Photocatalytic Degradation Of Tetracycline Hydrochloride Research Articles

Photocatalytic degradation of tetracycline hydrochloride and oxytetracycline using novel zinc-based coordination polymers constructed with mixed linkers

In the present work, a new zinc-based coordination polymer was successfully synthesized by mixed-ligand method with the molecular formula of {[Zn(ipa)(Hpap)]·2H2O}n, (abbreviated as Zn-CP), where ipa = isophthalic acid, pap = 4-(1H-pyrazol-4-yl)pyridine. Furthermore, reasonable characterization of Zn-CP was carried out by single crystal X-ray diffraction (SC-XRD), powder X-ray diffraction (PXRD), thermogravimetric analysis (TGA) and other spectra. During the characterization process, it was found that Zn-CP can have excellent acid-base stability, water stability and thermal stability. In addition, the complex was able to effectively degrade tetracycline hydrochloride (TCH) and oxytetracycline (OTC) within 60 min under visible light irradiation (with degradation efficiencies of 80.2 % and 83.5 %, respectively), and the cycling experiments showed that Zn-CP could still effectively degrade TCH and OTC after three cycles. Finally, in order to propose a rational photocatalytic degradation mechanism, free radical trapping experiments and energy band structure analysis were also carried out

Direct Z-scheme CeO2/TiO2 heterojunction derived from tobacco leaf vein biotemplate for visible-light photocatalytic degradation of tetracycline hydrochloride

The development of visible-light-responsive biotemplated TiO2-based photocatalysts has been receiving much attention due to the pressing issue of antibiotic-residues in wastewater. In this work, tobacco leaf veins were utilized as a biotemplate to fabricate Z-scheme CeO2/TiO2 (GTS-CeO2/TiO2) photocatalysts via a solvothermal process followed by in situ calcination. Moreover, the microstructure units of the biotemplate-shaped photocatalysts can be regulated as required. Characterization and photocatalytic test results indicate that the biotemplated CeO2/TiO2 composites feature tight heterojunctions, which can effectively accelerate the separation and migration of photogenerated carriers for the degradation of tetracycline hydrochloride. The photodegradation efficiency of 20 ppm tetracycline hydrochloride under visible-light irradiation reaches 98.9 % over the GTS-CeO2/TiO2 in 120 min, with an apparent rate constant (Kappt) that is 2.9 times higher than that of CeO2/TiO2 synthesized without biotemplating. The enhanced photocatalytic performance is attributed to the construction of Z-scheme CeO2/TiO2 heterojunction, the presence of Ce4+/Ce3+, the unique morphology derived from the biotemplate, and the designed microstructure unit of the photocatalyst. The GTS-CeO2/TiO2 exhibits good stability and can be reused several times. The degradation pathways of TCH were primarily dominated by h+, ⋅OH, and ⋅O2-, leading to a reduction in the toxicity of intermediates. The degradation mechanism of tetracycline hydrochloride was also analyzed and proposed. This work provides a new inspiration for the preparation of visible-light photocatalysts to purify the environment in a more sustainable and environmentally friendly manner.

Effective degradation of tetracycline under visible light by microwave-assisted reflux synthesis of ZnO/MoS2/rGO ternary nanocomposites

ZnO@MoS2 and conducting rGO based ternary nanocomposites were synthesized by a bottom-up microwave-assisted reflux method and effectively investigated for the photocatalytic degradation of tetracycline hydrochloride (TCH) antibiotic. The XRD, EDAX and XPS results corroborates the formation of nanostructure composite with high phase purity. The ZnO nanorods are well grafted on the curled configuration of layered MoS2 and thin surfaced rGO sheets as visualised from HR-TEM analysis. Upon addition of rGO, there is a significant decrease in the bandgap and improved visible light response in the ternary nanocomposites is elucidated by UV–visible Diffuse Reflectance Spectroscopy (UV-DRS) analysis. The suppression in photo-induced electron/hole pair recombination and allowing easy charge transport of ZnMG-50 were evidenced from photoluminescence (PL) and photo-electrochemical impedance (photo-EIS) spectroscopy. From BET and BJH analysis, the enhancement in surface area and pore volume by loading of rGO (SBET = 264.794 m2/g and 0.548 cm3/g). The optimized ZnMG-50 nano-photocatalyst possess a superior photocatalytic performance with higher removal efficiency of 92.18 % was achieved at pH level 10, catalyst dosage 40 mg and TCH concentration 20 ppm within 180 min under illumination. The degradation process compiles a pseudo-first order reaction with a kinetic rate constant of 0.01365 min−1. The nonstop generation of hydroxyl (˙OH) and superoxide (O2˙-) reactive species were beneficial for free electrons in the active participation, which remains as a core factor in the degradation process. The detailed study on ZnMG-50 nanocomposite substantiated to be an efficient noble metal-free synthetic catalyst for enhanced photocatalytic degradation of antibiotics.

Yb-doped BiOBr for highly efficient photocatalytic degradation of tetracycline hydrochloride under visible light irradiation

Bismuth oxybromide (BiOBr) is a common photocatalyst for degrading organic pollutants. Due to its low charge separation efficiency and narrow band gap, it is difficult to achieve good results in practical applications. By doping ytterbium ions (Yb3+) into BiOBr, its absorption and utilization of visible light can be improved, thereby enhancing the photocatalytic performance. In this study, a simple one-step hydrothermal method was used to prepare Yb-doped BiOBr photocatalysts with enhanced oxygen vacancies (OVs). Yb0.4/BiOBr excites molecular oxygen and has a low band gap and a high charge separation efficiency. When tetracycline hydrochloride (TCH) is used for photocatalysis, the degradation efficiency can reach 89.38% within 100 min, and the reaction rate constant is 1.47 times that of BiOBr without Yb doping. Finally, the possible degradation pathways and intermediates of TCH were investigated by liquid chromatography–mass spectrometry (LC–MS). This study provides a new approach for improving the photocatalytic activity of BiOBr.

Ce-Doped Nanosheet as Visible Light Photocatalyst for the Photocatalytic Degradation of Tetracycline Hydrochloride

Ce-Doped Nanosheet as Visible Light Photocatalyst for the Photocatalytic Degradation of Tetracycline Hydrochloride

Conical porous hollow g-C3N4 charge separation with high efficiency for enhancing visible-light photocatalytic activity

The performance of the photocatalysts is influenced by factors such as electron generation ability, charge separation rate, and active sites distribution. In this study, needle-shaped precursors were prepared through low-temperature supramolecular self-assembly, and conical porous hollow carbon nitride (PHCN) was obtained after high-temperature pyrolysis. The PHCN not only possesses a thin-walled porous structure but also contains nitrogen defects embedded in its structure, which synergistically enhance the efficiency of photogenerated charge separation and provide more reactive sites. The DFT calculations showed that nitrogen defects and Pt-loading synergistically optimize the intermediate reaction process of graphitic carbon nitride (g-C3N4). PHCN had excellent photocatalytic degradation of tetracycline hydrochloride (TCH) and Rhodamine B (Rh B). The photocatalytic hydrogen evolution rate of PHCN was 20.0 times higher than that of bulk g-C3N4 (BCN). This study elucidated the relationship between crystallization rate and precursor morphology, as well as the influence of their physicochemical properties on photocatalytic performance. It also lays the foundation for constructing materials with nitrogen defects and special morphology through supramolecular self-assembly.

Direct Z-scheme charge transfer Bi2O3/UiO-66-NH2 heterojunctions for boosted photocatalytic degradation of tetracycline hydrochloride in different water systems

The development of hybrid heterostructure photocatalysts with enhanced visible light absorption capacity holds significant importance in environmental remediation. However, the challenge persists in exploiting strong visible-light responsive photocatalysts with both high efficiency and stability. Herein, we successfully synthesized a hybrid Z-scheme heterojunction of Bi2O3 and UiO-66-NH2 (Bi2O3/UiO-66-NH2) through a simple hydrothermal route. The visible light photocatalytic performance of Z-scheme Bi2O3/UiO-66-NH2 heterojunction is systematically evaluated for persistent antibiotic tetracycline hydrochloride (TC-HCl) both in the clean and real water matrix. All heterojunction catalysts exhibit superior photodegradation capabilities compared to pristine Bi2O3 and UiO-66-NH2. The optimal ratio of the two components heterojunction (BUN-150), in particular, demonstrates the highest removal efficiencies for TC-HCl (95 %) within a 90-min timeframe. This remarkable photocatalytic performance is credited to the Z-scheme charge transfer occurring at the interface of Bi2O3 and UiO-66-NH2 in Bi2O3/UiO-66-NH2 heterojunction. The active species experiments and electron paramagnetic resonance analyses are conducted to identify the active reactive species during the TC-HCl degradation (·OH, h+, and ·O2−), and a precise photocatalytic degradation mechanism is explained. Additionally, the photodegradation intermediates of TC-HCl are detected using the HPLC-MS analysis to explain the degradation pathways of TC-HCl. This research paves the way for the development of novel Z-scheme Bi2O3-based heterojunction catalysts for outstanding photocatalytic applications.

Construction of AgI/PCN-224 Z-scheme heterojunction for efficient photocatalytic degradation of tetracycline hydrochloride: Pathways, mechanism and theoretical calculations

The construction of heterojunction structures is pivotal in enhancing carrier separation and photocatalytic activity. Hence, AgI/PCN-224 (APN-x composites) Z-scheme heterojunctions were successfully synthesised using an in-situ precipitation method. The direction of electron migration and the band structures of APN-x were comprehensively investigated using a combination of experimental approaches and density functional theory (DFT) calculations. Owing to the extensive visible-light absorption capabilities of PCN-224 and the high efficiency of photogenerated carrier separation in the Z-scheme heterojunction, the optimally developed APN-3 photocatalyst demonstrated exceptional photodegradation efficiency for tetracycline hydrochloride (TCH). The removal rate of TCH by APN-3 within 120 min reached 91.56%, approximately 4.64 times higher than that achieved by pure AgI. The photocatalytic degradation mechanism was explored using free radical trapping experiments, electron spin resonance (ESR) technology and band structure analysis. Degradation pathways and intermediate products were investigated using liquid chromatography–tandem mass spectrometry (LC–MS).

Construction of Zn0.5Cd0.5S/Bi4O5Br2 Heterojunction for Enhanced Photocatalytic Degradation of Tetracycline Hydrochloride

The development of efficient catalysts with visible light response for the removal of pollutants in an aqueous environment has been a hotspot in the field of photocatalysis research. A Zn0.5Cd0.5S (ZCS) nanoparticle/Bi4O5Br2 ultra-thin nanosheet heterojunction was constructed by ultrasound-assisted solvothermal method. The morphology, structure, and optoelectronic properties of the composite were characterized by scanning electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy, and UV–vis diffuse reflectance spectra. Under simulated visible light illumination, the photocatalytic performance was evaluated through degradation of tetracycline hydrochloride. Results show that the degradation effect by the optimum ZCS/Bi4O5Br2 catalyst is superior to pure materials with the kinetic constant that is 1.7 and 9.6 times higher than those of Bi4O5Br2 and ZCS, and also has better stability and reusability. Trapping experiments and electron paramagnetic resonance tests find that free radicals in the photocatalytic system are superoxide radicals and holes. This work provides a referable idea for the development of more efficient and recyclable photocatalysts.

Design of magnetically separable double Z-scheme Ag3PO4/Fe3O4/MoS2 heterojunction with enhanced photocatalytic degradation of antibiotics under visible light irradiation

Photocatalysis is a promising technology in treating antibiotic wastewater. However, the rapid recombination of photogenerated electron-hole pairs and the loss of photocatalysts make its practical application challenging. To address these issues, a double Z-scheme heterojunction of magnetically separable Ag3PO4/Fe3O4/MoS2 photocatalyst is designed and applied for the photocatalytic degradation of tetracycline hydrochloride (TCH). The degradation efficiency of TCH by Ag3PO4/Fe3O4/MoS2 can achieve 99.0 % within 7.5 min under visible light irradiation, which is still above 91.3 % after 7 cycles. The excellent photocatalytic performance is attributed to the enhanced carrier life by constructing the double Z-scheme heterostructure in Ag3PO4/Fe3O4/MoS2. Mechanistic study indicates that •O2−, •OH, and h+ radicals are generated during the photocatalytic degradation. Combining experimental and theoretical calculations, two main degradation pathways are proposed, and the toxicity of the degradation system is significantly reduced. This study provides fresh insights into the photocatalytic degradation of refractory antibiotics by constructing magnetically separable Ag3PO4/Fe3O4/MoS2 heterojunction.

A novel La2MnTiO6 perovskite for photocatalytic degradation of tetracycline hydrochloride

One of the majority of environmental pollution is caused by organic substances resulting from anthropogenic and industrial activities, such as dyes, antibiotics, and similar substances. Due to these pollutants’ strong stability, they are difficult to decompose, and their breakdown can only occur slowly through chemical or biological processes. Photocatalysis is a potential method for environmental clean-up with a significant oxidation capacity and a rapid response rate. Among them, double perovskite is an emerging alternative to single perovskite, which has recently shown comparable or even better performance for degrading organic pollutants. The first report on the synthesis of La2MnTiO6 (LMTO) double perovskite for tetracycline hydrochloride (TC) degradation was made in this work. By using XRD, FE-SEM, BET, and EDX analysis, the crystalline structure morphology, and elemental composition of the samples were identified. According to the calcination temperature, only at temperatures greater than 700 °C could the LMTO material be successfully formed. The photocatalytic performances of the prepared samples were evaluated by degrading TC under a UV LED lamp at 365 nm. The 800 °C calcined sample exhibited the highest TC degradation performance, reaching around 62% in 120 min. Besides, the LMTO might eliminate another medicine such as Ciprofloxacin (CIP). Overall, these results offer a potential strategy for employing LMTO photocatalysts to remove various antibiotics.

Efficient photocatalytic degradation of tetracycline hydrochloride by Cu2O/BiVO4 p-n heterostructure

Efficient photocatalytic degradation of tetracycline hydrochloride by Cu2O/BiVO4 p-n heterostructure

Photocatalytic Degradation of Tetracycline Hydrochloride Based on the Structure-Property Exploration of BiOCl.

The correlation between structure and properties in the photodegradation reaction of bismuth oxychloride (BiOCl) was explored in this work. Three BiOCl samples with different sizes, morphological structures, and defects were prepared through a hydrothermal method with experimental manipulation. Their structural properties were comprehensively characterized using X-ray diffraction, scanning electron microscopy, transmission electron microscopy, electron spin resonance, X-ray photoelectron spectroscopy, Fourier transform infrared spectroscopy, ultraviolet-visible diffuse reflectance spectroscopy, and photoluminescence. Taking the photodegradation of tetracycline hydrochloride (TC-HCl) as the probe reaction, we found that high activity could be achieved by decreasing their crystal size and thickness, introducing proper defects in the structure, and assembling the nanosheets to get microball structure. Combined with radical-scavenge experiments and electron spin resonance (ESR) spin-trap spectra, we conclude that ̇O2- was the dominant reactive oxygen species for the degradation reaction. The degradation detailed pathway of TC-HCl was further analyzed using liquid chromatography-mass spectrometry. This work explores the structure-property correlation of BiOCl and provides strategies for the rational design of active photocatalysts for water remediation.

Constructing a Titanium Silicon Molecular Sieve-Based Z-Scheme Heterojunction with Enhanced Photocatalytic Activity.

Titanium silicon molecular sieve (TS-1) is an oxidation catalyst that possesses a long lifetime of charge transfer excited state, high Ti utilization efficiency, large specific surface area, and good adsorption property; therefore, TS-1 acts as a Ti-based photocatalyst candidate. In this work, TS-1 coupled Bi2MoO6 (TS-1/BMO) photocatalysts were fabricated via a facile hydrothermal route. Interestingly, the optimized TS-1/BMO-1.0 catalyst exhibited a decent photodegradation property toward tetracycline hydrochloride (85.49% in 120 min) under the irradiation of full spectrum light, which were 4.38 and 1.76 times compared to TS-1 and BMO, respectively. The enhanced photodegradation property of the TS-1/BMO-1.0 catalyst could be attributed to the reinforced light-harvesting capacity of the photocatalyst, high charge mobility, and suitable band structure for tetracycline hydrochloride degradation. In addition, the mechanism of photocatalytic degradation of tetracycline hydrochloride by the TS-1/BMO-1.0 catalyst was reasonably proposed based on the band structure, trapping, and ESR tests. This research provided feasible ideas for the design and construction of high-efficiency photocatalysts for contaminant degradation.

Harnessing intrinsic defect complexes for visible-light-driven photocatalytic activity in Delafossite CuAlO2

This study significantly enhances the photo(electro)catalytic capabilities of CuAlO2, a wide bandgap semiconductor, through targeted defect engineering. By employing a tailored solid-state reaction under a mixed oxygen-argon atmosphere, an intrinsic defect complex of [Oi+CuAl] into has been successfully integrated into CuAlO2, thereby expanding its light absorption to the visible spectrum. The optimized CuAlO2 sample, containing the [Oi+CuAl] complex, demonstrates a remarkable 2.13-fold increase in photocatalytic degradation of tetracycline hydrochloride under visible-light irradiation. The maximum incident photon-to-current conversion efficiency value is elevated from 0 to 3.27 %, and the photocatalytic water splitting hydrogen production rate is increased by 10.78-fold. Density functional theory calculations, in conjunction with experimental data, elucidate the role of the [Oi+CuAl] complex in facilitating visible-light absorption and improving the separation of photogenerated electron-hole pairs. Under simulated sunlight, the modified CuAlO2 sample exhibits a substantial 2.26-fold enhancement in photocatalytic degradation of tetracycline hydrochloride, a photocurrent density increase from 0.80 to 8.20 µA·cm−2, and a 1.13-fold increase in photocatalytic hydrogen production rate compared to defect-free CuAlO2. This research underscores the potential of strategic defect engineering to enhance visible-light-driven photo(electro)catalysis in wide bandgap semiconductors.

Convenient interface engineering of hierarchical flower spherical Bi-MOF/Bi2WO6 heterostructures for high-performance visible light photocatalytic degradation of tetracycline hydrochloride

Convenient interface engineering of hierarchical flower spherical Bi-MOF/Bi2WO6 heterostructures for high-performance visible light photocatalytic degradation of tetracycline hydrochloride

Enhanced photocatalytic degradation of tetracycline hydrochloride over Cd-CdS@g-C3N4 under visible light irradiation

Cadmium sulfide (CdS), known for its strong light absorption capability and narrow band gap, has been extensively employed in photocatalytic degradation of organic pollution. However, when be exposed to light, the surface lattice sulfur of CdS undergoes rapid oxidation due to photo-generated holes, resulting in significant photocorrosion. Therefore, enhancing the stability and suppressing the photocorrosion of catalyst are crucial. In this study, Cd metal-loaded Cd-CdS@g-C3N4 composite catalysts are developed. This design not only effectively mitigates the issue of CdS photocorrosion but also exhibits outstanding photocatalytic degradation performance. XRD analysis reveals that Cd-CdS exhibits stronger diffraction peaks compared to CdS, indicating enhanced crystallinity and catalyst stability. Utilizing Cd as a metallic mediator, a rapid charge transfer across the heterojunctions is facilitated, bestowing the catalyst with superior photocatalytic efficiency. Notably, Cd-CdS exhibited the best photocatalytic degradation performance when the mass ratio of Cd-CdS to g-C3N4 was 1:2. The composite catalytic degradation efficiency of tetracycline hydrochloride (20 g·L-1) by Cd-CdS@g-C3N4 after 20 minutes reached 86.3%, and this commendable degradation rate was maintained even after four cycles. This research provides a vital approach towards enhancing the stability of g-C3N4/CdS heterojunction photocatalysts.

Bandgap engineering of carbon nitride by formic acid assisted thermal treatment for photocatalytic degradation of tetracycline hydrochloride

Carbon nitride had unique structure and electronic properties, and had wide application prospects in the field of photocatalysis. However, the rapid photogenerated carrier recombination efficiency and low photocatalytic activity limit its use. Defect construction was considered to be an effective strategy to improve the photocatalytic activity of carbon nitride. In this paper, nitrogen defective carbon nitride was prepared by formic acid assisted pyrolysis. The formic acid was used to regulate the top atoms and effectively shorten the band gap. Second, the gas released during pyrolysis contributed to the construction of porous structures. SEM, TEM, BET, XPS were used to confirm the presence of nitrogen defective sites. When it was used to photocatalyze the degradation of tetracycline, the main antibiotic pollutant in Dongting Lake, the degradation rate of 95.1 % was achieved in 60 min. Compared with conventional carbon nitride, the degradation rate constants were 0.04751 min−1 and 0.02110 min−1, respectively. Compared with CN, the degradation rate constant of FCN-5 was increased 2.2 times. The photocatalytic degradation activity was verified by photochemical experiments. •O2– and 1O2 active radicals dominate the photocatalytic degradation process. The ecological safety of Dongting Lake water samples repaired by defective carbon nitride has been confirmed, and the toxicity of antibiotics to the germination and growth of legumes has been effectively alleviated. Five cycles of the experiments ensured that the material can be reused. The above work provided reference and basis for the development and design of defective carbon nitride for water body restoration in Dongting Lake basin.

Synthesis of highly conductive carbon quantum dot-enhanced Z-scheme BiOBr/g-C3N4 heterojunction for effective photocatalytic degradation of tetracycline hydrochloride

BiOBr can effectively mitigate the ecological and environmental problems caused by pollution with antibiotics, and its photocatalytic properties can be improved by utilizing heterojunction structures and cocatalysts. In this study, the Z-scheme heterojunction ternary photocatalyst BiOBr/g-C3N4/CQDs (BCCx) was obtained by using an uncomplicated electrostatic self-assembly process. The incorporation of carbon quantum dots (CQDs) with high conductivity provided a conduit for charge transfer between g-C3N4 and BiOBr. The loading density of CQDs on BiOBr/g-C3N4 could be rapidly adjusted by changing the concentration of the CQDs precursor in solution. The presence of CQDs enhanced the absorption of visible light and inhibited the synthesis of photogenerated charge carriers, thereby resulting in a synergistic effect on the Z-scheme heterojunction and improving the photocatalytic properties under visible light. In particular, BCC50 had the highest catalytic performance, with a tetracycline pollutant degradation efficiency of 100% within 60 min. The degradation efficiency remained above 95% even after repeated use in five cycles. The principles of semiconductor energy bands and internal electrostatic field generation are applied to explain the photocatalytic mechanism responsible for tetracycline degradation using BiOBr/g-C3N4/CQDs.

Photocatalytic degradation of tetracycline hydrochloride using pure and copper-doped magnesium ferrite nanoparticles: Efficiency, kinetics and mechanism

This study presents the synthesis of Mg1-xCuxFe2O4 (x = 0.0, 0.1, 0.3, and 0.5) nanoparticles (NPs) using the direct microwave combustion method (MCM) with L-arginine as the fuel source. The samples were characterised comprehensively using various analytical techniques, including X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), High resolution scanning electron microscopy (HRSEM), Energy-dispersive X-ray (EDX), Diffuse reflectance spectroscopy in the ultraviolet–visible (DRS-UV) range, Fourier-transform infrared spectroscopy (FTIR), and Vibrating sample magnetometry (VSM). The cubic spinel structure was verified by X-ray diffraction analysis. It revealed an average crystallite size ranging from 15.8 to 26.6 nm. The oxidation states and elemental composition of Mg1-xCuxFe2O4 were evaluated using XPS analysis. Notably, the major absorption bands at 557 and 434 cm−1 corresponded to the tetrahedral (Mg2+ –O2−) and octahedral (Fe3+ –O2−) sites, respectively. HRSEM images showed agglomerated particles with elemental verification of Mg1-xCuxFe2O4. This was validated by EDX studies. The optical bandgap was determined by DRS-UV analysis. Functional groups were analyzed by FTIR spectra. Hysteresis loop measurements revealed the ferromagnetic properties of the obtained samples. Furthermore, the study evaluated the detailed mechanism of the photocatalytic degradation (PCD) of Mg0.7Cu0.3Fe2O4.