Degradation Of Tetracycline Hydrochloride Research Articles

Novel high entropy alloy/NiAl2O4 photocatalysts for the degradation of tetracycline hydrochloride: Heterojunction construction, performance evaluation and mechanistic insights

Novel NiAl2O4 (NAO)/high entropy alloy (HEA) (Ti), NAO/HEA (Mn) and NAO/HEA (Mo) heterojunction photocatalysts with high photocatalytic activity for the degradation of tetracycline hydrochloride (TC) under simulated sunlight irradiation were synthesized by the polyacrylamide gel method combined with a low temperature sintering technique. The effects of environmental parameters, including drug concentration, catalyst content and pH value, on the photocatalytic activity of NAO/HEA photocatalysts were investigated in detail on the basis of the response surface methodology (RSM) and experimental results. The optimal initial TC concentration, catalyst content, and pH were 100 mg/L, 1 g/L, and 5, respectively. The photocatalytic activity of NAO/HEA photocatalyst (84.6 %) was significantly improved compared to the degradation percentage of HEA (Ti) photocatalyst (36.5 %). The roles of active free radicals including h+, •O2−, •OH and oxygen vacancy in photocatalysis were verified using multiple characterization methods. In-depth analysis was conducted on the degradation pathway of TC, the safety of degradation intermediates, and the photocatalytic mechanism of NAO/HEA (Ti) photocatalyst. The Z - scheme heterojunction can significantly improve the transport efficiency of photogenerated carriers and inhibit the recombination rate of electron hole pairs in the system, which provides a new idea for exploring the application of new HEA - based heterojunction photocatalysts in the field of photocatalysis.

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

Construction of effectively dispersible CoTiO3/kaolinite catalysts: Enhanced degradation of tetracycline hydrochloride over peroxymonosulfate activation

Novel CoTiO3/kaolinite (CTO/Kaol) composites were synthesized using a two-step method, successfully integrating nanoparticles with natural minerals. Transmission electron microscopy and N2 adsorption–desorption isotherms indicated that the CTO particles were uniformly dispersed across the kaolinite substrate, exhibiting a substantial specific surface area and porosity conducive to persulfate adsorption and activation. Remarkably, the CTO/Kaol30%/peroxymonosulfate (PMS) system demonstrated superior catalytic efficiency for tetracycline hydrochloride (TCH) degradation compared to pristine CTO and kaolinite, achieving 91.2% decomposition within 20 min and maintaining high efficiency across a pH range of 4–11. Probing via electron paramagnetic resonance (EPR), reactive oxygen species (ROS) quenching, and electrochemical analyses corroborated synergistic interactions within the radical/non-radical pathways—crucial for pollutant abatement. Singlet oxygen (1O2) emerged as the principal reactive species propelling degradation, while sulfate radicals (SO4•−) played a complementary role. Beyond TCH, the CTO/Kaol30% composite exhibited potent degradation and mineralization capabilities for diverse antibiotics, including sulfamethoxazole, chlortetracycline, and ciprofloxacin. This investigation provides insight into the design of high-performance kaolinite-based catalytic systems, fostering the broader application of Fenton-like processes in the remediation of antibiotic-laden aqueous environments.

Dual electron microregion with oxygen vacancy of Fe0.8La/MCM-48 in bridging peracetic acid and ozonation: Taking the pathway of free radical or nonradical generation?

Efficient tetracycline hydrochloride (TCH) degradation and interface reaction mechanism were investigated by constructing nonradical pathways in heterogeneous peracetic acid coupling with ozonation (O3/PAA) process. Ball-milling assisted Fe–La anchoring MCM-48 catalysts with dual electron microregion was designed to trigger 1O2-dominated non-radical for strong immunity to environment interference. Results exhibited that 83.4% degradation efficiency of TCH was achieved by Fe0.8La/MCM-48/O3/PAA system in only 2 min and 94% TCH was degraded in a 12-hour continuous flow experiment. La with oxygen vacancy regulated the local atomic environment and electron structure of Fe sites, which could initiate peracetic acid activation to promote 1O2 production by surface adsorbed atomic oxygen (*Oad) reaction and this process overcame a lower reaction energy barrier than the binding of surface *Oad to O3. This work offers a reasonable interpretation for Fe–La synergy for inducing non-free radical route, which furnishes theoretical support and practical application for heterogeneous O3/PAA.

Construction of a novel Cu2(OH)3F/Cu2O n-p heterojunction by in-situ reduction: photo-Fenton-like synergistic promotion of efficient Cu2+/Cu+ cycling

Cu-based Fenton-like systems have demonstrated high effectiveness in the degradation of organic pollutants, however, challenges still exist to overcome the sluggish cycling of metal ions and fast activation of reactants. Herein, a novel n-p type Cu2(OH)3F/Cu2O photo-Fenton-like catalyst (CFC) was prepared with in-situ reduction of Cu2(OH)3F and applied for tetracycline hydrochloride degradation. Under optimized condition, the target catalyst (CFC-5) showed excellent activity, achieving a degradation efficiency of approximately 99.93 % in 30 min. The reaction rate constant with CFC-5 was 4.10 and 3.26 times higher than that of Cu2(OH)3F and Cu2O, respectively. Moreover, the Cu2(OH)3F/Cu2O catalyst exhibited highly cycling stability and broad applicability. The results illustrate that construction of Cu2(OH)3F/Cu2O composites facilitates the charge separation and enhances Cu2+/Cu+ cycling, which benefits the generation of highly oxidizing active species and thus significantly improved the degradation efficiency. Besides, this study offers a versatile method to construct inexpensive and efficient photo-Fenton-like heterojunction catalysts.

β-NaGdF4:Yb,Er@CdS/MWCNTs photocatalysts with efficient interfacial energy migration for full-spectrum light-driven antibiotic degradation: Construction and DFT insight

Currently, upconversion nanoparticles (UCNPs) based photocatalysts have been extensively developed to improve solar energy utilization. However, the mechanisms underlying interfacial energy migration of upconversion photocatalyst remain unclear. Herein, a promising composite photocatalyst with complementary properties is designed by integrating β-NaGdF4:Yb3+/Er3+ (NGFYE), CdS and multi-walled carbon nanotubes (MWCNTs). The morphology, structure and chemical properties of NGFYE@CdS/MWCNTs ternary photocatalyst are characterized. In addition, the existence of Förster resonance energy transfer process in NGFYE@CdS/MWCNTs photocatalysts, i.e., the migration of excitation energy from Er3+−4S3/2 excitation level and higher excitation level (e.g., Er3+−2H11/2) to CdS nanoparticles, was further confirmed by density functional theory (DFT) calculations. The optimized NGFYE@CdS/MWCNTs photocatalyst presents 71.65 % and 35.29 % degradation of tetracycline hydrochloride (TCH) and ciprofloxacin (CIP) under λ ≥ 800 nm irradiation for 3 h, respectively. This work not only illustrates the interfacial energy migration mechanism between NGFYE and CdS, but also provides insights for the rapid construction of heterojunction materials with efficient energy transfer interfaces.

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.

Mg–Fe Layered Double Hydroxides/Polyacrylonitrile Nanofibers for Solar-Light Induced Peroxymonosulfate Elimination of Tetracycline Hydrochloride

The photo-induced peroxymonosulfate (photo-PMS) reaction is a promising route to eliminate antibiotics from waste water. To achieve excellent photo-PMS activity in Mg–Fe layered double hydroxides (LDHs) for tetracycline hydrochloride (TCH) degradation under simulative solar-light irradiation, Mg–Fe LDHs-loaded polyacrylonitrile (Mg–Fe/PAN) nanofibers were in-situ prepared via the hydrothermal route. For comparison to the photocatalysis and photo-PMS process, the Mg–Fe/PAN-assisted photo-PMS process exhibited a better elimination activity for TCH elimination. In addition, the photo-PMS activities of Mg–Fe/PAN composites were greatly affected by Mg–Fe LDHs content, TCH concentration, pH, and inorganic salts. Among these Mg–Fe/PAN composites, the optimal MgFe2/PAN with a Mg/Fe molar ratio of 1:2 and a nominal Mg–Fe LDHs content of 2.0 wt. % removed 81.31% TCH solution of 80 mg L−1 TCH within 120 min. This enhanced photo-PMS capacity of MgFe2/PAN was ascribed to the abundant active sites formed by functional groups and oxygen defects for efficient TCH species adsorption and photon capturing, and the tight interface between Mg–Fe LDHs nanoparticles and PAN nanofibers for the rapid separation and transfer of photoinduced e−/h+ pairs. SO4•− and •O2− radicals were vital for the MgFe2/PAN-assisted photo-PMS reaction.

Facile ligand-regulated synthesis of defective Fe-MOF nanosheets for efficient tetracycline degradation via photoassisted enhanced activation of persulfate

In this work, defective Fe-based metal organic framework (Fe-MOF) were synthesized by a simple and eco-friendly method, in which the benzenetricarboxylic acid (BTC) ligand was partially replaced by cheap terephthalic acid (TPA) to regulate the crystalline morphology, pore structure and ligand defects. At BTC/TPA = 5/3, 4/4 and 3/5 (molar ratio), lamellar crystal (1-Fe-MOF), a mixture of lamellar crystal and nanosheets (2-Fe-MOF), and nanosheets (3-Fe-MOF) were obtained, respectively, which were distinctly different from the octahedral Fe-MOF. In the visible-light-driven persulfate (PS) activation coupled system, 3-Fe-MOF exhibited highest catalytic activity for tetracycline hydrochloride (TCH). 96.5% of TCH was removal within 20 min and the degradation kinetics rate of 0.144 min−1 was 3.5 times higher than that over the intact Fe-MOF. The enhancement in degradation activity was mainly attributed to the emergence of mesoporous structure, exposure of more metal active sites, and accelerated Fe2+/Fe3+ cycling due to more efficient charge separation and electron transfer efficiency, which favored the generation and dominant role of ∙SO4− in TCH degradation. Furthermore, demethylation, deamidation, double-bond oxidation and ring-opening reactions were inferred as the two possible degradation pathways of TCH in 3-Fe-MOF/PS/Vis system. This study provides useful guidance for the design of novel and sustainable MOFs with good application performance and industrialization potential.

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.

Dual ligands and crosslinking atoms relayed MOF anode for tetracycline hydrochloride electrocatalytic decontamination: Efficiency and mechanism

MOF anodes were especially prepared with dual-ligand and S/N crosslinking atoms for tetracycline hydrochloride (TCH) electrocatalytic degradation. Results showed S(HTTP)-Ni-N(HAB) and N(HITP)-Ni-S(BHT) exhibited high electrocatalytic performance with 100% TCH degradation in 10 min, which were superior to that of S(HTTP)-Ni-S(BHT) and N(HITP)-Ni-N(HAB). The experimental and DFT calculation results jointly unraveled that the electron delocalization created by adjacent S/N crosslinking atoms facilitated the electron conduction and produced positive-charged Ni sites for the improved generation of ·O2− and ·OH radicals. The positive contributions of ·O2− and ·OH radicals then proved the degradation pathways of TCH. In addition, extended experiments on various conditions and pollutions highlighted the application potential of S/N hybrid MOF anodes. The final results provided new insight into MOF anode design and preparation via large cardinal ligand and crosslinking atom adjustment for environmental application.

Bi-Doped and Bi Nanoparticles Loaded CeO2 Derived from Ce-MOF for Photocatalytic Degradation of Formaldehyde Gas and Tetracycline Hydrochloride.

Bi/CeO2 (BC-x) photocatalysts are successfully prepared by solvothermal loading Bi nanoparticles and Bi-doped CeO2 derived by Ce-MOF (Ce-BTC). Formaldehyde gas (HCHO) and tetracycline hydrochloride (HTC) are used to evaluate the photocatalytic activity of the synthesized Bi/CeO2. For BC-1000 photocatalyst, the degradation of HTC by 420nm < λ < 780nm light reaches 91.89% for 90min, and HCHO by 350nm < λ < 780nm light reaches 94.66% for 120min. The photocatalytic cycle experiments prove that BC-1000 has good cyclic stability and repeatability. The results of photoluminescence spectra, fluorescence lifetime, photocurrent response, and electrochemical impedance spectroscopy showed that the SPR (Surface Plasmon Resonance) effect of Bi nanoparticles acted as a bridge and promoted electron transfer and enhanced the response-ability of Bi/CeO2 to visible light. Bi-doping produced more oxygen vacancies to provide adsorption sites for adsorbing oxygen and generated more ·O2 - thus promoting photocatalytic reactions. The mechanism of photocatalytic degradation is analyzed in detail utilizing active free radical capture experiments and electron paramagnetic resonance (EPR) characterization. The experimental results indicate that ·O2 - and h+ active free radicals significantly promote the degradation of pollutants.

Rapid degradation of high-concentration antibiotic via heterogeneous photocatalysis coupling Fenton-like oxidation with MIL-53(Fe) under visible light irradiation

The photocatalytic technology based on Metal-Organic Frameworks (MOFs) has shown promising applications in the field of antibiotic pollution control. However, it still faces challenges in efficiently removing high-concentration antibiotic wastewater. A typical Fe-containing MOF, MIL-53(Fe), was successfully synthesized and demonstrated efficient photocatalytic activity under visible light irradiation for high-concentrations of tetracycline hydrochloride (TCH). However, the bare MIL-53(Fe) exhibited unsatisfactory photocatalytic performance. To overcome the low degradation efficiency resulting from the rapid recombination of light-induced electron-hole pairs, H2O2 was introduced as an external electron acceptor to establish a synergistic Fenton-like system to couple with the photocatalysis process. The results showed that in the MIL-53(Fe)/H2O2/Vis system, 99% of 1 g/L TCH was degraded within 80 min, while the degradation efficiency of the MIL-53(Fe)/Vis process was only 4.89% under identical conditions. The degradation mechanism of the coupling system was performed by radical scavenging experiments and Electron Spin Resonance characterization. The results indicated that ·OH was the dominant radical in the coupled reaction, and ·O2- and h+ also played a role in this system. The significant improvement in TCH degradation efficiency during the coupling process was attributed to the following three factors: (1) In the coupling reaction process, photo-generated electrons can stimulate H2O2 to form ·OH radicals, inhibiting the recombination of photo-generated electrons and holes, improving the efficiency of the photocatalytic reaction. (2) FeIII in MIL-53(Fe) can be excited by photo-generated electrons and converted to FeII, which then stimulates H2O2 to form ·OH radicals. (3) FeIII in MIL-53(Fe) can convert with FeII, stimulate H2O2 to form ·OH radicals, and participate in the degradation reaction. In addition, the reusability and stability of the MIL-53(Fe) photocatalyst in the coupled system, as well as the impact of operational parameters, were systematically studied. This work demonstrates a feasible strategy for environmental remediation by enhancing the efficiency of MIL-53(Fe) in photocatalytic Fenton-like systems, thereby providing a viable approach for the treatment of high-concentration antibiotic wastewater.

Rationally designed MIL-101(Fe)/WO3 S-scheme heterojunction coupled with peroxymonosulfate for boosting the visible-light-driven photodegradation of tetracycline hydrochloride

Developing S-scheme photocatalysts with excellent catalytic activity and convenient retrieval is highly desirable for wastewater purification. Herein, a novel S-scheme MIL-101(Fe)/WO3 heterojunction on carbon cloth is successfully synthesized via a facile solvothermal approach. The optimized MIL-101(Fe)/WO3 composite (MWC-1.5) has been found to be highly effective in activating peroxymonosulfate (PMS) and then degrading tetracycline hydrochloride (TC-HCl) with a 100% degradation rate when exposed to visible light (Vis) within a period of 20 min. Such MWC-1.5/PMS/Light system also shows stable cycling performance and good recyclability. The remarkable photocatalytic degradation performance is mainly attributed to the powerful intrinsic electric field that accelerates the separation of photogenerated charge carriers via the S-scheme charge transfer. Radical quenching experiments and electron paramagnetic resonance (EPR) results suggest that SO4– and OH are the major oxidizing substances in the photocatalytic processes. Three potential degradation pathways are deduced based on an in-depth analysis of the degradation intermediates and the degradation mechanism is also elucidated through a rational combination of the experimental studies and theoretical calculations. This novel hybrid photocatalyst system has been shown to be a promising strategy for environmental remediation, while also suggesting a feasible approach for the development of photocatalysts with both remarkable activity and stability.

Boosting solar-light photocatalytic activity of Ni2P-decorated ZnCr2O4 nanofibers for H2 evolution and tetracycline elimination

Photocatalysis is a promising route to convert solar light into chemical energy for H2 evolution and pollutants degradation. Hence, Ni2P decorated ZnCr2O4 (Ni2P/ZnCr2O4) nanofibers were prepared for boosting solar-light induced water splitting and tetracycline hydrochloride (TCH) degradation. For comparison to ZnCr2O4 nanofibers, Ni2P/ZnCr2O4 composites exhibited the better photocatalytic activities for water splitting and TCH removal. Owing to the co-catalytic effect of Ni2P for the efficient photon capture, the charge carriers were rapidly separated and migrated at the interface between Ni2P and oxygen-defected ZnCr2O4. H2 evolution rate of optimal C–Ni2P/ZnCr2O4 with a nominal Ni2P content of 9.0 wt% was 575.89 μmol g−1 h−1, and its apparent quantum yield at 420 nm was 15.25 %, while its H2 evolution decreased from 2815.13 to 2602.51 μmol g−1 after fifth cycle. In addition, the removal efficiency of C–Ni2P/ZnCr2O4 was 93.68 % within 90 min, and declined to 88.76 % after five cycles for solar-light driven degradation of 50 mg L−1 TCH solution. The deactivation of C–Ni2P/ZnCr2O4 was due to the photo-corrosion for the change in valence states of compositions.

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).

FeCo alloy nanoparticles supported on N-doped mesoporous carbon spheres for effective degradation of antibiotics and industrial dyes

Iron (Fe) is widely recognized for its effectiveness in the Fenton reaction and is commonly used in wastewater treatment. However, exploring other metals in similar Fenton-like reactions has been relatively limited. FeCo alloy nanoparticles (NPs), anchored on nitrogen-doped mesoporous carbon spheres (FeCo/NMCS), have been effectively synthesized and used as a Fenton-like catalyst in wastewater treatment under alkaline conditions. The NMCS exhibited spherical with an average diameter of 488.1 nm, while the FeCo alloy NPs, uniformly distributed over the NMCS, had an average diameter of 8.2 nm. The mesopores served as anchoring points for the NiCo alloy NPs, effectively preventing their possible agglomeration. The NMCS was composed of 3.91 wt% nitrogen. With 30 mg of FeCo/NMCS and 25 mM H2O2, more than 92% of tetracycline hydrochloride (TC) was degraded within 35 min at pH levels 7, 9, and 11. The remarkable degradation rate was attributed to the dual active sites present in the FeCo alloys. The rapid degradation of TC, even at pH 11, indicates the potential of FeCo/NMCS as a valuable solution for wastewater treatment under alkaline conditions. Industrial reactive (Y145, R195, B222A) and disperse dyes (O30, R167, B79) with a concentration of 10 ppm were degraded within 20 min when using 10 mg of the FeCo/NMCS catalyst and 25 mM H2O2 at pH 9. After five consecutive TC degradation cycles at pH 7 and 9, the FeCo/NMCS demonstrated consistent performance, emphasizing its reusability. FeCo/NMCS provides a promising solution to pollution control and wastewater treatment with stability, superior catalytic activity, magnetic separability, and recyclability.

Aerogel-derived carbon quantum dots modified BiOCl nanocomposites with augmented oxygen vacancies for enhanced photodegradation of antibiotics

Composite carbon quantum dots (CQDs), characterize as zero-dimensional carbon nanomaterial, play a crucial role in accelerating the separation of photoelectron-hole pairs within photocatalysts. Moreover, they introduce abundant oxygen vacancies (OVs) and facilitate the formation of new defect levels. Therefore, in this study, CA/BiOCl-x was synthesized via the hydrothermal method using carbon aerogel (CA) as the precursor for CQDs endowed with visible light activity. Through the degradation of tetracycline hydrochloride (TCH), the results demonstrate that CA/BiOCl-6 % exhibits the most prominent photocatalytic efficiency, showcasing a degradation rate of TCH under visible light irradiation fourfold higher than that of pristine BiOCl. Furthermore, the degradation activity is significantly enhanced under full spectrum irradiation, achieving a degradation rate of ∼100 %. The observation indicated efficient integration of CQDs into BiOCl through C = O, introducing abundant OVs. Electrochemical analysis revealed that the enhancement of catalyst recombination significantly augmented both the lifetime of photogenerated carriers and the intensity of photocurrent. Active species quenching experiments indicated the superior role of superoxide radical (•O2−) in CA/BiOCl mediated TCH degradation. Liquid chromatography-mass spectrometry further confirmed the degradation pathways of contaminants. This study provides novel insights into the development of efficient photocatalysts for remediations of organic pollutants.

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.

Synthesis of Cu2+-doped magnetic ZnFe2O4 for catalyzing PMS to remove tetracycline hydrochloride

To address the limited catalytic activity of ZnFe2O4 in advanced oxidation process (AOP), Cu2+-doped ZnFe2O4 (Cu0.1Zn0.9Fe2O4) was synthesized using a simple one-pot hydrothermal method. Comprehensive characterization tests indicated that Cu2+ ions were doped into the lattice of ZnFe2O4 without changing the crystal structure. The introduction of Cu2+ ions made the sample highly ferromagnetic, with a specific magnetization of 25.7 emu/g. Cu0.1Zn0.9Fe2O4 was employed to catalyze the degradation of tetracycline hydrochloride (TCH). Systematic experiments indicate that the highest TCH removal reached 96.12 %, which was 40 % higher than that of ZnFe2O4. Coexisting inorganic anions in solution had very limited impact on the catalytic performance of Cu0.1Zn0.9Fe2O4. And after 5 cycles, the removal rate of TCH remained 71.06 %. ROS quenching tests suggest that 1O2 and O2·- played a dominant role in the AOP reaction.