutants in wastewater. In this paper, TiO2, 1.5%V–TiO2 and N, V co-doped TiO2 were synthesized by hydrothermal method for photocatalytic degradation of tetracycline. Meanwhile, XRD, HRTEM, SEM, FT-IR, XPS, UV–Vis DRS, PL and electrochemistry tests were used to characterize the catalysts. The results showed that the appropriate amount of N, V co-doped can cause structural changes of TiO2. The co-doped of N and V enhanced the photocurrent response of TiO2, increased the specific surface area, reduced the band gap, and improved the efficiency of photodegradation of tetracycline. Accordingly, the tetracycline photocatalytic degradation path was proposed. 6%N-1.5%V–TiO2 completely degraded tetracycline into CO2, H2O and NO3−. The calculation results show that an appropriate amount of N, V co-doped TiO2 decreased bandgap, improved the optical absorption performance of TiO2. This work demonstrated the potential of N, V co-doped to design efficient photocatalysts.