Oxidation Of Amoxicillin Research Articles

OXIDATIVE DESTRUCTION OF AMOXICILLIN IN PHOTO-FENTON-LIKE OXIDIZING SYSTEM USING SOLAR IRRADIATION

The kinetic regularities of oxidative destruction of β-lactam penicillin antibiotics are studied using amoxicillin as example in Fenton-like iron-persulfate system under solar irradiation. The effect of Fe2+ and persulfate concentrations on the antibiotic degradation rate and mineralization in terms of total organic carbon (TOC) decay in combined {Solar/Fe2+ /S2O82-} system was examined. With the increase of oxidant concentration from 0.5 mM to 1.5 mM, the initial reaction rate of amoxicillin degradation increased to 2.5-fold, and the conversion of target compound and TOC mineralization reached 90% and 19%, respectively, after 120 min of solar exposure. Increasing the Fe2+ concentration from 0.1 mM to 0.3 mM resulted in a 1.5-fold increase in the initial reaction rate of amoxicillin oxidation and up to 21% for TOC mineralization. A comparative evaluation of different oxidizing systems was given. It was experimentally established that the efficiency of amoxicillin destruction process increases in the order: {S2O82-} < {Solar} < {Solar/S2O82-} < {Fe2+/S2O82-} < < {Solar/Fe2+/S2O82-}. It should be noted that TOC mineralization was observed only in combined {Solar/Fe2+/S2O82-} system, which indicates to deep oxidation of intermediates and, consequently, increasing biodegradability of the final reaction products. It was found that in the real water matrix, in the natural surface water of Selenga River, inhibition of amoxicillin degradation and TOC mineralization were observed, due to a greater extent to bicarbonate ions presented in it. The obtained results demonstrate the prospect of using solar irradiation for effective degradation of β-lactam penicillin antibiotics in the combined {Solar/Fe2+/S2O82-} oxidation system. For citation: Alekseev K.D., Sizykh M.R., Batoeva A.A. Oxidative destruction of amoxicillin in photo-fenton-like oxidizing system using solar irradiation. ChemChemTech [Izv. Vyssh. Uchebn. Zaved. Khim. Khim. Tekhnol.]. 2024. V. 67. N 12. P. 123-130. DOI: 10.6060/ivkkt.20246712.7082.

Degradation of Amoxicillin in Water by Fenton, Photo-fenton and Photocatalysis Using Copper Oxide

In recent years, the presence of drug residues in water has become a major environmental issue. Among these pollutants is amoxicillin. Our aim is to propose effective methods for decontaminating wastewater containing amoxicillin. This study was carried out using the chemical oxygen demand method. This work has shown that hydroxyl radicals can effectively degrade amoxicillin. The rate of hydroxyl radical production from hydrogen peroxide and iron (II) ions increases in the presence of sunlight. Amoxicillin oxidation is optimal at a pH of 3 and a [H2O2]/[Fe2+] ratio of 13.33. Amoxicillin degradation is faster at low concentrations than at high concentrations. The oxidation of amoxicillin by photo-Fenton results in degradation rates of up to 99%. A study of the adsorption of amoxicillin on copper oxides showed that amoxicillin adsorbs weakly to the amoxicillin surface, with an adsorption rate of 17%. However, in the presence of amoxicillin, hydrogen peroxide and sunlight, degradation rates of up to 99% were obtained. This work has shown that the degradation of amoxicillin is better with solar photo Fenton and solar photocatalysis in the presence of copper oxide than with the Fenton process.

Nickel-doped tungsten fabricated electrode for electrochemical sensing of amoxicillin

One of the most popular antibiotics used in human medicine is amoxicillin (AML). It is frequently applied to humans and animals to avoid or treat infections caused by bacteria. However, considering its widespread application and excessive use of AML, it could harm the environment and the general world because of the hazardous potential of its pharmaceutical industry effluents. Additionally, some unpleasant compounds might be left behind due to the extensive use of these animals in food production. Hence, AML may be the root cause of several illnesses, including rashes, nausea, vomiting, and colitis linked to antibiotics, if it is present in biological fluids in sufficient quantities. Aquatic habitats where it accumulates can give rise to bacterial species that are susceptible to it. Novel electroanalytical methods with sensitive and quick examination abilities are required to identify and quantify the level of AML in drugs, biological fluids, environmental pollutants, and foods. We have developed a novel sensor that quantitatively detects AML using a modified carbon paste electrode containing nickel-doped tungsten oxide (Ni-WO3). Findings show that Ni-WO3 acts as an electrocatalyst in the oxidation of AML. AML-wide concentration showed a strong linear response from this electrocatalytic oxidation encompassing the range of 0.05 μM to 0.9 μMwith a low detection limit of 8.68 × 10−9 M. As a result, the current electrocatalytic method provides a quick, accurate, and simple method to detect AML in biological medium and pharmaceutical formulations. A sensor with excellent reproducibility, short response times, and outstanding stability has been described as the modified electrode.

Synthesis of Tin/Tin Oxide (Sn-SnO2) Microparticles Scattered on Natural Phosphate and Its Utilization in Capturing Amoxicillin Antibiotic in Real Water Samples

Microparticles of tin and tin oxide scattered on natural phosphate (Sn-SnO2)-NPh were thermally prepared and then used as a modifier of a graphite electrode for amoxicillin (AMX) detection using DPV. It was characterized by FTIR, SEM and XRD. The Sn formation was confirmed by the appearance of their corresponding peaks in the XRD pattern. In addition, the transformation of Sn into SnO2 and Ca(SnO4) and SnF4 as a function of temperature was observed. The charge transfers resistance (Rct) value of the (Sn-SnO2)-NPh-CPE is 71.07 Ω, indicating a higher electron transfer capacity compared to NPh-CPE (92.32 Ω) and CPE (108.5 Ω). Also, it has an area surface high. This result indicates, the synergetic interaction between these materials structures increased the electrochemical activity. The AMX oxidation at the (Sn-SnO2)-NPh-CPE is controlled by a diffusion process with the transfer of two electrons. The quantification provided a good linear relationship in the range of AMX concentration from 7.0 × 10−7 to 1.0 × 10−5 mol l−1 with a correlation coefficient of 0.982. The detection limit was calculated as 1.89 × 10−7 mol l−1. Satisfactory results were obtained from the detection of the AMX in different samples using the prepared electrode.

Induced S-scheme CoMn-LDH/C-MgO for advanced oxidation of amoxicillin under visible light

The development of low-cost photostable heterostructures with robust interfacial contact is critical for competent photoactivity and practical applications. The solid-state approach was successfully employed for fabrication of novel stacked oval-shaped CoMn-LDH/C-MgO composites with Mn-O-Mg bridges for efficient interfacial charge separation induced by S-scheme charge transfer for degradation of amoxicillin (AMX). The persulfate (PS) activation mechanism was confirmed by Raman analysis using bond length relationship to peak shifts. PS activation rate was 1.8 times of CoMn-LDH/PS for the S-scheme heterojunction with a 99.97 ± 0.16 % removal efficiency after 60 min of irradiation at pH 5.2. S-scheme photocatalytic ozonation increased AMX mineralization rate by up to 8 times compared to ozonation. Antimicrobial studies confirmed bacterial growth inhibition of composites and the by-products of AMX degradation had reduced bacterial growth inhibition compared to AMX. This work demonstrated the development of an S-scheme CoMn-LDH/C-MgO heterojunction as a visible light heterogeneous photocatalyst for degradation of pharmaceuticals.

Pillared bentonite from Al-Fe-Cu polymeric precursor in solid state for the catalytic oxidation of amoxicillin

A Colombian bentonite is successfully pillared with Al, Al-Fe, Al-Cu and Al-Fe-Cu polyhydroxications in solid state. The effect of the Fe and Cu content on the physicochemical properties of the pillared bentonite was evaluated using characterization techniques such as X-ray fluorescence (XRF), X-ray diffraction (XRD) and textural analysis (nitrogen physisorption). The Box-Behnken statistical experiment design was used to determine the optimal parameters of the independent variables hydrogen peroxide (0.120–0.144 M), catalyst load (0.5–1.5 g/L) and type of catalyst (PILC FeCu1, FeCu5, FeCu10) in the catalytic oxidation (CWPO) of amoxicillin. The optimized conditions of hydrogen peroxide (0.137 M) and catalyst loading (0.7 g/L) were used to compare the catalytic performance of the catalysts with 1%, 5% and 10% Al-Fe, Al-Cu and Al-Fe-Cu reaching a removal between 91% and 100% of amoxicillin at T and ambient pressure. The rate constants determined allowed the identification of the best catalyst of each series to study the degree of mineralization and choose the best catalyst: the pillared clay with AlFeCu10, with a TOC removal of 24.6% after 2 h of reaction. After three cycles of reuse, the catalyst maintained its catalytic activity in removing amoxicillin without leaching any metal.

Photocatalytic Oxidation of Amoxicillin in CPC Reactor over 3D Printed TiO2-CNT@PETG Static Mixers

Antibiotics present common pollution in the environment, and they are often found in surface waters. Their presence or decomposition in water under natural sunlight can cause different unwanted consequences on the environment. In this paper, we report the application of 3D printed photocatalysts shaped as helix static mixers for tentative photocatalytic oxidation of antibiotic amoxicillin. The research was carried out in laboratory conditions in a semi-pilot-scale compound parabolic reactor (CPC) with static mixers made from PETG with TiO2 and MWCNT as fillers. The efficiency of 3D printed photocatalysts was evaluated in terms of amoxicillin decomposition kinetics using a pseudo-first-order kinetic model. The experimental results of amoxicillin decomposition and generated by-products were analyzed by using the Q-TOF LC/MS technique and presented using MassHunter Workstation.

Synthesis of a novel diaquabis(1,10-phenanthroline)copper(II)chloride complex and its voltammetric application for detection of amoxicillin in pharmaceutical and biological samples

A one step facile synthesis of the novel diaquabis(1,10-phenanthroline)copper(II)chloride (A2P2CuC) complex is demonstrated. Cyclic voltammetric and electrochemical impedance spectroscopic results revealed potentiodynamic deposition of a conductive electroactive poly(A2P2CuC) film on the glassy carbon electrode surface increasing its effective surface area. In contrast to the unmodified glassy carbon electrode, appearance of an oxidative peak at a reduced potential with over two fold current for amoxicillin at poly(A2P2CuC)/GCE demonstrated its electrocatalytic property attributed to reduce charge transfer resistance and the improved surface area of the electrode surface. Better correlation of the oxidative peak current with square root of scan rate (R2 = 0.99779) than with scan rate (R2 = 0.96953) supplemented by slope of 0.58 for log(current) versus log(scan rate) confirmed diffusion controlled irreversible oxidation of amoxicillin. At optimized solution and SWV parameters, current response of poly(A2P2CuC)/GCE showed linear dependence on concentration of amoxicillin (2.0–100.0 μM) with LoD 0.0115 μM. While no amoxicillin was detected in the human blood serum sample, an amount 89.40–100.55% of the nominal level was detected in the analyzed eight tablet brands. Spike recovery in tablet samples (98.90–101.95%) and blood serum sample (102.20–101.37%); interference with an error (%RSD) of 0.00–4.51% in tablet and 0.00–2.10% in serum samples; excellent stability and reproducible results, added with the wide dynamic range and low LoD validated the method for amoxicillin determination in pharmaceutical formulations and human urine samples.

Platinum and Cobalt hydroxide – modified Platinum Electrode as Sensor for Electrochemical Oxidation of Amoxicillin

Antibiotics have recently gained in popularity due to their usage in medical treatment and the process of removing them from the environment. Amoxicillin is one of the antibiotics that constitutes the study's subject. On a Pt disc electrode and a cobalt hydroxide modified-Pt electrode, the scan rate and pH in the electrochemical oxidation of amoxicillin were investigated. The voltammetry measurement's current peak revealed that changing the electrode surface could increase the electrochemical response and sensitivity of the working electrodes. The Pt/Co(OH)2 modification working electrode had a high sensitivity in the electro-oxidation determination of amoxicillin, with a linear range of the sensor of 20 to 80 M and a limit of detection of 7.15 M for the Pt disc electrode and 3.64 M for the cobalt hydroxide modified Pt electrode. The findings of determination in real samples with electro-oxidation using a modified electrode were in good agreement with a confidence level of 95 percent, according to the comparing method with HPLC.

Synthesis of ZnO nanoparticles on carbon graphite and its application as a highly efficient electrochemical nano-sensor for the detection of amoxicillin:analytical application: milk, human urine, and tap water

Amoxicillin is an antimicrobial of the penicillin class discovered in 1928. The objective of this paper is to construct a simple platform for electrocatalytic detection of amoxicillin using a ZnO@CPE nano-sensor constructed using simple and inexpensive processes using hydrothermal methods. Our results show that the constructed ZnO@CPE electrode exhibits excellent electrocatalytic activity compared to the unmodified electrode, with consistent, reproducible, and stable behavior. The electrochemical behavior of the amoxicillin oxidation reaction is diffusion controlled and fully reversible. The effect of the pH of the phosphate buffer solution on the antibacterial behavior of amoxicillin shows that the number of protons and electrons were equal. The morphology and chemical composition of the constructed nanoparticles were characterized by scanning electron microscope, transmission electron microscope, high-resolution transmission electron microscope, X-ray diffractometer, and infrared spectroscopy. Suggest the formation of zinc oxide nanocrystals on the carbon sheets with an order size of 22.957 nm. The diffusion coefficient and catalytic rate constant were 1.135 × 10–4 cm2/s and 8.314 × 103 mol.l−1/s, respectively. The proposed nano-sensor demonstrated a wide linearity range from 10–4 M to 10–6 M with LOD = 1.21 × 10–7 M and LOQ = 3.32 × 10–7 M according to the square-wave voltammetry method. The ZnO@CPE nano-sensor was examined for the detection of amoxicillin in real samples. Schematic concept of amoxicillin detection on the electrocatalytic surface of the nano-sensor fabricated with ZnO@CPE.

Complexation of amoxicillin by transition metals: Physico-chemical and antibacterial activity evaluation

Some bacteria have developed resistance to antibiotics that were once commonly used to treat them. Moreover, this resistance has become more and more massive and worrying. During this work, we succeeded in synthesizing “metal-antibiotic” complexes, combining as a ligand for the metals of Cu (II), Zn (II) and Fe (III). These complexes AMX − M (M = Cu, Fe and Zn) were characterized by UV–Vis spectrophotometry, IR spectroscopy, and electrochemical methods. Job’s method of continuous variation suggested 1:1 metals to ligand stoichiometry for all amoxicillin complexes. The binding constant/association constant (K) of the AMX with Zn(II), Cu(II), and Fe(III) were found to be 4.46 × 104, 7.17 × 102 and 7.65 × 102 L mol−1, respectively. The IR spectra shows that the ligands coordinated to the metal ions through amino, imino, carboxylate, β-lactamic and carbonyl groups. The electrochemical results proved that amoxicillin oxidation process can be delayed by transition metal complexation. After, the complex synthesis, the antibacterial activity of ligand and its metal complexes were evaluated against Escherichia. coli bacteria by antibiogram method. The results show that the metal-amoxicillin complexes have better antibacterial activity against Escherichia coli (E. coli) than the free ligand (amoxicillin) due to the AMX protection against oxidation after complexation.

Synthesis, characterization, and electropolymerization of a novel Cu(II) complex based on 1,10-phenanthroline for electrochemical determination of amoxicillin in pharmaceutical tablet formulations

UV–Vis and FT-IR results confirmed synthesis of a novel complex, aquachlorobis(1,10-phenanthroline)copper(II) iodidemonohydrate (ACP2CuIH), following a simple ion exchange reaction. CV and EIS results of potentiodynamically fabricated novel poly(ACP2CuIH)/GCE revealed modification of the electrode surface by a conductive, and electroactive polymer film leading to an increased effective electrode surface area. In contrast to the unmodified electrode, appearance of an irreversible oxidative peak at much reduced potential with five folds current enhancement at poly(ACP2CuIH)/GCE showed catalytic effect of the modifier towards oxidation of amoxicillin (AMX). DPV current response of poly(ACP2CuIH)/GCE showed linear dependence on concentration of AMX in the range 5 × 10−7 - 1.0 × 10−4 M with LOD and LOQ of 1.3 × 10−8, and 4.6 × 10−8 M, respectively. The AMX level in selected four tablet brands were in the range 95.2–101.8% of their nominal values. Spike recovery results of 98.8–100.6%, interference recovery results with less than 4.5%error, lower LOD and wider dynamic range than most of the previously reported methods validated the potential applicability of the present method based on the novel poly(ACP2CuIH)/GCE for determination of AMX in real samples with complex matrix.

Electrochemical Degradation of Amoxicillin on a Ti/Ta2O5/Pt-RuO2-IrO22 Electrode

This work deals with the degradation of Amoxcillin which is one of the antibiotics commonly used in human and veterinary medicine. For such an investigation, Pt-RuO2-IrO2 (PRI) electrode was used as anode and various parameters such as current density (20 - 100 mA/cm2), supporting electrolyte and chloride were monitored. The results showed that the amoxicillin oxidation reaction is diffusion controlled and its degradation rate increases as the applied current increases. The degradation of amoxicillin on the PRI electrode, in the absence of chloride, is very low with less than 10% of the COD abatement rate. But, in the presence of chloride, the degradation of the Amoxicillin on PRI electrode leads to its mineralization. During electrolysis, chloride was oxidized into chlorine under the form HClO at pH - at pH > 8 that contribute to a significant degradation of the Amoxicillin. The amoxicillin removal rate goes from 0.83% to 73.8% in the absence and in the presence of Cl-, respectively after 10 h of electrolysis. In addition, the degradation kinetic of amoxicillin in HClO4 is 10 times faster than in KClO4 and follows pseudo first-order reaction.

Carbon nanofibers supported Co/Ag bimetallic nanoparticles for heterogeneous activation of peroxymonosulfate and efficient oxidation of amoxicillin

The carbon nanofibers supported Co/Ag bimetallic nanoparticles (Co@CNFs-Ag) were synthesized for heterogeneous activation of peroxymonosulfate and efficient oxidation of amoxicillin in this work. Co nanoparticles with a diameter of 20–30 nm were encapsulated in the carbon nanofibers to reduce the loss of Co during the preparation and catalysis processes. Ag nanoparticles (5–10 nm) were distributed on the surface of CNFs. Complete removal of amoxicillin could be achieved within 30 min by Co@CNFs-Ag activated peroxymonosulfate system. The high catalytic performance could be attributed to the large aspect ratio (> 10,000) of the carbon nanofibers and the mutual reaction of the Co/Ag bimetallic nanoparticles with peroxymonosulfate. The optimal mass ratio of oxidant and catalyst was 10 and the optimized pH was 7. Co@CNFs-Ag exhibited stable catalytic activity and minimal metal leakage over a period of 5 cycles. The activation energy of the system was 29.51 kJ/mol derived by the Arrhenius equation. Both hydroxyl and sulfate radicals contributed to amoxicillin degradation and the latter were key to the degradation. Finally, the reaction mechanism of bimetallic synergistic catalytic system and possible amoxicillin degradation pathways were elucidated. The results of this study provide novel insights for application of sulfate radical-based advanced oxidation processes in environmental remediation.

Application of response surface methodology in electrochemical degradation of amoxicillin with Cu-PbO2 electrode: Optimization and mechanism

In this study, Cu doped PbO2 electrode was prepared by electrodeposition and used for electrochemical oxidation degradation of amoxicillin (AMX), which showed that the effect of Cu doped PbO2 electrode was better than that of undoped PbO2 electrode in degrading amoxicillin. An optimized model was setup with the help of response surface method (RSM). The optimal values of experimental parameters and the interactions between the parameters were explored, including current density, pH and initial AMX concentration. The combustion efficiency was calculated in the electrochemical oxidation of amoxicillin in aqueous solution and the enhancement was found with Cu doped PbO2 electrode. The enhanced mechanism with Cu doped PbO2 electrode was discussed based on the analysis of hydroxyl radicals and the combustion efficiency. The mechanism of amoxicillin degradation was discussed. This paper can provide basic data and technique reference for amoxicillin pollution control.

Fly ash as photo-Fenton catalyst for the degradation of amoxicillin

Fly ash, a coal combustion residue from a thermoelectric company in Colombia, has been used as heterogeneous catalyst in a photo-Fenton process to eliminate amoxicillin. The fly ash was characterized by X-ray diffraction, Scanning and Transmission Electron Microscopies, X-ray Fluorescence and Infrared Spectroscopies, Thermal analyses, particle size distribution and N2 physisorption. The photocatalyst was a complex mixture including Fe2O3 (9.37%) and TiO2 (1.08%). This catalyst showed very good catalytic performance in the Photo-Fenton oxidation of amoxicillin, with degradation degrees as high as 36%. A preliminary study of degradation by-products was carried out by means of mass spectrometry.

Sulfate radicals mediated oxidation of amoxicillin: Optimization of key parameters

The lack of selectivity of hydroxyl radical species used in Advanced Oxidation Processes (AOPs) to eliminate organic pollutants has swayed the investigation towards more selective oxidizing agents. In the current work, we investigated the oxidation of amoxicillin, the most commonly used antibiotic worldwide, by sulfate radical species generated from the activation of Persulfate (PS) and Peroxymonosulfate (PMS-Oxone®). The optimization of this oxidation using the box-behnken experimental design was conducted. From this study, it was shown that the PS/Fe2+ mixture was capable of dose-dependently inducing a significant amount of degradation of the Amoxicillin compound with a higher degradation rate detected with higher amounts of PS and Fe2+. Sulfate radicals generated from the “Oxidant-Catalyst” mixture were shown to be the predominant oxidizing species involved in this process with the second order rate constant of Amoxicillin degradation found to be equal to 2.79 × 109 M−1. S−1. In the optimization procedure, the box-benhken methodology allowed us to assess the impact of various factors and their interaction on COD removal efficiency (mineralization rate), which is the objective response needed to be optimized. The variables considered were PS as the oxidant, Fe2+ as the catalyst, and pH. It was concluded that among the various parameters tested, pH was the most influential as a decrease in pH values was shown to be positively correlated with a significant increase in COD removal rate. Hence, the highest mineralization rate of Amoxicillin (≈76.10% COD removal) was achieved with PS = 300 μM, Fe2+ = 250 μM, and a pH value of 3.

Ternary CdS-MoS2 coated ZnO nanobrush photoelectrode for one-dimensional acceleration of charge separation upon visible light illumination

Ternary CdS-MoS2 coated ZnO nanobrush photoelectrode from chemical bath deposition was successfully fabricated on a FTO substrate for photocatalytic degradation of amoxicillin. The vertically grown ZnO core on FTO substrates provided a direct pathway for electron transfer; while the well-crystallized CdS/MoS2 shell offered effective visible light absorption and increased active sites. Prolonged lifetime of charge carriers was demonstrated by transient photovoltage (TPV) measurement. The ternary brush-type electrode exhibited enhanced photoelectrochemical performance with a photocurrent density of 20.32 mA/cm2 at 0 V vs. Ag/AgCl under visible light illumination (λ ≧ 420 nm), which was 5.2 times, 1.8 times and 3.6 times of that of pristine CdS, CdS-MoS2 film and ZnO/CdS nanobrush, respectively. The improved photoelectrochemical activity was ascribed to the enhancement of light absorption, appropriate band alignment and prolonged charge carriers’ lifetime. The ZnO/CdS-MoS2 nanobrush film degraded 94% of amoxicillin in 60 min, exhibiting promising photocatalytic activity under visible light illumination (λ ≧ 420 nm). The reusability and stability of the electrode were evaluated by recycling experiments. The intermediates of amoxicillin oxidation were also identified and the degradation pathway was proposed.

Cyclic Voltammetry Study of Mediated Electrochemical Oxidation Using Platinum Wire, Pt/Co(OH)2 and Pt/Co Electrodes In Various Supporting Electrolytes

<p>Amoxicillin is one of β-lactam antibiotic in penicillin groups which their presence in surface water and wastewater not only affects water quality but also causes long-term adverse effects on ecosystems and human health due to their resistance to natural biodegradation. The processing of organic waste electrochemically has the advantage of cheap and efficient cost, exhaust gas that does not contain toxic and hazardous materials. We have studied the process of amoxicillin electro-oxidation mediated by a cobalt (III) ion called an electrochemical oxidation process mediated (MEO) in a voltammetry study using a platinum working electrode, Pt/Co(OH)<sub>2</sub> and Pt/Co in various supporting electrolytes such as KNO<sub>3</sub>, NaClO<sub>4</sub>, Na<sub>2</sub>SO<sub>4</sub> and phosphate buffer solution with concentrations 0.10 M. The results show that the amoxicillin oxidation peaks using the above-mentioned working electrode in various electrolyte solutions are in the potential range of 500-670 mV (Ag/AgCl). The presence of cobalt ions forming complex compounds with amoxicillin causes the oxidation current decreasing that indicates the presence of degradation to amoxicillin.</p>

Photoelectrocatalytic degradation of amoxicillin over quaternary ZnO/ZnSe/CdSe/MoS2 hierarchical nanorods

Quaternary semiconductor film consists of ZnO, ZnSe, CdSe and MoS2 was designed to establish a core-shell structure to achieve the photoelectrochemical oxidation of amoxicillin. The hybrid photoelectrode was fabricated on a FTO substrate from bath deposition methods. The hierarchical ZnSe/CdSe/MoS2 shell was covered uniformly on ZnO nanorod core which provided a direct pathway for electron transfer, large surface area to enhance light absorption and increase active sites. The quaternary photoelectrode exhibited a photocurrent density of 26.86 mA/cm2 at 0 V vs. Ag/AgCl under UV–visible light illumination, which was 31.9 times, 16.7 times and 1.6 times of that of the bare ZnO nanorods, binary ZnO/ZnSe and ternary ZnO/ZnSe/CdSe photoelectrodes, respectively. 10 ppm of amoxicillin was completely degraded in 30 min by the quaternary working electrode with an applied bias of 0.5 V vs. Ag/AgCl. The reusability and stability of quaternary electrode was demonstrated by 3-run recycling experiments. The enhanced photoelectrochemical performance of quaternary photoelectrode can be attributed to the enhancement of light absorption and increased active sites from the coverage of visible-active layers, the accelerated charge separation from the formation of p-n junction and reduced photocorrosion of CdSe from the protection of MoS2 on the surface.