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In situ synthesis of visible-light-driven Z-scheme AgI/Bi2WO6 heterojunction photocatalysts with enhanced photocatalytic activity
摘要： In this work, an efficient visible-light-response AgI/Bi2WO6 heterojunction was successfully prepared via in situ precipitation of AgI nanoparticles on the aligned nanosheets of three-dimensional Bi2WO6 hierarchical microspheres for the first time. Studies suggested that the AgI/Bi2WO6 heterojunction exhibited excellent photocatalytic activity for tetracycline (TC) degradation compared to pure Bi2WO6 and AgI under visible light irradiation. Doping 20 wt% AgI resulted in the optimal TC photodegradation rate, which was 5.4 and 3.3 times higher than pure Bi2WO6 and AgI, respectively. The high-resolution transmission electron microscopy (HRTEM), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS) verified that Ag nanoparticles generated on AgI/Bi2WO6 heterojunction surface in photocatalytic degradation process, which was beneficial for promoting the rapid combination of electrons on the conduction band of Bi2WO6 with the holes on the valence band of AgI and the separation and transfer of photogenerated electron-hole pairs. Accordingly, the nontraditional transport pathway of photogenerated electrons and holes based on the Z-scheme system that consisted of Bi2WO6, AgI, and Ag was confirmed. Based on the systematic experimental evidence, the possible enhanced photocatalytic mechanism was proposed.
关键词： Z-scheme,Photocatalysis,Heterojunction,AgI/Bi2WO6,Tetracycline
更新于2025-09-23 15:23:52
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Enhanced photocatalytic activity of hydrogenated BiVO4 with rich surface-oxygen-vacancies for remarkable degradation of tetracycline hydrochloride
摘要： In this work, for the first time the hydrogenation treatment was employed to introduce oxygen vacancies on the surface of BiVO4 (BVO) particles, and the influence of hydrogenation on the morphological structure and photocatalytic activity of BVO was explored. Compared to the pristine BVO, a disordered amorphous layer was observed on the surface of the hydrogenated BVO (HBVO) sample. The disordered layer was due to the formation of surface oxygen vacancies in HBVO, as verified by X-ray photoelectron spectroscopy (XPS) and electron paramagnetic resonance (EPR) spectra. Meanwhile, the band gap of HBVO was slightly narrowed accompanying with a higher optical absorption ability. The photocatalytic measurements demonstrated that under 30 min visible light (λ ≥ 420 nm) illumination the HBVO sample could photocatalytically degrade 98% of tetracycline hydrochloride (TCH), which was much higher than the pristine BVO (~52%), and the calculated pseudo-first-order degradation rate constant (k) of HBVO (~0.118 min?1) was about 5 times that of BVO, confirming that the hydrogenation treatment could significantly improve the photocatalytic activity of BVO. In addition, the photocatalytic mechanism of HBVO for enhanced photocatalytic TCH removal was also discussed. The present work demonstrates the feasibility of employing the hydrogenation treatment to develop highly efficient visible light BVO-based photocatalysts for photocatalytic removal of antibiotics, and also deepens the understanding of the correlation between surface oxygen vacancies and photocatalytic performance of semiconductor photocatalysts.
关键词： BiVO4,Photocatalytic activities,Tetracycline hydrochloride removal,Hydrogenation,Surface oxygen vacancies
更新于2025-09-23 15:23:52
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Construction of flower-like MoS2/Ag2S/Ag Z-scheme photocatalysts with enhanced visible-light photocatalytic activity for water purification
摘要： Flower-like MoS2/Ag2S/Ag nanocomposites have been elaborately designed and synthesized successfully for the first time. The prepared MoS2/Ag2S/Ag nanocomposites as a novel photocatalysts present effective photocatalytic performance for the photodegradation of congo red (CR), tetracycline hydrochloride (TC-HCl) and disinfection for Pseudomonas aeruginosa (P. aeruginosa). For the photodegradation of TC-HCl, the effect of the pH of the initial solution and photocatalysts dosage was investigated. Furthermore, intermediates of TC-HCl degradation were verified by GC–MS analysis and the possible pathway of the photodegradation was also proposed. The electron paramagnetic resonance (EPR) technique and trapping experiments verified the electron transport path is Z-scheme system (PS-C-PS). Among them, Ag as an electron mediator enhanced the electron transmission rate and accelerated the separation efficiency of photogenerated carriers.
关键词： MoS2/Ag2S/Ag,Photocatalytic,Tetracycline hydrochloride,Water disinfection,Z-scheme
更新于2025-09-23 15:23:52
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A dual-cathode photoelectrocatalysis-electroenzymatic catalysis system by coupling BiVO4 photoanode with hemin/Cu and carbon cloth cathodes for degradation of tetracycline
摘要： When photoelectrocatalysis (PEC) couples with electroenzymatic catalysis (EEC), effective utilization of electrons from PEC process for yield of H2O2 plays an important role in the enzymatic catalysis. In the present work, we designed a novel dual-cathode PEC-EEC system for pollutant removal. In this system, BiVO4 photoanode was prepared by electrodeposition for visible light-driven PEC process while carbon cloth was used as the first cathode for electrogeneration of H2O2 and hemin/Cu prepared by electrophoretic deposition acted as the second cathode for enzymatic catalysis. The performances of the constructed dual-cathode PEC-EEC system were evaluated by decoloring Rhodamine B (RhB), which showed high decoloration percentage with acceptable stability and reusability. Further, the system was applied to degradation of tetracycline (TC), indicating that about 93.6% of TC was removed after 2-h treatment. A pathway for TC degradation in such a dual-cathode PEC-EEC system was proposed based on the intermediates determined by liquid chromatography coupled to mass spectrometry in tandem (LC-ESI-MS/MS).
关键词： BiVO4,Photoelectrocatalysis,Electroenzymatic catalysis,Tetracycline,Dual cathodes
更新于2025-09-23 15:23:52
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Removal of tetracycline by BiOBr microspheres with oxygen vacancies: Combination of adsorption and photocatalysis
摘要： Oxygen vacancy-containing BiOBr microspheres with dual functions of adsorption-photocatalysis were synthesized by a simple solvothermal method. The as-prepared samples were characterized by X-ray diffraction (XRD), field-emission scanning electron microscopy (FESEM), X-ray photoelectron spectroscopy (XPS), electron paramagnetic resonance spectroscopy (EPR) and UV–vis diffuse reflectance spectroscopy (DRS). BiOBr microspheres with oxygen vacancies exhibited a higher adsorptive and photocatalytic activity for the removal of tetracycline (TC) than that of defect-deficient BiOBr microspheres. After adsorption for 30 min and visible light irradiation for 90 min, about 94 % of TC was removed by oxygen vacancy-containing BiOBr microspheres, and TC removal efficiency performed effectively in a wide pH range from 3.1 to 11.00. Almost all inorganic anions, such as Cl?, SO2?4, PO3?4, CO2?3 and NO?3, inhibited the removal of TC by BiOBr microspheres and their inhibition effects followed the order of PO3?4 > SO2?4 > CO2?3 > Cl? > NO?3. The surface hydroxyl groups had no effect on TC adsorption, and the adsorption of TC on BiOBr was mainly through the anion exchange process. The existence of oxygen vacancies facilitated the generation of superoxide radicals (O2??), which were the dominant reactive oxygen species for TC degradation in BiOBr suspension. The adsorptive and photocatalytic performance of oxygen vacancy-containing BiOBr decreased to different degrees after three cycles mainly due to the formation of surface complex.
关键词： Mechanism,Photocatalysis,Oxygen vacancy,Adsorption,BiOBr microspheres,Tetracycline
更新于2025-09-23 15:23:52
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Novel RGO and concave cube Cu <sub/>2</sub> O co-modified BiVO <sub/>4</sub> nanosheets with enhanced photocatalytic and surface adsorption performances of tetracycline
摘要： A novel ternary Cu2O/BiVO4/RGO photocatalyst is successfully constructed by hydrothermal and evaporation-induced method, and it exhibits superior photocatalytic performance for degradation tetracycline (TC). Meanwhile, the visible light absorption range of composite photocatalyst is effectively broadened by the formation of heterojunction with narrow band gap semiconductor Cu2O. And the separation efficiency of the photogenerated electron-hole pairs is significantly enhanced by the synergistic effect of Cu2O and RGO. More importantly, the adsorption of TC by ternary Cu2O/BiVO4/RGO possesses high adsorption capacity, which is 23.73 times higher than that of pure BiVO4. Additionally, the possible reaction mechanism is clearly revealed by radical trapping experiment, electron spin-resonance (ESR) spectroscopy. This work provides a new insight to design a photocatalyst with excellent adsorption to remove organic contaminants in water.
关键词： RGO,Adsorption,synergistic effect,BiVO4,Cu2O,Tetracycline
更新于2025-09-23 15:22:29
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Peroxymonosulfate enhanced antibiotic removal and synchronous electricity generation in a photocatalytic fuel cell
摘要： Photocatalytic fuel cell (PFC) is promising owing to its synchronous organic pollutants removal and energy recycle, but it still remains to improve in the cell performance. Herein, we demonstrate a synergistic method adding peroxymonosulfate (PMS) into PFC to promote antibiotic tetracycline (TC) degradation and simultaneous electric power generation. The introduction of PMS could be activated by the photoelectric effects, also used as the electrolyte and electron acceptor, which could enhance the photoelectrocatalysis and spread the reaction space from the electrode surface to the whole system. Herein, the PFC/PMS augmented the TC decontamination by 82.83% and electricity production by 122.40% versus the PFC without introducing PMS, respectively. In addition, factors controlled namely PMS dosage, solution pH, and UV intensity were investigated for the cell performance of the coupling system. Furthermore, UVeVis spectrum and TOC analysis con?rmed the destruction mineralization of TC. Moreover, a series of radicals quenching experiments were implemented to explore the cooperative elimination mechanism, and the results indicated that hydroxyl and sulfate radicals played the key roles at the acidic condition, and the direct oxidation of PMS dominated the chief effect at the neutral environment, and singlet oxygen and superoxide anion acted the primary function in the alkaline circumstance.
关键词： Tetracycline degradation,Electricity production,Photocatalytic fuel cell,Peroxymonosulfate activation
更新于2025-09-23 15:22:29
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Sono-solvothermal fabrication of ball-flowerlike Bi2O7Sn2-Bi7O9I3 nanophotocatalyst with efficient solar-light-driven activity for degradation of antibiotic tetracycline
摘要： A novel Bi2O7Sn2-Bi7O9I3 nano-heterostructure photocatalyst with the different weighted percentages and as I-type heterojunction, which acts as pseudo-type II heterojunction, were successfully synthesized using sono-solvothermal manner for the first time. The coupled nanophotocatalysts with various weighted contents of Bi2O7Sn2 and Bi7O9I3 were characterized with XRD, FESEM, EDX, DRS, BET-BJH and pHpzc analyses. Meanwhile, the photocatalytic activity of various nanocomposites was evaluated in the remediation of the antibiotic tetracycline after 90 min irradiation. Results depicted that the ball-flowerlike Bi2O7Sn2(60)-Bi7O9I3(40) nanophotocatalyst, as a mesoporous structure and the type I-heterostructure which appears as an efficient solar-light-driven pseudo-type II heterojunction, represented the best photocatalytic efficiency. This is addressed by the suitable absorption of light range, high separation of charge carriers and its large surface area which provide more active sites for absorption of tetracycline molecules. Furthermore, to elucidate the how the influence of various parameters on the photodegradation efficiency, the different experiments were conducted over Bi2O7Sn2(60)-Bi7O9I3(40). The high activity was obtained in the medium with pH = 6, catalyst loading = 1 g/L and tetracycline concentration = 35 mg/L. Moreover, the capable of reusability and reaction mechanism of improved photodegradation on mentioned photocatalyst were investigated.
关键词： Sono-solvothermal,Water treatment,Antibiotic tetracycline,Photodegradation,Bi2O7Sn2-Bi7O9I3 nanophotocatalyst
更新于2025-09-23 15:22:29
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Degradation of tetracycline by solar photo-Fenton: Optimization and application in pilot photoreactor
摘要： The objective of this study is to analyze the photodegradation of the antibiotic tetracycline by the solar photo-Fenton process. The optimal conditions were obtained in a 22 (2 × 2) factorial design with the following input variables: reaction time and catalyst concentration (ferrous ion [Fe2+]). After statistical analysis using the Statistica 7.0 software, the optimal conditions determined, time = 120 min and Fe2+ = 166.81 mg/L, were applied in a pilot scale photoreactor, resulting in an 88.7% removal of the drug. In addition, in this stage we studied the reaction kinetics, biodegradability, and phytotoxicity of the products generated by the process. In the kinetic study, a constant of 1.82 × 10?2 min?1 was obtained. For this constant, a reaction time of 38.16 min is required for the initial tetracycline concentration to be reduced by 50%. The biodegradability tests indicated a gradual increase in the five-day biological oxygen demand/chemical oxygen demand ratio over time. The phytotoxicity tests showed an 18.5% decrease in the inhibition rate of the root growth of lettuce seedlings, indicating that the treatment applied reduces the toxicity of the substance.
关键词： photo-Fenton,photoreactor,solar photocatalysis,biodegradability,tetracycline,phytotoxicity
更新于2025-09-23 15:21:21
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The fabrication of floating Fe/N co-doped titania/diatomite granule catalyst with enhanced photocatalytic efficiency under visible light irradiation
摘要： Powdery photocatalyst has long been studied, yet its several disadvantages such as light-harvesting and recyclability in suspension system are the bottlenecks for practical application. The recent report on floating photocatalyst provided an alternative method to solve the above problem. In this work, TiO2 nanoparticles were co-doped by iron and nitrogen, and then dispersed onto natural porous mineral diatomite via sol-gel method. The composite powder was granulated to produce floating granule catalyst (Fe/N co-doped TiO2/diatomite hybrid granule), denoted as FN-TDHG. Its various physicochemical properties such as light absorbance, crystallinity, surface condition as well as morphology were systematically analyzed. The synergy between Fe and N dopants, as well as diatomite and TiO2 were studied. The photoactivity of FN-TDHG was investigated via the degradation towards tetracycline (TC) solution under visible light irradiation, and then the optimal co-doping amount and granule dosage were determined. The optimal granule catalyst presented its removal rate of TC as 96.5% within 150 min. Moreover, floating FN-TDHG could simply be filtrated from the surface of water matrix, and presented good reusability after 5 repetitions. This photocatalytic granule is hopefully considered suitable to be applied in environmental remediation.
关键词： Fe/N co-doped,Diatomite,Floating,Visible light,Tetracycline
更新于2025-09-23 15:21:21