Photocatalytic Degradation Of Amoxicillin Research Articles

Peripherally tetra-substituted zinc (II) phthalocyanine sensitized TiO2 composite: Monitoring with tandem LC/MS and photocatalytic degradation of amoxicillin

In this study, zinc phthalocyanine (ZnPc)/TiO2 photocatalysts were obtained by sol-gel method using titanium isopropoxide and ZnPc as Ti source, and dye pigments, respectively. The synthesized (ZnPc)/TiO2 photocomposites were characterized by scanning electron microscopy/energy dispersive X-ray analyzer (SEM/EDX), X-ray diffraction (XRD) analysis, Fourier transform infrared spectroscopy (FTIR), and Ultraviolet–Visible Diffuse Reflectance Spectroscopy (UV-DRS). Photodegradation tests were evaluated in the ultraviolet and visible light range with photocatalysts to compare photocatalytic activity and investigate optimum mineralization of amoxicillin (AMX) by monitoring the triple quadrupole LC/MS-MS (Tandem MS2). Mineralization of AMX was also investigated by total organic carbon (TOC) analysis, suggesting that either amoxicillin itself or its resistant metabolites are still in solution and mineralization did not occur in an expected manner.

Photocatalytic degradation of amoxicillin using TM doped ZnO nanoparticles synthesized from orange peel extract

The present work investigates the degradation of Amoxicillin using ZnO and Fe, Ni, Co doped ZnO nanoparticles synthesized using orange peel extract. The synthesized catalysts were characterised with the help of X-ray diffraction, scanning electron microscopy, UV–Visible and photoluminescence spectroscopy for structural and optical properties and the study of charge transport behaviour of the catalysts. The observed results indicate that the Ni doped ZnO nanoparticles exhibit superior degradation efficiencies of 80.71% and 86.21% under UV light and UV + visible light irradiation. Moreover, the slightly basic environment was found to be favourable for optimizing the degradation efficiency of the catalyst, as confirmed by the pH variation experiment. The scavenging experiments were utilized to reveal the most prominent role of hydroxyl radicals in the degradation of Amoxicillin. Additionally, a mere 10.97% reduction in degradation efficiency was observed after fours cycles of degradation experiment. The plausible pathway of amoxicillin degradation has been included into this study as well. Hence, the transition metal (TM) doped ZnO nanoparticles synthesized through waste orange peels suggest their utilization as efficient photo catalyst in Amoxicillin degradation.

Enhanced photocatalytic degradation of amoxicillin using a spinning disc photocatalytic reactor (SDPR) with a novel Fe3O4@void@CuO/ZnO yolk-shell thin film nanostructure

Antibiotics are resistant compounds with low biological degradation that generally cannot be removed by conventional wastewater treatment processes. The use of yolk-shell nanostructures in spinning disc photocatalytic reactor (SDPR) enhances the removal efficiency due to their high surface-to-volume ratio and increased interaction between catalyst particles and reactants. The purpose of this study is to investigate the SDPR equipped to Fe3O4@void@CuO/ZnO yolk-shell thin film nanostructure (FCZ YS) in the presence of visible light illumination in the photocatalytic degradation of amoxicillin (AMX) from aqueous solutions. Stober, co-precipitation, and self-transformation methods were used for the synthesis of FCZ YS thin film nanostructure and the physical and chemical characteristics of the catalyst were analyzed by XRD, VSM,, EDX, FESEM, TEM, AFM, BET, contact angle (CA), and DRS. Then, the effect of different parameters including pH (3–11), initial concentration of AMX (10–50 mg/L), flow rate (10–25 mL/s) and rotational speed (100–400 rpm) at different times in the photocatalytic degradation of AMX were studied. The obtained results indicated that the highest degradation efficiency of 97.6% and constant reaction rate of AMX were obtained under LED visible light illumination and optimal conditions of pH = 5, initial AMX concentration of 30 mg/L, solution flow rate of 15 mL/s, rotational speed of 300 rpm and illumination time of 80 min. The durability and reusability of the nanostructure were tested, that after 5 runs had a suitable degradation rate. Considering the appropriate efficiency of amoxicillin degradation by FCZ YS nanostructure, the use of Fe3O4@void@CuO/ZnO thin film in SDPR is suggested in water and wastewater treatment processes.

Multifunctional metal (Ag, Bi)-organic frameworks: a versatile platform for photocatalytic degradation, CO2 and N2 reduction, and enhanced antibacterial applications

The facile synthesis of a bimetallic-organic framework is successfully established to portray an efficient catalyst in photocatalytic degradation and photoreduction of nitrogen (N2) and carbon dioxide (CO2) and with antibacterial properties. In the current study, a novel B-BTC (where B represents Ag and Bi) organic framework was successfully synthesized and opted for advanced characterizations. The high-resolution transmission electron microscopy and X-ray photon spectroscopy illustrate the heterostructure formation, whereas X-ray diffraction spectroscopy, zeta sizer, and zeta potential were used to reveal the crystallinity, polydispersity, and average size of the nanomaterial. The material was characterized for photoluminescence analysis to understand the recombination rate and has been compared with the Bi-organic framework. B-BTC was further opted to determine the photocatalytic efficacy, through photocatalytic degradation of amoxicillin (AMX), photocatalytic reduction of N2 to ammonia (NH3), photoreduction of CO2, and antibacterial disinfection. The catalyst showcased ∼90% degradation of AMX under light-emitting diode light irradiation for 60 min. Successful photoreduction of N2 and CO2 showcases a fair generation of NH3 and value-added hydrocarbons, respectively. For each photocatalytic application, a mechanism has been knitted for understanding the overall reactions concerning the proposed reactions. Interestingly, the catalyst also showcased excellent antibacterial activity toward Escherichia coli and Staphylococcus aureus, with a proposed mechanism.

Visible light responsive AgBiS2 nanomaterials for photocatalytic applications in removal of antimicrobial compounds and bacterial pathogens: Possible electrochemical pathways

Potential synthesis of ternary chalcogenide nanocomposite to showcase a practical electronic pathway to improve photocatalytic efficiency was carried out. In the present study, AgBiS2 nanorod-shaped with remarkably visible-light absorption was prepared using solvothermal techniques. This material was employed in photocatalytic degradation of amoxicillin (AMX) under visible light irradiation. The results indicated more than 90% degradation of AMX under 60 min having a corresponding bandgap of ∼2.19 eV. In the verge of understanding the photogenerated separation of electron-hole pair, VB and CB potentials were calculated to be 2.06 eV and − 0.76 eV, proposing a possible pathway for the degradation study. The photogenerated intermediates were identified using LC-MS analysis and the mineralization was followed using TOC analysis. A scavenging experiment showed a potential reactive oxygen species involved in the oxidation of organics that proved effective in three consecutive trials.In addition, antibacterial and antibiofilm activity showcased fair efficiency of the material, especially the presence of Ag+ in AgBiS2 improves antimicrobial activity. In case of antibiofim activity, 4 × 107 CFU/mL were seen to be most effective for the biomass formation of the biofilms.

Enhanced photocatalytic activity and antiviral evaluation of CuO@Fe2O3 NC for amoxicillin degradation and SARS-CoV-2 treatment.

Copper oxide nanoparticles (CuO NPs) and CuO NPs decorated with hematite (Fe2O3) nanocomposites (CuO@Fe2O3 NC) were biosynthesized by a green method using Portulaca oleracea leaves extract. The NC were characterized using various techniques, including X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), and UV-Vis spectroscopy. The results showed that the synthesized CuO and CuO@Fe2O3 NC were crystalline with a monoclinic crystal structure and contained functional groups responsible for catalytic activity. The size of the nanocomposites ranged from 39.5 to 45.9 nm, and they exhibited a variety of agglomerated or aggregated shapes. The CuO@Fe2O3 NC showed improved photocatalytic activity for the degradation of antibiotics in water and wastewater and promising antiviral activity against SARS-CoV-2, indicating its potential for use in disinfection applications. The study investigated the impact of irradiation time on the photocatalytic degradation of Amoxicillin and found that increasing the irradiation time led to a higher degradation rate. The band gap energy (Eg) for pure CuO NPs was around 2.4 eV and dropped to 1.6 eV with CuO@Fe2O3 NC. In summary, the CuO@Fe2O3 NC has the potential to be an efficient photocatalyst and promising antiviral agent for environmental remediation. The CuO@Fe2O3 nanocomposites have been found to possess a high degree of efficacy in inactivating SARS-CoV-2 infectivity. The results of the study indicate that the nanocomposites exhibit potent anti-viral properties and hold significant potential for use in mitigating the spread of the virus.

Static adsorption and photocatalytic degradation of amoxicillin using titanium dioxide/hydroxyapatite nanoparticles based on sea scallop shells.

The objective of this study is to investigate the efficiency of two processes for the amoxicillin removal through static (batch) adsorption and photocatalytic degradation onto the prepared samples. Three solid materials as photocatalyst and/or adsorbent were synthesized viz. nanotitanium dioxide (NT) prepared by the sol-gel method, scallop shells-based nanohydroxyapatite (NP), and nanotitanium dioxide/nanohydroxyapatite composite (NTP). The physicochemical and morphological properties of the prepared samples were tested by TGA, XRD, DRS, ATR-FTIR, nitrogen adsorption/desorption isotherm, zeta potential, SEM, and TEM. The major operational conditions were optimized for catalyst or adsorbent mass, pH, shaking time, initial amoxicillin (AMX) concentration, power of UV lamp, and temperature. The results illuminated that NTP achieved the highest adsorption capacity (88.46mg/g) at 20 ℃ and AMX adsorption onto all the solid materials was well applied by Langmuir, Temkin, pseudo-second order, and Elovich models. The maximum desorption percent (98%) was attained by acetone. The degradation percent of AMX reached 85.3 and 99.5% for NT and NTP, respectively, using 0.9g/L of catalyst dosage through 90min. AMX photodegradation onto the catalysts' surface was well fitted by Langmuir-Hinshelwood, Arrhenius, and Eyring-Polanyi models with endothermic, physical, and nonspontaneous nature of photocatalysis process. NTP acts as a promising adsorbent and photocatalyst for the antibiotics' removal in wastewater.

The application of a new recyclable photocatalyst γ-Fe2O3@SiO2@ZIF8-Ag in the photocatalytic degradation of amoxicillin in aqueous solutions.

This pilot study synthesized the γ-Fe2O3@SiO2@ZIF8-Ag nanocomposites via the hydrothermal method to study its potential use in amoxicillin degradation as a novel photocatalyst in aqueous solutions under visible light radiation. Various diagnostic methods were used to determine the morphology and functional structure of the photocatalyst, and the results confirmed its proper formation. Complete degradation of AMX was obtained at a pH of 5, catalyst dosage of 0.4g/L, AMX concentration of 10mg/L, and reaction time of 60min. The efficiency of the degradation was diminished when anions were present in the reaction medium, and the order of their effect was SO42-< Cl- < NO3-< HCO3-. Biodegradability (BOD5/COD ratio) increased from 0.20 to 0.68 after 120min of photocatalytic treatment, with a COD removal of 87.54% and a TOC removal of 74.88%. Through the experimental trapping of electrons, we found the production of reactive species, such as hydroxyl radical (•OH), superoxide (O2•-), and holes (h+), in the photocatalysis reactor and that •OH was the predominant species in AMX photodegradation. Comparative experiments emphasized that the oxidation process occurs with the adsorption of pollutants on the surface of the catalyst, and the photocatalyst has the potential to be activated by various light sources, including visible light, UV light, and sunlight, with an AMX decomposition above 88%. The synthesized particles can be recovered after five consecutive cycles with minimal reduction in the degradation rate (< 4%). γ-Fe2O3@SiO2@ZIF8-Ag can be considered a promising photocatalyst for use in AMX degradation due to its recyclability, easier activation by different light sources, and excellent mineralization.

Constructing oxygen absorption and activation sites in Ce-doped g-C3N4 photocatalyst for effective removal of amoxicillin: Performance, mechanism and degradation pathways

Accelerating oxygen absorption and activation to generate O2− efficiently is challenging toward photocatalytic removal of antibiotic pollutions for water treatment. Herein, the Ce-doped g-C3N4 photocatalysts with active sites for adsorbing and activating oxygen were prepared by a pyrolysis method. It was found that CeCN-1 exhibits excellent performance toward the photocatalytic degradation of amoxicillin (AMX), which was about 3.4 times more than that of pure g-C3N4. Both experimental and theoretical studies elucidated that the Ce-g-C3N4-x have excellent oxygen absorption and activation capacity attributed to the doping of Ce ions destroys the original sp2 hybrid mode of nitrogen and carbon in the triazine ring, and the increase of solitary electrons forms the activated site. Meanwhile, the generation of N vacancies sites not only accelerate the conversion of excitons to photogenerated carriers but also generate more O2− acting as the main active species for the AMX degradation. Additionally, the photocatalytic degradation pathway of AMX was revealed through HPLC-MS and Fukui index based theorical calculation, proving that the intermediate products degraded by AMX are non-toxic and harmless. This study disclose the superiority of constructing the O2 adsorption and activation sites for photocatalytic removal of antibiotic pollutants.

Visible-Light-Active Black TiO2 Nanoparticles with Efficient Photocatalytic Performance for Degradation of Pharmaceuticals.

Special attention has recently been paid to surface-defective titanium dioxide and black TiO2 with advanced optical, electrical, and photocatalytic properties. Synthesis of these materials for photodegradation and mineralization of persistent organic pollutants in water, especially under visible radiation, presents interest from scientific and application points of view. Chemical reduction by heating a TiO2 and NaBH4 mixture at 350 °C successfully introduced Ti3+ defects and oxygen vacancies at the surface of TiO2, with an increase in the photocatalytic degradation of amoxicillin—an antibiotic that is present in wastewater due to its intense use in human and animal medicine. Three TiO2 samples were prepared at different annealing temperatures to control the ratio between anatase and rutile and were subjected to chemical reduction. Electron paramagnetic resonance investigations showed that the formation of surface Ti3+ defects in a high concentration occurred mainly in the anatase sample annealed at 400 °C, contributing to the bandgap reduction from 3.32 eV to 2.92 eV. The reduced band gap enhances visible light absorption and the efficiency of photocatalysis. The nanoparticles of ~90 m2/g specific surface area and 12 nm average size exhibit ~100% efficiency in the degradation of amoxicillin under simulated solar irradiation compared with pristine TiO2. Mineralization of amoxicillin and by-products was over 75% after 48 h irradiation for the anatase sample, where the Ti3+ defects were present in a higher concentration at the catalyst’s surface.

Photocatalytic degradation of amoxicillin and tetracycline by template synthesized nano-structured Ce3+@TiO2 thin film catalyst

Contamination of the aquatic environment with pharmaceutical compounds is a serious environmental concern. The present investigation aims to utilize the Ce3+/TiO2 thin film catalyst to remove of potential antibiotics (amoxicillin and tetracycline) using the less harmful UV-A radiations. Reduced cerium ion-doped TiO2 is obtained by a simple one-step facile template method using polyethylene glycol as the templating agent. The synthesized catalysts Ce3+@TiO2 (non-template) and Ce3+@TiO2(T) (template) were characterized by spectroscopic methods. The XPS reaffirms the reduced Ce3+ dispersed within the titania network, and the AFM showed the surface roughness of the thin films. Detailed physicochemical analyses were conducted to deduce the degradation mechanism, and repeated use of the thin film photocatalyst showed enhanced stability. Significant mineralization of the antibiotics indicates the potential applicability of the photocatalytic catalyst. Furthermore, the presence of Ce3+ significantly restricted the recombination of electron/hole pairs in the photo-excited TiO2 semiconductor and showed enhanced photocatalytic degradation of the antibiotics proceeded predominantly through the •OH.

Trimetallic@Cyclodextrin Nanocomposite: Photocatalyst for Degradation of Amoxicillin and Catalyst for Esterification Reactions

The industry is looking for new materials which can respond to specific applications that exclusively advance materials can provide. In this context, nanoparticles and nanocomposites opened an interesting method for designing specific properties which can be modulated according to the requirements. The preparation of biomolecules supported trimetallic nanoparticles and some other derives is a good example of the complex systems that can be designed for getting exclusive properties. This study is based on the preparation of new cyclodextrin supported Fe/La/Zn trimetallic nanocomposite by the microemulsion technique. Photocatalytic degradation of amoxicillin was performed using cyclodextrin-Fe/La/Zn. 78% of amoxicillin photodegradation along 4 hours of photoirradiation was achieved. Finally, the catalytic nature of new material was explored for oxidation and esterification reactions. The present study revealed that this advanced multifunctional nanomaterial can be successfully employed for environmental remediation and catalytic activities.

Photocatalytic degradation of amoxicillin from aqueous solutions by titanium dioxide nanoparticles loaded on graphene oxide.

The photocatalytic degradation of amoxicillin (AMX) by titanium dioxide nanoparticles loaded on graphene oxide (GO/TiO2) was evaluated under UV light. Experimental results showed that key parameters such as initial pH, GO/TiO2 dosage, UV intensity, and initial AMX concentration had a significant effect on AMX degradation. Compared to the photolysis and adsorption processes, the AMX degradation efficiency was obtained to be more than 99% at conditions including pH of 6, the GO/TiO2 dosage of 0.4 g/L, the AMX concentration of 50 mg/L, and the intensity of 36 W. Trapping tests showed that all three hydroxyl radical (OH•), superoxide radical (O2•-), and hole (h+) were produced in the photocatalytic process; however, h+ plays a major role in AMX degradation. Under UV irradiation, GO/TiO2 showed excellent stability and recyclability for 4 consecutive reaction cycles. The analysis of total organic carbon (TOC) suggested that AMX could be well degraded into CO2 and H2O. The formation of NH4+, NO3-, and SO42- as a result of AMX degradation confirmed the good mineralization of AMX in the GO/TiO2/UV process. The toxicity of the inlet and outlet samples of the process has been investigated by cultivation of Escherichia coli and Streptococcus faecalis, and the results showed that the condition is suitable for the growth of organisms. The photocatalytic degradation mechanism was proposed based on trapping and comparative tests. Based on the results, the GO/TiO2/UV process can be considered as a promising technique for AMX degradation due to photocatalyst stability, high mineralization efficiency, and effluent low toxicity.

Insight into Photocatalytic Degradation of Amoxicillin by Biofabricated Granular Zinc Oxide Nanoparticle: Mechanism, Optimization and Toxicity Evaluation

Amoxicillin trihydrate (AMX) is an antibiotic drug and their metabolism in aqueous phase produce adverse effects on environmental standards and human health. Present research discloses the remediation of AMX antibiotic by photocatalytic degradation using fabricated zinc oxide nanoparticles (ZnONPs). Zinc oxide behaves as an excellent n-type semiconducting material for its high band gap (~ 3.37 eV). In this investigation, the ZnONPs were synthesized biologically using banana peels extract as both reducing and capping agent. The effects of peel extract, precursor concentration and pH on ZnONPs synthesis were investigated and optimized using response surface methodology (RSM). Moreover, the synthesised nanoparticle was characterised by UV–Vis, FESEM-EDX, TEM, XRD, dynamic light scattering (DLS) and FTIR. The characteristics properties give confirmation about the spherical shape, crystalline nature of the synthesized nanoparticle. Results revealed that over 90% of AMX can be photocatalytically degraded in 120 min irradiation under UV-B irradiation. The rate of degradation of AMX was better agreed with the pseudo-second-order kinetics. The thermodynamics of the antibiotic degradation revealed that reactions were exothermic and spontaneous nature. Additionally, effective efficacy of antibiotic residues have been tested against E. coli bacteria and poor efficiency against bacteria was recorded. Finally, it can be suggested that the ZnONPs could be an effective semiconductor towards degradation of AMX from wastewater.

Facile synthesis of cooperative mesoporous-assembled CexSr1-xFexTi1-xO3 perovskite catalysts for enhancement beta-lactam antibiotic photodegradation under visible light irradiation

Results demonstrated in this work presented the synthesis of mesoporous Ce and Fe co-modified SrTiO3 (CexSr1-xFexTi1-xO3) perovskite materials using an innovative chelate complex approach, applying a molar excess of glycerol and citric acid monohydrate as the chelating agents. The influence of different Ce and Fe dopant concentrations (0 ≤ x ≤ 0.05) on the characteristics of the SrTiO3 catalysts were systematically investigated using multi-technique. The results showed that controlled Ce and Fe contents significantly altered the physical and chemical properties of the materials. The diffractogram confirmed that all prepared samples crystallized in a typical perovskite structure of SrTiO3 without deviation in the original cubic symmetry in perovskite structure when introduced Ce and Fe in the lattice. Likewise, the microscopy verified the uniformity and particle size reduction of the catalysts with increasing doping contents. In addition, all prepared samples illustrated mesoporosity and BET surface area slightly increased with increasing the doping elements and represented smaller than pure SrTiO3 sample. The Ce atom, replacing some Sr2+ in the lattice, was represented in Ce3+ and Ce4+ valence states mixture. At the same time, Fe atoms, presenting Fe3+ and Fe4+ oxidation states, cannot be incorporated by substituting Ti4+ ions in the SrTiO3 lattice structure, only incorporated with the interstitial site, as confirmed by XPS and XANES measurements. The Ce and Fe dopants improved the absorptivity towards a longer wavelength, resulting in decreasing bandgap energy. Their photocatalytic performance towards beta-lactam antibiotic degradation under visible light irradiation using an LED source was also evaluated. The Ce0.04Sr0.96Fe0.04Ti0.96O3 sample exhibited the best photocatalytic degradation of amoxicillin (67.4%) and demonstrated more activity than the pure SrTiO3 sample about 27 times. In the end, the synergistic effect of Ce and Fe dopants to help enhance the photocatalytic activity and the recycling ability were also detailed.

Photocatalytic degradation of Amoxicillin in pharmaceutical wastewater: A potential tool to manage residual antibiotics

Abstract The present study investigates the degradation of amoxicillin (AMX) using TiO2 photocatalysis and sono-photocatalysis in aqueous solution under UV-A (365 nm) and sunlight exposure. The photocatalysis, as well as sono-photocatalysis, were coupled with H 2 O2 as well to assess the improvement in the degradation of AMX. Response surface methodology (RSM) based on three-level and four variable Box–Behnken experiment design was used to analyse​ and validate the degradation of AMX. Upon comparison of observed values with predicted, the value of the coefficient of regression (R2) was 0.87 which indicate the good fit of the model. The optimum conditions for maximum degradation (80%) of AMX were AMX - 30mg/l, TiO2 dosage - 450mg/l, H 2 O2 concentration — 150 mg/l and pH — 7.0 under UV irradiation (672 W/m2). Significant improvement in rate kinetics of degradation was observed when photocatalysis was complemented with H 2 O2 and sonication (40 KHz) under optimized condition, but the maximal removal remained almost unaffected. The method proved efficient towards degradation of AMX in real pharmaceutical wastewater with reduced reaction time for targeted level treatment. It was concluded that photocatalysis is a potential method for degradation of AMX under the set optimized conditions, and it may be adopted in-silo since photocatalysis coupled with sonication becomes energy-prohibitive for degradation of AMX.

Tungsten Trioxide (WO3)-assisted Photocatalytic Degradation of Amoxicillin by Simulated Solar Irradiation

This study investigates the photocatalytic degradation of amoxicillin (AMO) by simulated solar irradiation using WO3 as a catalyst. A three-factor-three-level Box-Behnken design (BBD) consisting of 30 experimental runs is employed with three independent variables: initial AMO concentration, catalyst dosage, and pH. The experimental results are analyzed in terms of AMO degradation and mineralization, the latter of which is measured using dissolved organic carbon (DOC). The results show that the photocatalytic degradation of AMO follows pseudo-first-order kinetics. AMO degradation efficiency and the pseudo-first-order rate constants decrease with increasing initial AMO concentration and pH and increase with increasing catalyst dosage. Though AMO degradation is almost fully complete under the experimental conditions, DOC removal is much lower; the highest DOC removal rate is 35.82% after 180 min. Using these experimental results, second-order polynomial response surface models for AMO and DOC removal are constructed. In the AMO removal model, the first-order terms are the most significant contributors to the prediction, followed by the quadratic and interaction terms. Initial AMO concentration and pH have a significant negative impact on the photocatalytic degradation of AMO, while catalyst dosage has a significant positive impact. In contrast, in the DOC removal model, the quadratic terms make the most significant contribution to the prediction and the first-order terms the least. The optimal conditions for the photocatalytic degradation of AMO are found to be an initial AMO concentration of 1.0 μM, a catalyst dosage of 0.104 g/L, and a pH of 4, under which almost complete removal of AMO is achieved (99.99%).

Photocatalytic degradation of amoxicillin using Co-doped TiO2 synthesized by reflux method and monitoring of degradation products by LC–MS/MS

Photocatalytic degradation of Amoxicillin (AMX) in aqueous solution by Co-doped TiO2 and undoped TiO2 synthesized by reflux route was investigated. The catalysts were characterized using X-ray diffractometry, FT-IR spectroscopy, UV-Vis absorption spectroscopy, scanning electron microscopy and X-ray Fluorescence Spectroscopy, and using specific surface area, particle size and zeta potential measurements. Photocatalytic efficiency of Co-doped and undoped TiO2 was compared for degradation of AMX under UV-C and visible irradiation by investigating the effects of the parameters such as percentage of the cobalt doped, amount of catalyst, irradiation time, initial AMX concentration and pH of the medium. Effects of organic and inorganic ions in the aqueous solution were also studied. Results showed that degradation of AMX is improved by Co doping to TiO2. It was detected that complete removal is achieved within 240 min of irradiation under UV-C and 300 min under visible irradiation. 94%, 21% and 16% degradation efficiencies were achieved after 300 min of photocatalysis under visible light in the presence of Co-doped TiO2, undoped TiO2 and Degussa P25 TiO2, respectively. Degradation products were determined and followed using LC–MS/MS technique to describe the evolution of AMX. An attempt was made to estimate the photocatalytic cleavage pathway of AMX by LC-MS/MS

Photocatalytic degradation of amoxicillin by carbon quantum dots modified K2Ti6O13 nanotubes: Effect of light wavelength

A novel carbon quantum dots modified potassium titanate nanotubes (CQDs/K2Ti6O13) composite photocatalyst was synthesized by hydrothermal treatment combined with calcination. X-ray diffraction (XRD) pattern and transmission electron microscopy (TEM) indicated formation of potassium titanate nanotubes and successful deposition of CQDs onto K2Ti6O13. The photocatalytic performance of CQDs/K2Ti6O13 composite was evaluated by degradation of amoxicillin (AMX) under the irradiation of visible light and lights with the wavelengths of 365, 385, 420, 450, 485, 520, 595 and 630 nm. The results showed that the photocatalytic activity of CQDs/K2Ti6O13 hybrid material was greatly enhanced compared with the neat K2Ti6O13 calcined at 300 °C. The narrowed band gap energy (Eg) and transfer of photo-excited electron by CQDs inhibited the immediate combination of electron-hole pairs, thus promoting photocatalytic activity. Moreover, CQDs/K2Ti6O13 exhibited a broad spectrum of photocatalytic ability and it was interesting that the photocatalytic activity decreased with the increase of the irradiation wavelength. Reactive oxygen species (ROS) quenching tests suggested the hole (h+) and hydroxyl radical (OH) played the primary roles in photocatalytic degradation of AMX. Moreover, CQDs/K2Ti6O13 showed good reusability for AMX photocatalytic degradation after five successive runs. This study proposed an available method for titanate nanomaterials modification, and the developed novel CQDs/K2Ti6O13 hybrid material is promising for potential application on antibiotics removal from water and wastewater.

Photocatalytic Degradation of Amoxicillin Using UV/Synthesized NiO from Pharmaceutical Wastewater

The nano nickel(II) oxide (NiO) was synthesized by sol-gel method and used for degradation of Amoxicillin (AMO) from pharmaceutical wastewater. In this laboratory study, the effects of nanoparticle dose (0.25–2 g/L), reaction time (10–120 min), initial antibiotic concentration (25–200 mg/L) and lamp power (15 W) on AMO removal efficiency were assessed in a batch photocatalytic reactor. Antibiotic concentration in output was measured by the spectrophotometer at the maximum wavelength of 280 nm. The optimum nano NiO dose was obtained to be 0.2 g/L. In this study, the removal efficiency decreased with increasing the concentration of AMO. Under optimal conditions of concentration, the removal efficiency was 96%. It was found that increasing the exposure time to UV increased the rate of AMO degradation in solution. The results also showed that the photo-degradation reaction approximately follows the pseudo-first-order kinetics with constant rates of 0.084, 0.074 and 0.046 min-1 for concentrations of 25, 50 and 100 mg/L, respectively. On the basis of the obtained results, it can be concluded that UV/NiO photocatalytic process can efficiently remove AMO from pharmaceutical wastewater.