Photodegradation Of Ibuprofen Research Articles

Photodegradation of ibuprofen by Pd-TiO2/ZSM-5 catalyst

Photodegradation of ibuprofen by Pd-TiO2/ZSM-5 catalyst

Ultrasonic-assisted synthesis of CaCu3Ti4O12/reduced graphene oxide composites for enhanced photocatalytic degradation of pharmaceutical products: Ibuprofen and Ciprofloxacin.

The objective of this research is to create a highly effective approach for eliminating pollutants from the environment through the process of photocatalytic degradation. The study centers around the production of composites consisting of CaCu3Ti4O12 (CCTO) and reduced graphene oxide (rGO) using an ultrasonic-assisted method, with a focus on their capacity to degrade ibuprofen (IBF) and ciprofloxacin (CIP) via photodegradation. The impact of rGO on the structure, morphology, and optical properties of CCTO was inspected using XRD, FTIR, Raman, FESEM, XPS, BET, and UV-Vis. Morphology characterization showed that rGO particles were dispersed within the CCTO matrix without any specific chemical interaction between CCTO and C in the rGO. The BET analysis revealed that with increasing the amount of rGO in the composite, the specific surface area significantly increased compared to the CCTO standalone. Besides, increasing rGO resulted in a reduction in the optical bandgap energy to around 2.09 eV, makes it highly promising photocatalyst for environmental applications. The photodegradation of IBF and CIP was monitored using visible light irradiation. The results revealed that both components were degraded above 97% after 60 min. The photocatalyst showed an excellent reusability performance with a slight decrease after five runs to 93% photodegradation efficiency.

Novel 3D MIL-53(Fe)/graphene aerogel composites for boosted photocatalytic ibuprofen degradation under visible light: Process and mechanism

A highly efficiency process is urgently needed to remove the active pharmaceuticals contamination of water pollution. Herein, 3D MIL-53(Fe)/graphene aerogel (GMA) composites were designed to photodegrade ibuprofen (IBP) in the presence of persulfate (PS). The GMA composites exhibited high-speed electron-hole pairs transfer efficiency, higher specific surface area, excellent IBP degradation ability and easily recycling. The optimizing GMA-1 composite displayed a significant enhanced IBP photodegradation efficiency, in which the IBP degradation efficiency over GMA-1 reached closed to 100% within 60 min under visible light irradiation in the presence of PS. The effect of some vital anions were investigated. Furthermore, SO4·−, ·OH and ·O2− were identified as the main reactive species during the degradation of IBP. The photolytic degradation pathways of IBP and ecotoxicities of the intermediate products were also analyzed. This study may provide an alternative way for effectively removing IBP by 3D metal organic frameworks/graphene aerogel materials.

Photodegradation of ibuprofen using 5-10-15-20-tetrakis(4-bromophenyl) porphyrin conjugated to graphene quantum dots

Ibuprofen (IBU) is a common anti-inflammatory drug that is consumed by many individuals in the world. As such, analytical studies have detected high concentrations of the drug in many waterbodies, which poses a risk of harmful effects on the environment and public health. The hydroxyl radical technologies, a collective of techniques also known as advanced oxidation processes (AOPs), can be utilized to degrade this emerging pollutant. In this study, the photodegradation of ibuprofen using 5,10,15,20-tetrakis(4-bromophenyl) porphyrin conjugated to graphene quantum dots was investigated using a custom-built photoreactor. Three different concentrations of IBU (200, 300 and 500 μM) were utilized as initial concentrations. The pH of the IBU was varied between acidic (pH 3.0), natural (pH 5.0) and alkaline (pH 9.0) to note the effect on IBU degradation as a function of time. The Highest ФΔ was obtained for InTBrP- GDQs (ФΔ = 0.80), followed by InTBrP (ФΔ = 0.74). The photodegradation efficiency of the TBrP-GQDs and InTBrP-GQDs were determined to be 43.2 and 76.1% respectively.

Titanium(IV) oxide nanoparticles functionalized with various meso-porphyrins for efficient photocatalytic degradation of ibuprofen in UV and visible light

Hybrid materials based on nanometric size bare anatase titanium(IV) oxide and meso-functionalized porphyrins were obtained and subsequently characterized in terms of surface morphology with SEM, HR-TEM, nanoparticle size with NTA, crystallinity with XRD and chemical composition with UV-DRS, ATR-FTIR, TGA and Raman spectroscopy. Prepared nanoparticles were studied in photocatalytic degradation of ibuprofen which is an example of an emerging contaminant from the area of pharmaceuticals. During photocatalytic tests, the materials were irradiated with four different wavelengths from UV and visible light ranges. Photocatalytic activity of hybrid materials was compared with bare titanium(IV) oxide and, in the case of said materials, the activity was dependent on the peripheral substituents of porphyrins with different anchoring groups and the wavelengths used for irradiation. For the UV light range tests, hybrid materials showed similar or higher photoactivity in photodegradation of ibuprofen (average 83% and 87% reduction of initial ibuprofen concentration) when compared to bare titanium(IV) oxide (86% reduction). The hybrid materials showed adequate photoactivity (29% and 43% reduction) in the ibuprofen photodegradation study under visible light, unlike bare titanium(IV) oxide (zero activity). Acute toxicities of hybrid materials were studied using Microtox.

Facile construction of sandwich-like composited Sm2MoO6/ZnO/rGO and its activity in photodecomposition of ibuprofen

In this study, Sandwich-like Sm2MoO6/ZnO/rGO (SMZG) composite is produced by the simple hydrothermal method. Various techniques are used to investigate the physicochemical characteristics and morphologies of these heterostructured photocatalysts. The SMZG nanocomposite was successfully formed and the efficiency was tested with photodegradation of Ibuprofen (IBP). XRD analysis confirmed the formation of the body-centered monoclinic structure of Sm2MoO6 compound anchored on the surface of the hexagonal primitive structure of ZnO. According to the DRS UV–Visible spectrum, the nanocomposite photocatalyst has the lowest bandgap (3.12 eV) when compared to Sm2MoO6 (SM), ZnO, and Sm2MoO6/ZnO (SMZ). Under visible-light irradiation for 90 min, the prepared Sm2MoO6/ZnO/rGO (loaded with 20 wt% of Sm2MoO6 and 10 wt% of rGO) accomplish ca. 96.73% IBP photodegradation. The optimum catalyst photodegradation processes can be analytically defined as a function of different catalysts, catalyst dose, and reaction medium pH. As per the scavenging experiments, O2•- radicals are the active species in photodegradation. All these findings provide fresh insight into how to build photocatalysts with high in photodegradation efficiency, inexpensive in cost, rapid response time, and reusability.

Photodegradation of ibuprofen using CeO2 nanostructured materials: Reaction kinetics, modeling, and thermodynamics

Ibuprofen is one the most used non-steroidal anti-inflammatory drug, which is considered an emerging pollutant that may contaminate surface and underground water. Photodegradation using nanomaterials is one of the most sustainable and cheap technologies that can be used in water purification. In this study, the photodegradation efficiency of in-house prepared ceria (CeO2) nanostructured materials towards ibuprofen was assessed under UV irradiation. CeO2 nanoparticles (NPs) were prepared through wet-chemical synthesis and characterized by several techniques. The photodegradation activity of the synthesized CeO2-NPs was compared to the commercial Aeroxide TiO2-P25. Small crystalline CeO2-NPs were obtained with about 15 nm particle size, band-gap of 3.1 eV with irregular morphology. The surface area of CeO2-NPs was estimated to be 76 ± 5 m2/g. Dynamic light scattering analysis revealed that these nanoparticles have a strong tendency to self-aggregate and to form clusters in aqueous suspension. The results showed a slightly better performance of Aeroxide TiO2-P25 compared to CeO2-NPs. On the other hand, five reusability tests confirmed the stability of CeO2-NPs in the reaction conditions, without any significant effect on their photodegradation activity. The goodness of the kinetic modeling of the experimental data was proven through the estimated kinetic parameters, together with the statistical information. The temperature effect confirmed that the higher the temperature, the greater the dissociation rate. Thus, there is a direct relationship between temperature, reaction rate, and the activation energy for each reaction. Furthermore, the thermodynamic parameters, namely: changes in Gibbs free energy (∆G°), enthalpy (∆H°), and entropy (∆S°) have been reported revealing the efficient photodegradation performance of CeO2-NPs.

A robust photocatalyst using silver quantum clusters grafted in titanium dioxide nanotubes

Enhanced photocatalytic activity resulting from the direct electron transfer from noble metal nanoparticles coupled with semiconductor nanostructures is well reported. However, studies on the photocatalytic activity of semiconductor nanostructures coupled with noble metal clusters that exhibit fascinating chemical, optical, and electronic properties are still limited. In this context, we herein report the fabrication of silver quantum clusters grafted on titanium dioxide nanotubes (AgQCs-TNT) towards the photodegradation of ibuprofen and photoreduction of hexavalent chromium ions under visible light irradiation. The structural, chemical, morphological, and optical properties of the as-synthesized samples were studied through X-ray diffraction, energy-dispersive X-ray spectroscopy, transmission electron microscopy, and UV-visible diffuse reflectance spectroscopy. Interestingly, AgQCs-TNT exhibited excellent photocatalytic efficiency in the degradation of ibuprofen and the reduction of hexavalent chromium ions under visible light irradiation in comparison to their pristine counterparts. Role of scavengers and plausible mechanisms pertaining to the improved photocatalytic activity of AgQCs-TNT due to the synergy between the pristine counterparts are discussed.

Rapid sonochemical synthesis of copper doped ZnO grafted on graphene as a multi-component hierarchically structured visible-light-driven photocatalyst

Three-dimensional (3D) hierarchical structures (HSs) have demonstrated excellent properties for various applications that are attributable to their distinctive micro-sized architecture with nanoscale substructures. Recently, the ultrarapid sonochemical approach was found to be an effective strategy for synthesizing single component HSs with uniform morphologies in comparison to the direct precipitation technique. We here report the fabrication of copper doped zinc oxide grafted on graphene layers (ZnO-Cux-GOy) for exploring the capability of this ultrarapid approach for synthesizing multi-component HSs. Interestingly, the morphology of ZnO-Cux-GOy HSs studied through electron microscopy revealed the growth of ZnO HSs decorated with Cu nanoparticles and interconnected by graphene layers. ZnO-Cux-GOy HSs demonstrated three-fold higher efficiency in the photodegradation of ibuprofen (IBU) under visible light irradiation in comparison to pristine ZnO HSs, which is attributable to the combined influence of the doped Cu2+ ions and graphene, enabling improved visible light absorption and inhibiting the recombination of photogenerated charges. Thus, the novel ultrarapid sonochemical synthesis strategy demonstrated here is anticipated to open up a new horizon for the time-saving and scalable design of multi-component HSs of various materials for a myriad of applications.

Solar photocatalytic degradation of ibuprofen with a magnetic catalyst: Effects of parameters, efficiency in effluent, mechanism and toxicity evolution

The environmental-friendly photocatalytic process with a magnetic catalyst CoFe2O4/TiO2 mediated by solar light for ibuprofen (IBP) degradation in pure water, wastewater effluent and artificial seawater was investigated systematically. The study aims to reveal the efficiency, the mechanism and toxicity evolution during IBP degradation. Hydroxyl radicals and photo-hole (h+) were found to contribute to the IBP decay. The presence of SO42- showed no significant effect, while NO3- accelerated the photodegradation, and other anions including HCO3-, Cl-, F-, and Br- showed significant inhibition. The removal efficiency was significantly elevated with the addition of peroxymonosulfate (PMS) or persulfate (PS) ([Oxidant]0:[IBP]0=0.4-4), with reaction rate of 5.3-13.1 and 1.3-2.9 times as high as the control group, respectively. However, the reaction was slowed down with the introduction of H2O2. A mathematic model was employed to describe the effect of ferrate, high concentration or stepwise addition of ferrate was suggested to play a positive role in IBP photodegradation. Thirteen transformation products were identified and five of them were newly reported. The degradation pathways including hydroxylation, the benzene ring opening and the oxidation of carbon were proposed. IBP can be efficiently removed when spiked in wastewater and seawater despite the decreased degradation rate by 41% and 56%, respectively. Compared to the IBP removal, mineralization was relatively lower. The adverse effect of the parent compound IBP to the green algae Chlorella vulgaris was gradually eliminated with the decomposition of IBP. The transformation product C178a which possibly posed toxicity to rotifers Brachionus calyciflorus can also be efficiently removed, indicating that the photocatalysis process is effective in IBP removal, mineralization and toxicity elimination.

Effıcıent photocatalytıc degradatıon of the pharmaceutical ibuprofen over Fe-FSM-16 photo-catalyst under UV ırradıatıon

ABSTRACT Iron doped mesoporous silica (Fe-FSM-16) synthesized by ultrasonic method was used as photo-catalyst for the photo-degradation of ibuprofen (IBP) under UV light. Fe-FSM-16 was characterized by various physicochemical techniques. The effect of the photo-catalyst dose, the effect of pH and the IBP concentration were examined to enhance the IBP photo-degradation. The removal of the IBP was monitored by UV-visible spectrophotometer and liquid chromatography, and the IBP mineralization was measured by the determination of the total organic carbon (TOC) and the chemical oxygen demand (COD). Fe-FSM-16 has a large surface area (181.8 m2.g–1) and an indirect optical band gap energy (Eg = 1.52 eV). The IBP photo-degradation in aqueous solution was achieved in the presence of Fe-FSM-16 and the enhanced reactivity was caused by the presence of iron nanoparticles present inside the FSM structure and dispersed on the FSM.

Efficient Photocatalytic Degradation of Ibuprofen under Visible Light Irradiation Using Silver and Cerium Co‐Doped Mesoporous TiO2

AbstractWater contamination by pharmaceutical compounds has become one of the most serious problem for environment. The use of solar illumination as a renewable energy associated to nanomaterials is an alternative solution for disinfection of wastewater. Therefore, there is a great challenge in green chemistry research to synthesize robust and efficient catalysts for the degradation of organic pollutant under visible light. In this study, we describe new ways to decorated mesoporous TiO2 with cerium (Ce) and silver (Ag) nanoparticles. Indeed, mesoporous TiO2 was co‐doped with Ag and Ce using two different methods: co‐impregnation (Co‐IMP) and co‐deposition precipitation with urea (Co‐DPU). The prepared catalysts were characterized using different analytical techniques such as X‐ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X‐ray spectroscopy (EDX), diffuse reflectance spectroscopy (DR/UV‐vis) and N2 adsorption/desorption. The effect of the preparation method has been evaluated in the photodegradation of ibuprofen (IBP) under visible light irradiation. The obtained results underlined the improvement of photocatalytic activity of mesoporous TiO2 by metals under visible light. A mineralization of IBP up to 98 % was achieved after 4 h irradiation for the catalyst prepared by co‐deposition precipitation with urea. Therefore, this catalyst could be suitable for the treatment of pharmaceuticals in aqueous media using solar light as the energy source.

Constructing a compact heterojunction structure of Ag2CO3/Ag2O in-situ intermediate phase transformation decorated on ZnO with superior photocatalytic degradation of ibuprofen

In this study, the ZnO/Ag2CO3/Ag2O photocatalyst had been successfully fabricated via the facile two-step synthesis method, which included the heterojunction of Ag2CO3 on ZnO, followed by the in-situ phase transformation method of Ag2CO3/Ag2O. The phase transformation from Ag2CO3 to Ag2O over ZnO surfaces was observed in different phase structures and the O atom possessed by Ag2O had diffused towards the Ag2CO3 surface, signifying the presence of Ag2CO3/Ag2O heterostructure over the ZnO. The result indicates that the heterojunction of Ag2CO3/Ag2O over ZnO surfaces exhibited a 99.3% photodegradation of Ibuprofen (IBF) solution under visible-light irradiation, with 10-folds higher reaction rate compared to the pristine ZnO. Compact interfacial heterojunction in ZnO–Ag2CO3-Ag2O sample had promoted effective interfacial charge transfers due to synergistic effect of Ag2CO3/Ag2O heterostructure. This situation leads an extended light absorption due to light sensitive Ag2CO3 and Ag2O which can all lead to an improved photocatalytic activity of the ZnO/Ag2CO3/Ag2O. Experimental and characterization results have shown that a plausible mechanism of highlighting the surface of redox reaction and charge transfer pattern on ZnO/Ag2CO3/Ag2O had been attained. Hence, heterojunction with interface structure could be a promising photocatalyst for photocatalytic applications.

Photodecomposition of ibuprofen over g-C3N4/Bi2WO6/rGO heterostructured composites under visible/solar light

A microwave-assisted hydrothermal preparation of heterostructured graphitic carbon nitride/bismuth tungsten oxide/reduced graphene oxide nanocomposites (denoted as GBR-T, T = microwave irradiation time) is performed. The prepared GBR-T photocatalysts are identified by employing X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HRTEM), time-resolved photoluminescence (TRPL) and nitrogen adsorption-desorption isotherms. The photocatalytic performance of these GBR-T is evaluated by the photocatalytic degradation of ibuprofen (IBP) under the visible light (λ > 420 nm) and solar light irradiation. Among all prepared photocatalysts, ca. 93% of IBP photodegradation can be achieved with a degradation rate constant (k) of 0.011 min−1 under visible-light irradiation upon the optimal microwave-assisted reaction time of 60 min. The improvement is primarily attributable to the higher crystallization degree, specific surface area and increased charge transfer efficiency as verified by XRD, nitrogen adsorption-desorption isotherms and TRPL, respectively. The photocatalytic performance of this catalyst is further enhanced in the photodecomposition of IBP (ca. 98.6%) under sun light irradiation. The electron spin resonance (ESR) and liquid chromatography-mass/mass spectrometry (LC–MS/MS) studies show that the superoxide radicals and hydroxyl radicals are the dominant active species in the photocomposition of IBP and degradation intermediates are formed through three probable photodegradation pathways. This investigation provides a simple way to prepare triple 2D heterojuction photocatalysts which could be effectively used in the advanced oxidation process for removal of emerging contaminants in wastewater by using renewable energy.

Sm3+ induced-SrWO4 phosphor: analysis of photoluminescence and photocatalytic properties with electron density distribution studies

In the present study, we designed a spherical shape like Sr1−xSmxWO4 (x = 0.0, 0.01, 0.02, 0.03, 0.04 and 0.05) materials by simple co-precipitation route and evaluated its photoluminescence and photocatalytic properties. The structural and morphological properties of as-prepared materials were studied by powder X-ray diffraction method, X-ray photoelectron spectroscopy, scanning electron micrographic images and transmission electron micrographic images. The photoluminescence behavior of Sm3+-doped SrWO4 for visible excitation (405 nm) was examined to analyze its use as white LED. The emission spectra consist of intra 4f transition of Sm3+ such as 4$${\text{G}}_{5/2}\to$$6$${\text{H}}_{5/2}$$ (561 nm), 4$${\text{G}}_{5/2}\to$$6$${\text{H}}_{7/2}$$ (601 nm), 4$${\text{G}}_{5/2}\to$$6$${\text{H}}_{9/2}$$ (642 nm) and 4$${\text{G}}_{5/2}\to$$6$${\text{H}}_{11/2}$$ (711 nm), respectively. Furthermore, the emission wavelength at 601 and 642 nm suggests a strong orange and red emission, which can be applied for the application for near-UV excitation. On the other hand, Sm3+-doped SrWO4 played excellent catalyst towards the photodegradation of Ibuprofen (IBF). The obtained results from the UV-Vis spectroscopy suggested that 3% of Sm3+-doped SrWO4 had high photocatalytic activity compared to other materials. The degradation efficiency of Sr0.97Sm0.03WO4 toward IBF was observed about 97% within 80 min under visible irradiation and it showed good stability by observing the reusability of catalyst. These results suggested that the Sm3+-doped SrWO4 material are suitable candidate for application in photoluminescence and photocatalysis.

Photodegradation of ibuprofen and four other pharmaceutical pollutants on natural pigments sensitized TiO2 nanoparticles.

Pharmaceuticals and personal care products (PPCPs) in water system have drawn increasing concerns in recent years. TiO2 -based photodegradation has shown great potential as a low-cost and sustainable technology in water treatment, however, can only use the UV light range of solar radiation which makes the system less efficient. Dyes have been studied to improve the TiO2 system light-harvesting range, but studies on environmental friendly natural dyes are rare. In this study, a screening method using UV-Vis spectra analysis was carried out on a group of 22 different tropical natural plants for the potential applications on dye-sensitized TiO2 in PPCP treatment. As a result, Begonia "Martin's Mystery" significantly increased TiO2 photodegradation efficiency toward ibuprofen treatments which is first time reported in literature as our best knowledge. Moreover, the promising discovery of Begonia application in ibuprofen treatment has been successfully applied to warfarin and famotidine treatment. Similar results were expanded to many other Begonia species which indicate that Begonia extracts could be excellent sensitizers for TiO2 -based photodegradation of PPCPs. Our discovery suggested that the screening process may potentially open a brand-new way for future TiO2 photodegradation studies before the complex and time-consuming detailed mechanism studies. PRACTITIONER POINTS.: Natural dyes were screened as sensitizers for TiO2 photodegradation of ibuprofen. Ibuprofen photodegradation efficiency was increased twice using Begonia "Martin's Mystery." The Begonia applications were extended to warfarin, trimethoprim, and famotidine. Promising results were also observed using five other Begonia species.

Ibuprofen Photodegradation by Ag2O and Ag/Ag2O Composites Under Simulated Visible Light Irradiation

Ag2O was synthesized by the precipitation method and it was used as support to prepare Ag/Ag2O nanocomposites using different sodium citrate volumes to control the size and amount of Ag nanoparticles. Materials were characterized by X-ray powder diffraction, diffuse reflectance spectroscopy, X-ray photoelectron spectroscopy, scanning and transmission electron microscopy and nitrogen adsorption–desorption at − 196 °C analyses, respectively. Ibuprofen was selected as a probe molecule and materials were assessed as photocatalysts under simulated visible light irradiation. The SEM and TEM analysis revealed the presence of Ag nanoparticles over Ag2O support showing a size increase as citrate volume increased. By means of DRS analysis a band gap shift was observed, suggesting the formation of metallic silver during Ag impregnation while XPS results proved the co-existence of Ag0 and Ag2O composites. On the other hand, the photocatalysis results revealed the formation of intermediaries during ibuprofen photodegradation. Visible light absorption by Ag nanoparticles produced superoxide anion radicals (due to surface plasmon resonance) that enhanced the formation of intermediaries. The reaction mechanism proposed involves the generation of a Ag/Ag2O heterojunction where the metal acts as an electron scavenger decreasing the recombination of the e−–h+ pair.

Microwave-assisted synthesis of triple 2D g-C3N4/Bi2WO6/rGO composites for ibuprofen photodegradation: Kinetics, mechanism and toxicity evaluation of degradation products

In this study, the visible-light-driven Z-scheme g-C3N4/Bi2WO6/rGO heterojunctions with 2D/2D/2D configurations are prepared via a facile, rapid and low temperature microwave-assisted method. The physicochemical properties and morphologies of these heterostructured photocatalysts are characterized by various spectroscopies such as XRD, XPS, TEM/SEM, PL, FT-IR, UV–Visible spectroscopy and nitrogen adsorption measurements. The prepared g-C3N4/Bi2WO6/3 wt% rGO photocatalysts (incorporated with optimal 3 wt% of rGO) possess ca. 86 and 98% of ibuprofen (IBF) photodegradation under the visible light (λ > 420 nm) and solar light irradiation, respectively. The formation of well crystallized structure, morphology (nanoplates structure of Bi2WO6), higher visible light absorption and specific surface area (25.4 m2 g−1) are responsible for the superior performance of g-C3N4/Bi2WO6/3 wt% rGO. Moreover, the larger interfacial contact (identified by HRTEM) between triple 2D g-C3N4/Bi2WO6/rGO heterostructures can lead to surpassing interfacial charge carrier dynamics and reduce the combination of electron-hole pairs. IBF photodegradation intermediates and the corresponding reaction mechanisms are further investigated by using LC-MS/MS, indicating the superoxide radical (O2−) and hydroxyl radicals (OH) are involved in the photodegradation of IBF and accordingly five intermediates are produced via three possible reaction pathways. The anti-hormonal effects of IBF and the photodegraded intermediate products are also evaluated by yeast-based bioassays. The results show that the intermediate products of photodegraded IBF have lower antagonistic effect on human hormone receptors than the pristine IBF.

Evidence of non-photo-Fenton degradation of ibuprofen upon UVA irradiation in the presence of Fe(III)/malonate

The degradation of ibuprofen (IBP) in the presence of the complex Fe(III)-malonate in aqueous solution under 365 nm radiation has been investigated. Photolysis of Fe-malonate mainly generates the CH2COOH radical, instead of HO radicals. This is contrary to the generally observed behaviour with other iron-carboxylate complexes, where H2O2 is produced and HO radicals are generated. The photodegradation of the IBP/Fe(III)-malonate/UVA system is slower than expected because the photo-Fenton reaction takes place only to a limited extent. Reaction rate profiles show an induction period, and IBP/Fe-malonate system runs inversely to Fe(II) formation. Almost complete IBP disappearance takes place after five hours with [IBP]0 = 0.05 mM, [Fe(III)] = 0.3 mM, [malonate]0 = 1.2 mM, pH = 2.8, λirr = 365 nm, T ca. 293 K. Kinetic profiles resemble first order decays as [H2O2] increases, and both the efficiency of the process and the reaction rate increase with acidity. Addition of Ca(II), Mg(II) and Mn(II) to the system IBP/Fe(III)-malonate/UVA has no effect on the degradation, whereas Cu(II) slightly inhibits it. Transformation photoproducts are more difficult to photodegrade than the mixture itself, only ca. 40% TOC disappears after 360 min and 64% COD is removed after 24 h of irradiation (IBP/Fe(III)-malonate/UVA system). Seven transformation photoproducts were identified by HPLC-MS and the corresponding reaction mechanism has been proposed. Sunlight irradiation improves the reaction, showing the feasibility of IBP photodegradation in natural environments under carefully controlled conditions.

Preparation of magnetic nanosphere/nanorod/nanosheet-like Fe3O4/Bi2S3/BiOBr with enhanced (0 0 1) and (1 1 0) facets to photodegrade diclofenac and ibuprofen under visible LED light irradiation

A novel magnetic nanosphere/nanorod/nanosheet-like photocatalyst Fe3O4/Bi2S3/BiOBr was fabricated via a facile one-pot solvothermal method firstly and exhibited excellent photocatalytic performance for diclofenac (DCF) and ibuprofen (IBU) removal, where the removal efficiencies of DCF and IBU were 93.81% and 96.78% after 40 min and 30 min visible LED light irradiation, respectively. The best preparation ratios with Bi2S3 mass were 4% and 1% for DCF and IBU removal respectively, which might be attributed to better crystallinities of (0 0 1) and (1 1 0) facets respectively. Besides, enhanced charge separation and better crystallinity with introduction of Fe3O4 and Bi2S3 promoted higher photocatalytic performance of Fe3O4/Bi2S3/BiOBr compared with pure BiOBr, Bi2S3 and Bi2S3/BiOBr. Influencing factors experiments (pH, common anions, DOM) results showed beneficial or detrimental effects to a certain extent. While removal efficiencies in matrices of Yellow River (DCF: 55.65%; IBU: 54.90%) and Wastewater treatment plant (DCF: 68.66%; IBU: 58.90%) exhibited lower than those in ultrapure water. Moreover, h+ and e− played the uppermost roles in the DCF and IBU photodegradation according to active species trapping experiment results. Furthermore, four and two main degradation pathways for DCF and IBU removal respectively through 3D EEMs and HRMS analyses were proposed. Lastly, easy separation from water and excellent reusability proved its better potential for emerging pollutants removal in environment remediation area.