Degradation Of Tetracycline Hydrochloride Research Articles

Schottky heterojunction-based photocatalysis-in-situ-self-Fenton system: Removal of tetracycline hydrochloride and biotoxicity evaluation of intermediates

Efficiently removing tetracycline hydrochloride (TC) while minimizing the formation of toxic intermediates is a significant challenge. A novel photocatalysis-in-situ-self-Fenton catalyst, RF/EA-Fe@Ti3C2, removed 92 % of TC (20 mg L−1, 100 mL) under visible light irradiation within 80 min. The results of optical thickness and local volumetric rate of photon absorption demonstrated that RF/EA-Fe@Ti3C2 had superior light capture ability than that of RF/EA-Fe. TC significantly inhibited wheat seed germination, seedling growth, and chlorophyll and carotenoid generation, whereas its intermediates had a lesser effect. Additionally, TC damaged the photosystem II (PSII) of wheat seedlings, reducing light response ability and energy capture efficiency, while TC intermediates caused damage similar to deionized water. The rapid TC degradation and low-ecotoxic intermediates stem from the synergistic effects between photogenerated holes and hydroxyl radicals. This study advanced the design of photocatalysis-in-situ-self-Fenton systems for antibiotic degradation and detoxification.

Anchoring highly dispersed FeCo/C nanoparticles within zeolite 13X to promote 1O2 generation in the degradation of tetracycline hydrochloride

This paper reports the preparation of a FeCo/C@13X catalyst derived from FeCo/ZIF using Na-13X molecular sieves as substrates through the ion-exchange method, followed by in situ FeCo/ZIF growth and a carbonization step. Compared with FeCo/ZIF@13X and Co/C@13X, FeCo/C@13X exhibited an improved peroxymonosulfate (PMS) activation effect owing to the well-dispersed FeCo sites embedded in the carbon@13X matrix, as confirmed by high-resolution transmission electron microscopy, Fourier transform infrared spectra and X-ray diffraction. The cobalt loading in the FeCo/C@13X catalysts was up to 15.32 wt% as determined by ICP-OES. FeCo/C@13X, prepared by the introduction of organic Fe and calcining FeCo/ZIF@13X, exhibited good reusability and stability, viz. 92 % degradation efficiency after five cycles compared to 84 % of Co/C@13X and 79 % of FeCo/ZIF@13X. The FeCo/C@13X/PMS system was highly stable over a wide pH range and showed excellent tolerance for background substances in aqueous environments because of non-radical-dominated degradation. Quenching experiments and electron paramagnetic resonance analysis demonstrated that singlet oxygen (1O2) primarily facilitated the tetracycline hydrochloride (TCH) removal during the FeCo/C@13X catalytic process. The electron transfer and free radicals (SO4∙−, ∙OH, and O2∙−) were engaged in the TCH degradation. Through electrochemical measurements and in situ Raman spectroscopy, electrons were rapidly transferred from FeCo/C@13X to PMS, consuming HSO5− to generate metastable active species (FeCo/C@13X-PMS* complexes), which can efficiently accelerate the cycling of Fe3+/Co3+ to Fe2+/Co2+ and enhance 1O2 production. This study provides a suitable method for designing heterogeneous Fenton-like catalysts with high and stable catalytic performances for the continuous production of 1O2.

Activation of peroxymonosulfate by FeOOH modified biochar for the degradation of tetracycline hydrochloride

For preventing environmental pollution and realizing resource utilization of agricultural and forestry wastes, biochar was formed after high temperature pyrolysis of citrus peels under anoxic conditions, and employed as catalyst to activate peroxymonosulfate (PMS) for degrading tetracycline hydrochloride (TC) in wastewater. Furthermore, α-FeOOH modified biochar was fabricated through an alcohol-assisted hydrothemal method for proving the catalytic activity of biochar. The prepared catalysts were characterized by several characterization techniques. Results showed that the catalytic activity of α-FeOOH modified biochar was much better than that of biochar or α-FeOOH, which is attributed to the synergistic effects of biochar and α-FeOOH on the PMS activation. Meanwhile, the effects of PMS concentration, co-existing ions (Cl-, NO3−), and humic acids (HA) on the degradation of TC were investigated through static experiments. More importantly, radical trapping experiment tests suggested that hydroxyl radical (•OH), sulfate radical (SO4•-), and singlet oxygen (1O2) were generated during the process of catalyst activation of PMS, and 1O2 played the main role for TC degradation.

Fe(Ⅲ)-doped ZnIn2S4-modified graphene oxide in-situ for the degradation of tetracycline hydrochloride in simulated sunlight

To improve the efficiency of photocatalytic reactions, it is important to understand how to achieve fast directional migration and separation of photogenerated carriers at the interface. Here, Fe(III)-doped ZnIn2S4 (ZIS)-coated graphene oxide (GO) composite (GZF) was in-situ prepared via the low-temperature water bath method. Ultrathin Fe(III)-doped ZIS nanosheets were uniformly grown upright on the GO surface. The prepared samples were studied via, such as, X-ray diffraction, scanning electron microscopy combined with energy-dispersive spectroscopy, transmission electron microscopy, ultraviolet spectroscopy, N2 adsorption–desorption measurements, X-ray photoelectron spectroscopy, and electron spin resonance. Compared with ZnIn2S4 (ZIS)-coated graphene oxide (GZ), the GZF exhibit a 2.26-fold increase in the photocatalytic degradation performance of tetracycline hydrochloride (TCH) in simulated sunlight. Through density functional theory calculations, found that Fe(III) doping introduces new energy levels into ZIS, which effectively narrow its bandgap and thus enhance its light absorption efficiency. It was found that h+, ·O2−, and 1O2 were the major reactive oxygen species involved in the photocatalysis, and the effect of pH on the catalytic degradation of TCH was examined. Electron spin resonance and density functional theory results indicate that Fe(III) acts as an electron trap in the ZIS structure to promote the separation of photogenerated electron-hole pairs, which in turn enhances the photocatalytic efficiency of GZF-25.

Synthesis and application of Ag3PO4 photocatalyst modified by g-C3N4 for tetracycline hydrochloride degradation

Finding highly efficient photocatalysts has practical significance for antibiotics degradation. In this work, g-C3N4 modified Ag3PO4 had been prepared via in-situ deposition method. Their photocatalytic activities were investigated through tetracycline hydrochloride (TCH) degradation under visible light. In summary, sample 6 wt% g-C3N4/Ag3PO4 (6 wt% CN/APO) exhibited a good degradation efficiency (72.1 %) to TCH within 30 min, while pure Ag3PO4 and g-C3N4 was only 57.4 % and 5.8 %, respectively. Because of the construction of heterojunction structure, 6 wt% CN/APO composite had low fluorescence intensity, high photocurrent density and low resistance, which were helpful for the rapid separation of photogenerated carriers. Therefore, the photocatalytic property of Ag3PO4 was obviously enhanced. In addition, sample 6 wt% CN/APO also showed excellent photocatalytic stability, and h+ played a main role in TCH degradation. Its possible photocatalytic mechanism was also elucidated.

Construction of heterojunctions with in situ growth of ZnIn2S4 nanosheets on the surface of atomically dispersed Cu-modified MOFs for high-performance visible-light photocatalytic antibiotic degradation

Metal-organic frameworks (MOFs) are ideal candidates for obtaining composites with excellent photocatalytic properties due to their reasonable band gaps and high specific surface area. In this study, Cu@UiO-66-NH2@ZnIn2S4 nanocomposites were prepared by a two-step photoinduction method and hydrothermal method. The prepared catalysts in a range of ratios showed high visible light degradation of tetracycline hydrochloride (TC). Among them, 10%-Cu@UIO-66-NH2/ZnIn2S4 showed the best catalytic activity and photoelectrochemical performance. In this catalytic system, the high specific surface area and porosity of UIO-66-NH2 provide sites for the high dispersion of Cu. In addition, the introduction of Cu also reduces the band gap, which is conducive to the electron transfer between the interfaces, which results in the formation of type II heterojunctions with a unique and highly efficient electron transfer mechanism, and also enables the photocatalytic process to generate more active radicals (O2–, OH, h+). In addition, the stability of the catalyst was tested, as well as the possible degradation pathways were hypothesized to evaluate its toxicity. Thus, this study provides a strategy for the preparation of stable and efficient photocatalysts..

One-step preparation of Z-scheme g-C3N4 nanorods/TiO2 microsphere with improved photodegradation of antibiotic residue

Graphitic carbon nitride nanorods/titanium dioxide microspheres (g-C3N4 NRs/TiO2 MSs) Z-scheme heterojunctions were simply prepared by a one-step hydrothermal method, which showed improved visible-light-induced photocatalytic activity for the degradation of tetracycline hydrochloride (TC-HCl). The photodegradation activity of g-C3N4 NRs/TiO2 MSs is 6.6 and 1.9 times better than that of pristine g-C3N4 and TiO2, which is assigned to the unique morphology and formed heterojunction. Hydroxyl radical (⋅OH) and superoxide radical (⋅O2−) were the main species for TC-HCl photodegradation according to capture experiments, and a possible mechanism is proposed. This study provides an effective reference for the preparation of binary heterostructures with excellent photocatalytic activity from a simplified process.

Z-scheme Bi2WO6/KCN heterojunction towards efficient photocatalytic degradation of tetracycline hydrochloride

Antibiotic overuse raises environmental concerns, boosting the demand for efficient removal from pharmaceutical wastewater. Photocatalysis, particularly using semiconductor photocatalysts, offers a promising solution and garners significant scientific interest. In this study, a cyanamide defective carbon nitride (KCN) and Bi2WO6(BWO) heterojunction photocatalyst (2-BWO@KCN) was developed, analyzed, and employed for the photocatalytic degradation of tetracycline hydrochloride (TC) under visible light. The as-synthesized heterojunction 2-BWO@KCN sample demonstrates superior performance compared to pure BWO, CN, KCN, and the heterojunction with pure CN (i.e., 2-BWO@CN) in terms of degrading TC and generating photocurrent under visible light. The study found that the degradation efficiency was affected by the dosage of 2-BWO@KCN and the presence of coexisting ions. Under optimal conditions, the degradation efficiency could reach 87% within 20 min of illumination. Additionally, through comprehensive experimental analysis, the degradation pathway, band structure, and mechanism were thoroughly explored. The superior photocatalytic performance of 2-BWO@KCN was attributed to its Z-scheme heterojunction structure, which significantly reduced the recombination of photogenerated electron and hole (e−/h+) pairs. The radicals (•OH/•O2−) produced were identified using ESR, and their role in tetracycline degradation was further analyzed through active species trapping experiments.

Frustrated Lewis pairs on hollow flower-liked carbon nitride by phosphorous and tungsten co-doping to enhance photocatalytic performance

Frustrated Lewis pairs (FLPs) exhibit a distinctive “push-pull” effect that efficiently triggers the activation of diverse molecules, leading to unforeseen catalytic capabilities. In this study, phosphotungstic acid (PTA) is introduced into graphitic carbon nitride (g-C3N4). Here, phosphorus (P) as the Lewis acid (LA) site, while the electron-rich N-active site neighboring tungsten (W) assumes the role of the Lewis base (LB) site, giving g-C3N4 a FLPs-like property. The formation of FLPs creates a robust “pull-push” effect, thereby improving the separation of photogenerated carriers. This prepared CNW-20 sample demonstrates effective photocatalytic capabilities for hydrogen (H2) evolution and for degrading organic pollutants. Production levels of H2 reached up to 1044.36 μmol h−1·g−1, surpassing the bulk g-C3N4 by a factor of 14. Concurrently, the efficiency of CNW-20 sample in degrading tetracycline hydrochloride (TC) reached 83.40 %. This study introduces a novel approach for the systematic design of FLP sites on metal-doped photocatalysts, aiming to enhance the efficiency of H2 generation and the degradation of pollutants.

Activation of Peroxodisulfate Coupled with Photocatalysis by Pyrrolic N‐Rich Fe‐N4 Sites for High Efficiency Degradation of Tetracycline Hydrochloride

AbstractPhotocatalysis is an efficient technology for the degradation of pollutants. However, there is still much room for improvement in its degradation efficiency. In this study, a pyrrolic N‐rich g‐C3N4 (PN‐g‐C3N4) framework was synthesized with transition metal M (M=Fe, Co, Ni, Cu, Cr, and Mn) atomic sites coordinated onto it. Then, a series of single atomic metals M anchored to PN‐g‐C3N4 (M/PN‐g‐C3N4) are constructed for peroxodisulfate activation. Their order of catalytic activity follows Fe>Cr>Ni>Cu≈Co>Mn, in particular the degradation rates of the TCH for Fe‐PN‐g‐C3N4 are 3.74 times higher than that of undoped PN‐g‐C3N4. These carefully regulated pyrrolic N‐rich Fe sites demonstrate outstanding performance in degrading organic pollutant. As an exemplary model, the Fe/PN‐g‐C3N4 catalyst efficiently drives the catalytic oxidation of TCH through Fenton‐like reaction under visible light, showcasing exceptional cycle stability and a broad effective pH range of 3.0–11.0. The synergy between photocatalysis and Fe doped catalysis results in increased generation and separation of charge carriers, along with the cyclic transformation of the Fe3+/Fe2+ couple. This combination significantly enhances the Fenton‐like performance, making it a highly effective process for pollutant degradation.

One-step high-efficiency microwave synthesis of N-doped bamboo biochar for tetracycline degradation

N-doped bamboo biochar (NBB) was successfully synthesized through one-step, rapid pyrolysis (e.g., 10 min) using urea and urea nitrate impregnated bamboo particles exposed to low power (e.g., 460 W) microwave radiation. NBB-460 exhibited high specific surface area of 876.1 m2/g and outstanding catalytic performance for tetracycline hydrochloride (TCH) degradation. The TCH degradation efficiency reached to 94.3 % with the optimized catalytic condition (i.e., 0.2 g/L NBB-460, 3 mM PMS, 50 mg/L TCH, 25 ℃, without pH regulation). The density functional theory calculation showed that the graphitic nitrogen and pyridinic nitrogen of NBB-460 served as active sites for peroxymonosulfate activation and TCH degradation. The quenching test, electron paramagnetic resonance spectra, and electrochemical measurements indicated that tetracycline hydrochloride underwent degradation via radical (O2•−), non-radical (1O2) pathways, and surface electron transfer. This study introduces an energy-efficient and time-effective method for converting biomass to N-doped biochar as highly efficient peroxymonosulfate activator for environmental applications.

Enhanced Photocatalytic Degradation by the Preparation of a Stable La-Doped FeTiO3 Photocatalyst: Experimental and DFT Study.

The rapid photocarrier recombination limits the photocatalytic activity of iron titanate (FeTiO3) to be further improved. Developing novel approaches to inhibit the rapid recombination rate of the FeTiO3 photocatalysts is crucial for efficiently degrading pollutants in wastewater. Rare earth ions, with unique electron dispositions and large ion radii, could effectively inhibit photocarrier recombination. Herein, novel lanthanum (La)-doped FeTiO3 photocatalysts were designed and successfully synthesized. The photocatalytic performance of the 12 mol % La/FeTiO3 photocatalyst was superior in degrading tetracycline hydrochloride (TCH), methylene blue (MB), and brilliant blue (BB). These degradation rate constants (k) were 0.12358, 0.01357, and 0.03064 L mg-1 min-1, respectively, which were 12.83, 1.61, and 7.78 times that of pure FeTiO3. The photoelectronic tests and density functional theory (DFT) calculations revealed that the La 4f orbital forms an impurity energy level in the conduction band of FeTiO3. This level narrows the bandgap and acts as an electron acceptor, capturing photoexcited electrons and inhibiting the rapid recombination of photoexcited electron-hole pairs in FeTiO3. This work enhances the potential of FeTiO3 in the photocatalysis field and provides important insights into the efficient degradation of organic pollutants in wastewater.

(Mn, Co, Cu)-Ce solid solution for efficient degradation of tetracycline via photo-fenton-like process

Herein, (Mn, Co, Cu)-Ce solid solution (MnCeOx, CoCeOx and CuCeOx) catalysts were successfully synthesized and applied in a Photo-Fenton-like system for tetracycline hydrochloride (TCH) degradation. The CuCeOx/H2O2 system displayed the best catalytic activity compared with CoCeOx/H2O2 and MnCeOx/H2O2 systems under visible light irradiation. The high TCH degradation performance of CuCeOx/H2O2 system was mainly ascribed to the synergistic effect of photocatalysis and Fenton-like reaction, which accelerated the cycle between Cu2+ and Cu+ by using the photoinduced carriers and facilitated the generation of reactive radicals. Furthermore, the possible mechanism of MnCeOx, CoCeOx and CuCeOx photocatalysts activating H2O2 toward TCH degradation was proposed.

Self-assembled iron (II) phthalocyanine modified oxygen vacancy-rich WO3 nanofibers with unique S-scheme heterojunctions for efficient tetracycline hydrochloride degradation and CO2 reduction

The advancement of efficient photocatalysts is crucial for the conversion of carbon dioxide (CO2) into chemical fuels and wastewater treatment, due to the significant role in promoting energy sustainability and environmental remediation. In this work, we synthesized iron (II) phthalocyanine modified oxygen vacancy-rich (FePc/OVs-rich WO3) photocatalyst with an S-scheme structure through electrospinning-calcination and electrostatic self-assembly. The optimized FePc/WO3–2 nanocomposite demonstrated approximately 3.69-fold enhancement in photoactivity for the conversion of CO2 to CO and CH4, as compared with the OVs-rich WO3 nanofibers. Furthermore, the FePc/WO3–2 catalyst demonstrated outstanding efficacy in activating peroxymonosulfate (PMS) for the degradation of tetracycline hydrochloride (TC), achieving an efficiency of 84.9 % within 60 min and a rate constant of 0.924 h−1. The improved photocatalytic performance is attributed to the prolonged absorption of visible light, enhanced charge separation and the increased density of catalytic reaction sites. The enhancement in charge separation is predominantly linked to the unique S-scheme transfer process, which is characterized by non-overlapping optical absorption, in-situ X-ray photoelectron spectroscopy (XPS) and density functional theory (DFT). This process is further facilitated by the catalytic activity of central Fe2+ in FePc for the degradation of TC. The π-π interaction between FePc and the WO3 nanofibers, which have a high concentration of oxygen vacancies, resulted in a fast electron transfer pathway, allowing efficient transport of photoelectrons. This paper comprehensively examines the advancement of high-performance S-scheme FePc/OVs-rich WO3 photocatalysts for the photocatalytic reduction of CO2 and degradation of tetracycline through the photo-assisted activation of PMS.

Ti-doped synergistic hollow thin-walled Bi2O3 nano-microspheres for efficient tetracycline hydrochloride photodegradation

Bismuth oxide (Bi2O3) has been extensively investigated in the fields of environmental photocatalysis, owing to its exceptional charge transport performance and remarkable resistance to photocorrosion. However, the limited absorption spectrum of light and rapid recombination of photogenerated charge results in a low quantum efficiency. Herein, an efficient photocatalytic system for tetracycline hydrochloride (TCH) photodegradation based on titanium (Ti)-doped hollow, thin-walled Bi2O3 with nano-microspheres is fabricated via a facile self-assembly strategy. It is shown that doping Ti in Bi2O3 can generate oxygen vacancies, in addition, the addition of Ti in the solvothermal process inhibits the conversion of Bi3+ to bismuth at high temperature, making the content of each component in the heterostructure controllable. The hybrid catalyst exhibits superior performance in visible-light-driven photocatalytic degradation of TCH (about 95.1 % degradation efficiency after 120 min) and excellent stability (up to 4 cycles) under visible light irradiation. The optimized catalyst exhibits excellent performance in visible light catalytic degradation, owing to the synergistic effect of high specific surface area, Bi plasma resonance effect and charge mobility. Moreover, the photocatalytic mechanism of Ti-Bi2O3 have been deeply analyzed through experimental investigation and DFT theoretical calculations. The findings contribute to the synthesis of efficient visible-light-driven Bi-based photocatalysts and to the understanding of photocatalytic degradation reactions.

Synthesis of heterojunction BiVO4/MnO2 graphene ternary nanocomposites with enhanced photocatalytic activities through degradation of rhodamine B and tetracycline hydrochloride

Our research has resulted in synthesizing highly efficient BiVO4/MnO2 graphene ternary heterostructures prepared with a simple hydrothermal technique. These structures demonstrate exceptional performance in the photodegradation of rhodamine B (RhB) dye and tetracycline hydrochloride (TC). Adding MnO2 and graphene oxide significantly enhanced the absorption of visible light, photocatalytic activity, and surface area of the nanocatalyst. The prepared materials were characterized by XRD, SEM, BET, DRS, and PL spectroscopy. The PL spectra of G/MnBV-4 show less intensity and lower recombination rate, which is beneficial for photocatalytic activity. The as-synthesized G/MnBV-4 material exhibits outstanding photocatalytic activities toward the TC and RhB dye degradation under visible light irradiation. The reaction rate constant of G/MnBV-4 was estimated in the case of RhB and TC as 0.094 min−1 and 0.021 min−1 respectively, showcasing the material's high efficiency. The optimized material (BiVO4/MnO2 graphene) is stable and reusable, with only a 10 % reduction in removal efficiency after five consecutive cycles. Furthermore, the OH− and O2− are active species for removing organic pollutants. In contrast, holes are attributed to a lower effect. This study describes a photocatalytic approach to effectively removing the TC from waste bodies. The enhanced degradation efficiencies were ascribed to developing heterostructures and fast electron transfer between interfaces. Moreover, graphene increased photogenerated charge carriers' surface adsorption properties and charge separation efficiency. Hence, graphene works as an electron trapper and tuning bandgap energy, which plays a significant role in addition to photocatalytic activity.

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, Hpap = 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.

Enhanced visible light utilization of BiOI/BiOBr/Bi composite catalytic materials for photocatalytic degradation of TC and reduction of Cr(Ⅵ)

The rational design and construction of semiconductor photocatalytic materials are important significance for efficient utilization of solar energy and enhancement of photocatalytic activity. In this study, composite photocatalytic materials modified with Bi0 on the surface of BiOI/BiOBr heterojunction were successfully constructed based on the current mature electrostatic spinning technology by using solvothermal and in-situ reduction methods. The successful preparation of BiOI/BiOBr/Bi composites was confirmed by a series of characterization methods. The composite photocatalyst was applied to the degradation of pollutants, and by adjusting the addition ratio of different substances, it was found that the photocatalytic composites prepared with the addition of 0.125 mmol NaBH4 and the ratio of I/Br of 3:1 showed the best performance. The degradation efficiency of the catalyst for tetracycline hydrochloride (TC) at 10 mg/L reached 98.4 % after 180 min of visible light irradiation, and the high degradation performance of the material was maintained after five cycles. Meanwhile, the reduction efficiency of the material for Cr(VI) was 98.2 % after 100 min of visible light irradiation. Free radical trapping experiments demonstrated that photogenerated holes (h+) and superoxide radicals (•O2−) are the main active substances for photocatalytic degradation of TC. Due to the partial reduction of Bi0, the absorption of the catalyst in the near-infrared region was enlarged, which enhanced the photothermal effect of the whole material and further improved the catalyst activity.

Enhanced tetracycline hydrochloride degradation at near neutral conditions with FeOx modified Bi4TaO8Cl catalyst: Coupling the photocatalytic and Fenton oxidation

The efficient regeneration of Fe2+ active sites in heterogeneous catalysts is of great significance for the photo-Fenton progress. Herein, amorphous FeOx as one efficient cocatalyst was anchored on the Bi4TaO8Cl nanosheets to boost the activation of H2O2 and the separation of photogenerated carriers. The surface-exposed FeOx can produce Fe2+ active sites by extracting the photogenerated electrons from Bi4TaO8Cl. As a result, the redox cycle of Fe3+/Fe2+ was built and the carriers were separated to boost the continuous photo-Fenton degradation. As a result, H2O2 are continuously activated through the cycle of Fe3+/Fe2+. The coupling of photocatalysis and the Fenton reaction enhances the TC-H degradation performance and suppress the loss-activation of iron sites. The optimized FeOx/Bi4TaO8Cl sample exhibited the highest degradation ratio of about 83.5 % in 20 min, which was nearly 4 times that of the pure Bi4TaO8Cl. In addition, the better performance of FeOx/Bi4TaO8Cl catalyst under near-neutral conditions also sheds new insights about the design of efficient photo-Fenton catalysts that can work under mild conditions.

ZIF-67/natural coal gangue composite as hydrogen peroxide activator for tetracycline hydrochloride degradation in water

The advanced oxidation process based on hydrogen peroxide (H2O2) can effectively degrade tetracycline hydrochloride (TC). The key to activating H2O2 for the degradation of organic pollutants lies in the exploration of efficient and cost-effective catalysts. Natural coal gangue (CG), a byproduct of coal mining, holds potential for use in catalytic oxidation of pollutants. Zeolitic imidazolate framework-67 (ZIF-67) is commonly employed to activate sulfate systems, serving as a highly efficient Co-based heterogeneous catalyst that promotes the generation of strong oxidation species. However, there has been no relevant research on using CG to load ZIF-67 for the activation of H2O2 in pollutant degradation. In this study, ZIF-67/CG catalysts were prepared, with ZIF-67 and CG serving as precursors for the highly efficient activation of H2O2. X-ray photoelectron spectroscopy (XPS) and Fourier-transform infrared spectroscopy (FTIR) confirmed that ZIF-67/CG possesses a favorable ability to activate H2O2. The results revealed that the degradation efficiency of TC in the ZIF-67/CG/H2O2 system reached 82.8% within 60 minutes. Radical quenching experiments, electron paramagnetic resonance (EPR) analysis, and an analysis of the degradation mechanism identified that ･OH and 1O2 played major roles in TC degradation.