Photocatalytic Degradation Of Tetracycline Hydrochloride Research Articles

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.

Photocatalytic degradation of tetracycline hydrochloride using a BiVO4/MIL-88B(Fe) heterojunction

A type II heterostructured BiVO4/MIL-88B(Fe) composite was successfully synthesised for the photocatalytic degradation of tetracycline hydrochloride (TC-HCl) by a simple hydrothermal method.

Construction of a SnS2/TiO2 S-scheme heterostructure photocatalyst for highly efficient photocatalytic degradation of tetracycline hydrochloride

A schematic diagram of the catalytic mechanism of photocatalytic degradation of tetracycline hydrochloride pollutant by Sn2/TiO2 S-scheme heterostructure photocatalysts in water.

Bifunctional S-scheme CdSSe/Bi2WO6 heterojunction catalysts exhibit generalized boosting performance in photocatalytic degradation of tetracycline hydrochloride, photoelectrochemical and electrocatalytic hydrogen production

In this work, by a simple method of hydrothermal synthesis, the CdSSe/Bi2WO6 S-scheme heterojunction catalyst is successfully obtained and the results are verified by XPS, EPR, band structure, etc. The S-scheme heterojunction can maintain the strong redox potential energy position of both catalysts, and adjust the electron transfer path to improve the electron-hole separation efficiency, and thus improve the charge transfer efficiency. CdSSe has a high conduction band (−1.13 eV) and a narrow bandgap width (1.59 eV), exhibiting good light absorption characteristics and reduction ability; the valence band position of Bi2WO6 is much low (2.58 eV), indicating good oxidation activity. This heterojunction has excellent oxidation and reduction capabilities and exhibits multifunctional catalysts. Its photocatalytic degradation ability of tetracycline hydrochloride is 2.2 times that of the original CdSSe, while its photoelectrochemical activity is 11 times that of CdSSe, reaching a photocurrent density of − 2.081 mA/cm2 at 0 V (vs. RHE). The electrocatalytic activity of its hydrogen evolution has also been enhanced. This study developed a design strategy for a novel bifunctional S-scheme heterojunction catalyst.

Construction of Z-scheme heterojunction LaCoO3 modified ZnO for photocatalytic degradation of tetracycline under visible light irradiation

The Z-scheme LaCoO3/ZnO (LCZ) heterojunction photocatalyst was designed and prepared using the hydrothermal method. In the photocatalytic degradation of tetracycline hydrochloride, LCZ exhibited the highest photocatalytic activity with a rate constant of 0.0179 min−1,which is 3.2 and 2.3 times higher than those of pure ZnO and LaCoO3, respectively. This study presents a promising approach with potential applications in the field of photocatalytic degradation. Further theoretical studies reveal that the existence of Z-scheme heterojunction can prevent the recombination of electron-hole pairs, leading to enhanced photocatalytic performance.

Design of Co-doped carbon nitride based on melem supramolecular assembly with enhanced photocatalytic activity toward tetracycline hydrochloride degradation

We design highly-active porous Co-doped carbon nitride (CN) rod by a facile thermal condensation of melem supramolecular assembly incorporated with Co species. The highly thermal-stable H-bonded melem supramolecule enables less and slow sublimation during the thermal condensation process, ensuring good microstructural integrality of the CN skeleton for the migration of photogenerated carriers. And the Co doping can further modulate the electronic, optical, and catalytic properties of the catalyst. The best-performing Co-doped CN catalyst demonstrates desirable performance toward the photocatalytic degradation of tetracycline hydrochloride (10.3 times higher than that of bulk CN) and good cycling stability maintaining 80.0 % after 5 reuses.

Photocatalytic degradation of tetracycline hydrochloride by ZnO/TiO2 composite photocatalyst

Photocatalytic degradation of tetracycline hydrochloride by ZnO/TiO2 composite photocatalyst

Symmetry breaking induced local electron rearrangement to enhance photocatalytic tetracycline hydrochloride oxidation and hydrogen evolution of carbon nitride

A symmetry breaking strategy was achieved by a sample doping approach and used to overcome the sluggish carrier transfer and insufficient light capture capacity of carbon nitride photocatalysts. The obtained local electronic structural reconstruction resulted in the generation of an intermediate energy level, which can regulate the band gap structure and boost the redox reaction progress. Furthermore, the DFT calculation results prove the electronic structure rearrangement brings adsorption characteristic changes for H2O and O2 molecules, leading to the variation of free radicals’ generation. Combing the advantages of band gap structure optimization and internal electron rearrangement, the phosphorus doped carbon nitride achieves a balance between light absorption properties and photocatalytic redox capacity, exhibiting stronger reduction capacity, high carrier separation efficiency, and optimized adsorption sites. Consequently, the phosphorus doped carbon nitride shows enhanced activities in photocatalytic tetracycline hydrochloride degradation (3.6-fold increase), peroxydisulfate activation (4.5-fold increase), and hydrogen generation (13.5-fold increase) compared to pristine carbon nitride. This research highlights the symmetry regulation strategy as a promising method for developing highly efficient multifunctional carbon nitride-based photocatalysts.

MXene derived Ti3C2/TiO2/Ag persistent photocatalyst with enhanced electron storage capacity for round-the-clock degradation of organic pollutant

Persistent photocatalysis has garnered significant attention due to its ability to sustain catalytic activity in dark by storing electrons. However, the practical application of persistent photocatalysis is hindered by limited electron storage capacity. Herein, we synthesized and demonstrated that Ti3C2/TiO2/Ag persistent photocatalyst has good electron storage capability. The electron storage capacity of Ti3C2/TiO2/Ag is up to 0.125 μmol/mg, which is 2.5 times that of Ti3C2/TiO2. The enhanced electron storage capacity resulted in improved dark-reaction activity because more electrons react with oxygen to form more radicals, as evidenced by degradation experiments of various organics. Especially, persistent photocatalytic degradation of tetracycline hydrochloride by Ti3C2/TiO2/Ag was achieved under natural outdoor conditions (from 2:00p.m. to 8:00p.m.). Additionally, the aid of oxidants such as peroxymonosulfate (PMS) can further improve the dark-reaction activity. TiO2/Ti3C2/Ag/PMS system exhibits excellent efficacy in removing tetracycline hydrochloride, oxytetracycline, rhodamine b, methyl orange, and methylene blue, with removal rates reaching 79.5 %, 81.4 %, 98.9 %, 99.1 %, and 99.2 %, respectively (15 min of light-reaction and 45 min of dark-reaction). This work provides a new strategy to enhance electron storage capacity and demonstrates that decoupling of light-reaction and dark-reaction may provide a new opportunity for photocatalytic removal of pollutants around the clock.

Refining the d-band center of S-scheme CdIn2S4/MnZnFe2O4 heterostructures by interfacial electric field with boosting photocatalytic performance

The low activity of photocatalysts is mainly due to inefficient charge separation and low production of the active species. To overcome this challenge, we constructed an S-scheme CdIn2S4/MnZnFe2O4 (CIS/MZFO) heterostructure, where the strong interface of the heterostructure leads to an upshift of the d-band center. CIS/MZFO shows higher charge transfer efficiency and oxygen adsorption/activation performance compared to CIS and MZFO separately, thereby increasing the production of ·O2− and h+ active species. As a result, it demonstrats efficient photocatalytic degradation of tetracycline hydrochloride. The optimized CIS/MZFO heterostructure also shows good tolerance to various factors, such as inorganic ions, organic acids, pH and real water environments. The heterostructure also exhibits excellent magnetic recyclability and stability. Additionally, we propose a photocatalytic degradation pathway for tetracycline hydrochloride and evaluate the ecological toxicity that may arise from intermediates. This study provides an effective approach for the design of advanced photocatalysts.

Photocatalytic Degradation of Tetracycline Hydrochloride by Mn/g-C3N4/BiPO4 and Ti/g-C3N4/BiPO4 Composites: Reactivity and Mechanism

The environmental pollution caused by antibiotics is becoming more serious. In this study, the Mn/BiPO4/g-C3N4 composite (Mn-BPC) and the Ti/g-C3N4/BiPO4 composite (Ti-BPC) were prepared by hydrothermal reaction method and solvent method, respectively, and applied to the degradation of tetracycline (TC) in an aqueous environment. The XRD and HRTEM results showed that these materials had the crystalline rod-like structure of BiPO4 and abundant carbon, nitrogen and carbon–oxygen surface functional groups. The degradation of TC by Ti-BPC and Mn-BPC were nearly 92% and 79%, respectively. The degradation processes of TC were well consistent with the pseudo-second-order kinetics model and R2 values were closer to 1. The trapping experiment showed that electron holes (h+) were the main reactive species for the degradation of tetracycline, OH· and O2− also have certain effects. Also, the possible photocatalytic degradation mechanism of Ti-BPC and Mn-BPC composites was thereby proposed. TC was firstly adsorbed on the surface of catalysts, and subsequently degraded by reactive species such as h+, OH· and O2− generated under visible light excitation. This study shows that the Ti-BPC and Mn-BPC photocatalysts have great potential in antibiotic degradation and can provide new ideas for antibiotic removal in aqueous environments.

Rapid synthesis of in situ nitrogen-doped ZnO nanoparticles for visible-light-driven photocatalytic removal of emerging contaminants

The effective functionalization of photocatalysts suitable for removing emerging contaminants poses a significant challenge. This study proposes a novel and rapid method for synthesizing in situ nitrogen-doped ZnO nanoparticles to address these limitations. Using a combustion synthesis scheme, we modified the urea-to-sucrose ratio and oxide precursors to characterize the catalysts systematically. The resulting material exhibited a remarkable 40% increase in visible-light-driven photocatalytic degradation of tetracycline hydrochloride (TC-HCl) over undoped ZnO. A maximum photocatalytic efficiency of 74.7% (60 min) was achieved by incorporating 50% urea in the fuel, which provided N–ZnO with a size of 120 nm, a surface area of 26 m2/g, mesoporosity, and a bandgap of 2.89 eV. With the rapid synthesis, this work surpassed the values reported in the literature. Moreover, this study presents a pathway for catalyst regeneration, underscoring the significance of the method and its potential in photocatalysis.

Novel Z-scheme MgFe2O4/Bi2WO6 heterojunction for efficient photocatalytic degradation of tetracycline hydrochloride: Mechanistic insight, degradation pathways and density functional theory calculations

In this study, a new Z-scheme MgFe2O4/Bi2WO6 heterojunction was successfully prepared by hydrothermal and wet ball milling process. The results of the study showed that after 90 min of visible light exposure, the photocatalytic degradation of tetracycline hydrochloride (TCH) by 25%-MgFe2O4/Bi2WO6 heterojunction was as high as 95.82%, and the highest photocatalytic rate (0.0281 min−1) was 4.61 and 3.43 times higher than that of pure Bi2WO6 (0.0061 min−1) and MgFe2O4 (0.0082 min−1), respectively. Furthermore, spin-polarized density functional theory (DFT) calculations were performed to provide additional evidence of the presence of a Z-scheme charge transfer mechanism between MgFe2O4 and Bi2WO6. We investigated the effects of initial TCH concentration, pH, coexisting ions and different water sources on the efficiency of photocatalytic degradation of TCH in composite samples. The recovery experiments demonstrated that the MgFe2O4/Bi2WO6 composites had good stability and repeatability. A series of experimental results showed that 25%-MgFe2O4/Bi2WO6 had a larger specific surface area, better ultraviolet and visible absorbance, superior charge transfer and higher efficiency of photogenerated electron-hole pair separation. This paper provides new ideas for the design and preparation of new Z-scheme heterojunctions and has great prospects for practical applications in the field of wastewater treatment.

Dual-channel charge transfer over g–C3N4/g–C3N4/bismuth-based halide perovskite composite for improving photocatalytic degradation of tetracycline hydrochloride

Photocatalytic technology represents a cutting-edge approach for addressing water pollution. The performance of photocatalysts can be improved by constructing of heterojunctions that facilitate the charges transfer between the two components. Herein, we produced a three-component g–C3N4/g–C3N4 isotype heterojunction/bismuth-based halide perovskites (g–C3N4–ISO/BHP) composite using a solvothermal method to grow bismuth-based halide perovskite (BHP) onto the surface of g–C3N4/g–C3N4 isotype heterojunction (g–C3N4–ISO) layers. Several methods were used to investigate crystalline structure, morphology, chemical composition/states, optical characteristics, and charge-carrier dynamics of the three-component composite. The g–C3N4–ISO/BHP composite exhibited superior photocatalytic activity under white LED light with a degradation percentage of 73.2%, which is higher than the mixed-phase g–C3N4–ISO (61.4%) and the bare BHP (62.5%). The control of component content improved the transmission of charges between the composite components. The S-scheme charge transfer mechanism was verified to function on the g–C3N4–ISO/BHP composite as a result of its high compatibility and adequate band structure, resulting in robust redox ability, effective charge carrier separation and extended lifetime. Our study presents a practical approach for constructing three-component composites for efficient photocatalytic water treatment.

Preparation of phosphorus-doped mesoporous g-C3N4 and its photocatalytic degradation of tetracycline hydrochloride

P-doped tunnel-shaped carbon nitride is prepared for the first time using phosphonitrilic chloride trimer as P source and SBA-15 as template. The optimization experiments reveal that 20% P doped tunnel-shaped carbon nitride exhibited the best tetracycline hydrochloride (TC) degradation performance under visible light irradiation. The degradation rate constant is 0.23367 min−1, which is around 3 and 30 times faster than that of carbon nitride without P doping (0.07223 min−1) and without SBA-15 as template (0.00078 min−1). Radical capture experiment shows that h+ and ∙O2− are the main reactive radicals in the photocatalytic degradation process. The doped P element can increase the formation rate of ∙O2− and reduce the combination of photogenerated electron-hole pairs due to the presence of electron capture centers. The photocatalytic mechanism of P-doped tunnel-shaped carbon nitride is proposed, providing experimental data and theoretical basis for the practical application in polluted wastewater.

Promoted photocatalytic degradation of tetracycline hydrochloride by montmorillonite catalyst loaded with Cu/Mn

Promoted photocatalytic degradation of tetracycline hydrochloride by montmorillonite catalyst loaded with Cu/Mn

Visible-light-driven AgI/Bi4O5I2 S-scheme heterojunction for efficient tetracycline hydrochloride removal: Mechanism and degradation pathway

The existence of excessive tetracycline hydrochloride (TCH) in the ecological environment has seriously threatened human health, so there is an urgent need to develop a high-performance photocatalyst that can efficiently and greenly remove TCH. Currently, most photocatalysts have the problems of fast recombination of photogenerated charge carriers and low degradation efficiency. Herein, S-scheme AgI/Bi4O5I2 (AB) heterojunctions was constructed for TCH removal. Compared with the single component, the apparent kinetic constant of the 0.7AB is 5.6 and 10.2 time as high as the AgI and Bi4O5I2, and the photocatalytic activity only decreases by 3.0% after four recycle runs. In addition, to verify the potential practical application of the fabricated AgI/Bi4O5I2 nanocomposite, the photocatalytic degradation of TCH was performed under different conditions by regulating the dosage of photocatalyst, the TCH concentration, pH, and the existence of various anions. Systematical characterizations are conducted to investigate the intrinsic physical and chemical properties of the constructed AgI/Bi4O5I2 composites. Based on the synergetic characterizations by in situ X-ray photoelectron spectroscopy, band edge measurements, as well as reactive oxygen species (ROS) detections, the S-scheme photocatalytic mechanism is proved. This work provides a valuable reference for developing efficient and stable S-scheme AgI/Bi4O5I2 photocatalyst for TCH removal.

Synthesis of novel MnFe2O4/BiOI green nanocomposite and its application to photocatalytic degradation of tetracycline hydrochloride: (LC-MS analyses, mechanism, reusability, kinetic, radical agents, mineralization, process capability, and purification of actual pharmaceutical wastewater)

Antibiotics in water bodies pose a serious threat to public health and the environment, leading to increased efforts to eliminate them from wastewater. In this study, a green nanocomposite catalyst of MnFe2O4/BiOI and Calendula officinalis was evaluated for its ability to decompose tetracycline in simulated sunlight. Characterization techniques including DRS, DLS, VSM, FTIR, XRD, TEM, FESEM, EDX, LC-MS, and pHpzc were used, revealing MnFe2O4/BiOI 's average crystal size of 14.47 nm, band gap of 1.7 eV, and magnetic saturation of 23.63 emu/gr. Under optimal conditions of a pH level of 9, tetracycline concentration of 20 mg/L, MnFe2O4/BiOI dosage of 0.5 g/L, and a reaction time of 200 min, the MnFe2O4/BiOI catalyst effectively broke down tetracycline, resulting in complete degradation. The pseudo-first-order equation accurately predicted degradation rates, and reusability tests showed only a 5% drop in efficiency after six cycles. The recommended method achieved high mineralization rates, with COD and TOC elimination efficiencies of 83.04% and 61.45%, respectively. Maximum removal efficiency for TOC and COD in pharmaceutical wastewater was achieved after 200 min, with 44.73% and 57.19%, respectively. Under optimal conditions, with 20 mg/L of tetracycline and sunlight exposure, the maximum tetracycline removal rate was 76.02%. This study demonstrated that the MnFe2O4/BiOI catalyst-based Xenon-photocatalytic approach is effective and adaptable for treating wastewater containing antibiotics from drug production and manufacturing processes.