Photocatalytic Degradation Of Ibuprofen Research Articles

Visible-light-driven photocatalytic degradation of ibuprofen by Cu-doped tubular C3N4: Mechanisms, degradation pathway and DFT calculation

The copper-modified tubular carbon nitride (CTCN) with higher specific surface area and pore volume was prepared by a simple in-situ hydrolysis and self-assembly. Increased ∼4.7-fold and ∼2.3-fold degradation rate for a representative refractory water pollutant (Ibuprofen, IBP) were achieved with low-energy light source (LED, 420 ± 10 nm), as compared to graphitic carbon nitride (GCN) and tubular carbon nitride (TCN), respectively. The high efficiency of IBP removal was supported by narrow band gap (2.15 eV), high photocurrent intensity (1.10 μA/cm2) and the high surface -OH group (14.75 μg/cm3) of CTCN. According to analysis of the various reactive species in the degradation, the superoxide radical (•O2−) played a dominant role, followed by •OH and h+, responsible for IBP degradation. Furthermore, Fukui functions were employed to predict the active sites of IBP, and combined with the HPLC-MS/MS results, possible mechanisms and pathways for photocatalytic degradation were indicated. This study will lay an important scientific foundation and a possible new approach for the treatment of emerging aromatic organic pollutants in visible-light-driven heterogeneous catalytic oxidation environment.

Environmentally Friendly Fabrication of High-Efficient Fe-ZnO/Citric Acid-Modified Cellulose Composite and the Enhancement of Photocatalytic Activity in the Presence of H2O2

In the present study, a novel Fe-ZnO/citric acid-modified cellulose composite (x%Fe-ZnO-y%CAC) was synthesized using an environmentally friendly hydrothermal method. The obtained samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), UV–vis diffuse reflectance spectroscopy (DRS), Fourier transform infrared spectroscopy (FTIR), nitrogen physisorption, and electrochemical and photocurrent density analyses. The influence of the additives from the series of x%Fe-ZnO-y%CAC photocatalysts with Fe content from 0 to 5% and CAC content from 0 to 80% on photocatalytic degradation of ibuprofen (IBU) under simulated solar light was investigated. The photocatalyst 0.5%Fe-ZnO-40%CAC showed high photocatalytic activity of 0.0632 min−1 first-order kinetic rate constant and 46% TOC reduction of IBU under simulated solar light irradiation. Additionally, H2O2-assisted photocatalytic process was investigated for facilitating the IBU degradation in the presence of 0.5%Fe-ZnO-40%CAC; the first-order kinetic rate constant was 2.7 times higher compared to the process without addition of H2O2. Moreover, the effect of radical scavengers was examined to explain the degradation mechanism of IBU by synthesized photocatalysts supported with H2O2. The demonstrated system provides a low-cost and green approach to improve the photocatalytic activity of x%Fe-ZnO-y%CAC photocatalysts.

Green Synthesis of Hexagonal Hematite (α-Fe2O3) Flakes Using Pluronic F127-Gelatin Template for Adsorption and Photodegradation of Ibuprofen.

Hematite (α-Fe2O3) with uniform hexagonal flake morphology has been successfully synthesized using a combination of gelatin as natural template with F127 via hydrothermal method. The resulting hematite was investigated as adsorbent and photocatalyst for removal of ibuprofen as pharmaceutical waste. Hexagonal flake-like hematite was obtained following calcination at 500 °C with the average size was measured at 1–3 µm. Increasing the calcination temperature to 700 °C transformed the uniform hexagonal structure into cubic shape morphology. Hematite also showed high thermal stability with increasing the calcination temperatures; however, the surface area was reduced from 47 m2/g to 9 m2/g. FTIR analysis further confirmed the formation Fe-O-Fe bonds, and the main constituent elements of Fe and O were observed in EDX analysis for all samples. α-Fe2O3 samples have an average adsorption capacity of 55–25.5 mg/g at 12–22% of removal efficiency when used as adsorbent for ibuprofen. The adsorption capacity was reduced as the calcination temperatures increased due to the reduction of available surface area of the hexagonal flakes after transforming into cubes. Photocatalytic degradation of ibuprofen using hematite flakes achieved 50% removal efficiency; meanwhile, combination of adsorption and photocatalytic degradation further removed 80% of ibuprofen in water/hexane mixtures.

Functioned catalysts with magnetic core applied in ibuprofen degradation.

In the present work, the performance of Ag/ZnO/CoFe2O4 magnetic photocatalysts in the photocatalytic degradation of ibuprofen (IBP) was evaluated. This study considered the use of pure Ag/ZnO (5% Ag) and also the use of the Ag/ZnO/CoFe2O4 magnetic catalysts containing different amounts (5, 10 and 15% wt) of cobalt ferrite (CoFe2O4). The catalysts were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD) and photoacoustic spectroscopy. To carry out the photocatalytic degradation reaction, different concentrations of the ibuprofen contaminant solution (10, 20 and 30 ppm) and different concentrations of photocatalyst were tested (0.3 g L-1, 0.5 g L-1 and 1.0 g L-1). The reaction parameters studied were: IBP concentration, catalyst concentration, adsorption and photolysis, influence of the matrix, radiation source (solar and artificial) and the effect of organic additive. At the end of the photocatalytic tests, the best operating conditions were defined. Considering the obtained results of degradation efficiency and magnetic separation, the optimal parameters selected to proceed with the other tests of the study were: ibuprofen solution concentration 10 ppm, Ag/ZnO/CoFe2O4 (5%) catalyst at a concentration of 0.3 g L-1 and pH 4.5 of the reaction medium. The results indicated the feasibility of magnetic separation of the synthesized catalysts. A long duration test indicated that the catalyst exhibits stability throughout the degradation reaction, as more than 80% of IBP was degraded after 300 minutes. The photocatalytic activity was directly affected by the ferrite load. The higher the nominal load of ferrite, the lower the performance in IBP degradation. It was also observed that the smallest amount of ferrite studied was enough for the catalyst to be recovered and reused. The adsorption and photolysis tests did not show significant results in the IBP degradation. In addition, it was possible to verify that the aqueous matrix, the use of solar radiation and the addition of additive (acid formic) were interfered directly in the process. The catalyst reuse tests indicated that it can be recovered and reused at least three times without considerable catalytic activity loss.

Photocatalytic degradation of ibuprofen on S-doped BiOBr

Doping heterogeneous atoms into BiOX is recognized as an effective method to improve its photocatalytic activity. Here, S-doped BiOBr (S–BiOBr) was synthesized via a solvothermal method in the absence of water, which is supposed to substitute O as S2− in the lattice. This material is firstly used for the visible-light-driven degradation of ibuprofen, a model anti-inflammatory drug. The degradation efficiency of S–BiOBr is much higher than that of pure BiOBr. The degradation kinetic constant for S–BiOBr (2.48 × 10−2 min−1) is about 3 times as high as that of pure BiOBr (0.83 × 10−2 min−1). It is found that S-doping tunes the band structure of BiOBr, leading to a narrower band gap and thus higher utilization efficiency of visible light. The degradation of ibuprofen on S–BiOBr can be attributed to the generation of H2O2 and OH radicals. OH radical plays a synergistic role along with holes in the photocatalytic degradation process, which is supposed to be better than the reported single hole- or superoxide-dominant reaction. This work reveals a previously unrecognized and more efficient method for the degradation of organic contaminants on BiOBr.

Photocatalytic degradation of ibuprofen using titanium oxide: insights into the mechanism and preferential attack of radicals.

The present work studied ibuprofen degradation using titanium dioxide as a photocatalyst. Mechanistic aspects were presented and the preferred attack sites by the OH˙ radical on the ibuprofen molecule were detailed, based on experimental and simple theoretical-computational results. Although some previous studies show mechanistic proposals, some aspects still need to be investigated, such as the participation of 4-isobutylacetophenone in the ibuprofen degradation and the preferred regions of attack by OH˙ radicals. The photodegradation was satisfactory using 0.03 g of TiO2 and pH = 5.0, reaching 100% decontamination in 5 min. The zeta potential curve showed the regions of attraction and repulsion between TiO2 and ibuprofen, depending on the pH range and charge of the species, influencing the amount of by-products formed. Different by-products have been identified by GC-MS, such as 4-isobutylacetophenone. Ibuprofen conversion to 4-isobutylacetophenone takes place through decarboxylation reaction followed by oxidation. The proposed mechanism indicates that the degradation of ibuprofen undergoes a series of elementary reactions in solution and on the surface. Three different radicals (OH˙, O2−˙ and OOH˙) are produced in the reaction sequence and contribute strongly to the oxidation and mineralization of ibuprofen and by-products, but the hydroxyl radical has a greater oxidation capacity. The simple study using the DFT approach demonstrated that the OH˙ radical attacks preferentially in the region of the ibuprofen molecule with high electronic density, which is located close to the aromatic ring (C Created by potrace 1.16, written by Peter Selinger 2001-2019 ]]> C bond). The presence of the OH˙ radical was confirmed through a model reaction using salicylic acid as a probe molecule.

Facile synthesis of mesoporous black N–TiO2 photocatalyst for efficient charge separation and the visible-driven photocatalytic mechanism of ibuprofen degradation

The present study aimed to investigate the photodegradation of ibuprofen (IPF) by using black N–TiO2 under visible LED illumination. The as-synthesized black N–TiO2 nanoparticles were characterized by field emission scanning electron microscope (FESEM) equipped with energy dispersive X-ray spectrometer (EDS) detector, transmission electron microscopy (TEM), high resolution transmission electron microscopy (HRTEM), X-ray diffraction (XRD), UV visible diffuse reflectance spectroscopy (UV-DRS), and Brunauer–Emmett–Teller (BET) techniques. The potential photocatalytic activity of the synthesized nanoparticles was assessed by degradation and mineralization of IPF under visible LED light irradiation. Compared to N–TiO2, the black N–TiO2 exhibited higher degradation (96%) and mineralization (81%) efficiency for IPF under selected operational conditions. We observed that codoping of N and Ti3+ narrowed the band gap (2.1 eV) and decreased the recombination of photogenerated carriers. Pseudo-first order kinetic model was best fitted with the experimental results (R2 > 0.99 for different IPF concentrations). Radical-scavenging tests showed that hydroxyl radicals (•OH), holes (h+), and superoxide radicals (•O2−) are involved in the photocatalytic degradation of IPF, however •OH and •O2− played more important roles. The energy consumption of the system for different initial IPF concentrations was around 16.6–38.7 kWh/m3, indicating that the LED-black N–TiO2 process is energy-efficient. The results revealed that the photocatalytic activity of the black N–TiO2 is not changed much, even after 5 cycles, demonstrating its excellent photocatalytic stability and reusability. According to the findings, LED-black N–TiO2 process has the potential to be applied for facile removal of contaminants of emerging concern (CECs) such as IPF from water resources.

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.

Photocatalytic degradation of ibuprofen and naproxen in water over NS-TiO2 coating on polycarbonate: Process modeling and intermediates identification

Nitrogen and sulfur doped TiO2 was coated on polycarbonate (NS-TiO2@PC) by simple deposition method. The coated film was characterized by field emission scanning electron microscope and atomic force microscope. The photocatalytic activity of the NS-TiO2@PC was evaluated through degradation of ibuprofen and naproxen under visible light irradiation. Optimization results showed that the maximal degradation efficiencies of 83% and 100% were achieved for ibuprofen and naproxen, respectively. In addition, the possible photodegradation intermediates were identified by liquid chromatography–mass spectrometry. This study proved that the NS-TiO2@PC had excellent stability during photodegradation of pollutants and will have practical applications for environmental remediation.

Photocatalytic degradation of ibuprofen using modified titanium oxide supported on CMK-3: effect of Ti content on the TiO2 and carbon interaction

TiO2 nanoparticles dispersed in ordered mesoporous CMK-3 carbon with different Ti contents were successfully synthesized and their activity in the photocatalytic degradation of ibuprofen was presented.

Design of a Z-scheme g-C3N4/CQDs/CdIn2S4 composite for efficient visible-light-driven photocatalytic degradation of ibuprofen

A novel Z-scheme photocatalyst consisting of acidified graphitic carbon nitrogen (ag-C3N4)/carbon quantum dots/CdIn2S4 (CN/CQDs/CIS) was successfully synthesized via a one-step hydrothermal method. The optimized CN-2/CQDs-3/CIS exhibited significantly improved photocatalytic performance in the degradation of ibuprofen under visible-light irradiation. Based on a series of characterizations, the ag-C3N4 and CQDs were distributed uniformly on the surface of the cubic spinel structure of CIS, with intimate contact among the materials. This intimate heterogeneous interface facilitated the migration of photogenerated carriers, further leading to enhanced photocatalytic performance. These results also indicated that the CQDs not only connect ag-C3N4 with CIS through covalent bonds but also enhance the visible-light adsorption. According to the analysis of the UV–vis diffuse reflectance spectra (DRS) and Mott-Schottky curves, the mechanism of the Z-scheme heterojunction is proposed. The CQDs serve as electron mediators and transfer the electrons in the conduction band (CB) of ag-C3N4 to recombine with the holes in the valence band (VB) of CIS in the Z-scheme, leading to the enhanced separation efficiency of the photogenerated electrons in the CB of ag-C3N4 and the holes in the VB of CIS. The pollutant IBU was degraded by h+, ·O2− and ·OH, as determined by electron paramagnetic resonance (EPR) analysis.

Enhanced photocatalytic degradation of ibuprofen in aqueous solution under visible-light irradiation: Effects of LaFeO3 and Cu/LaFeO3

The efficiency of LaFeO3 and Cu-doped LaFeO3 nanopowders in the photocatalytic degradation of ibuprofen (IBP) has been investigated. Aqueous solutions of IBP in the presence of photocatalyst, of H2O2, and both photocatalyst and H2O2, were irradiated under visible-light. The experiments were carried out on aqueous suspensions containing 5.0 x10-5 M of IBP, 0.003 M of H2O2, 0.130 g L-1 of catalyst. The concentration of H2O2 corresponded to a mole amount that largely exceeded the amount for the complete oxidation of IBP. Moreover, concentration of H2O2 was about 1/30 than that used in typical studies on the heterogeneous Fenton-like process. The composition of the reaction solution during photocatalytic experiment was followed by UV-Vis spectroscopy and HPLC. The results showed the higher photocatalytic activity of Cu-doped LaFeO3 (5 and 10 mol%) compared to pure LaFeO3 [1]. With both photocatalysts the main degradation product of IBP was 4-isobutylacetophenone (4-IBAP), which showed a slower photocatalytic degradation than the parent compound.

Photocatalytic degradation of ibuprofen in water using TiO2 and ZnO under artificial UV and solar irradiation.

The degradation of anti-inflammatory and antipyretic drug (Ibuprofen; IBP) has been described in this study by using photocatalytic-based advanced oxidation processes. The catalysts (TiO2 and ZnO) were activated by irradiation of artificial UV lamp and solar rays for the generation of highly oxidizing species which resulted in the degradation of IBP to intermediates and finally to carbon dioxide and water. In solar reactor, quartz and borosilicate tubes were installed for absorption of required ultraviolet rays and curved chrome plates were used to reflect and concentrate rays on the tubes containing feed mixture. The liquid chromatography, Total organic carbon (TOC), and Chemical oxygen demand (COD) tests were employed to determine the degradation rates and demineralization of solution samples. At catalyst dosing of 1-1.5g/L, TiO2 -based experiments showed high degradation rate under acidic conditions. Similarly, for ZnO catalyst, 1g/L dozing rate was found to be effective under neutral conditions (pH=7.0). UV lamp-based photocatalysis had higher degradation rate as compared to that of solar reactor. Moreover, better absorption of solar rays by quartz tubes resulted in higher degradation than that in borosilicate tubes. For UV lamp photocatalysis, the TOC and COD reduction was higher. With improved catalyst doping and better solar reactor design, solar-based IBP degradation could be more promising than UV-based catalysis. PRACTITIONER POINTS: TiO2 and ZnO were employed to generate oxidizing agents for comparative photocatalytic degradation. Degradation rate of Ibuprofen with TiO2 was much higher compared to ZnO. Quartz material was found more effective as radiation absorbing material than borosilicate glass for solar photo catalysis. Influence of catalyst loading (TiO2 and ZnO) and pH conditions on degradation rate and mineralization of IBP was examined. IBP is a carcinogenic and endocrine disrupting drug so its degradation in water can protect ecological and human life.

Magnetically separable BiOBr/Fe3O4@SiO2 for visible-light-driven photocatalytic degradation of ibuprofen: Mechanistic investigation and prototype development.

The increasingly ubiquitous release of emerging refractory pollutants into water is a serious concern due to associated risks. In this study, mesoporous hierarchical BiOBr/Fe3O4@SiO2-a solvothermally synthesized visible-light-driven magnetic photocatalyst-not only exhibited fast kinetics (t1/2 = 8.7 min) in the photocatalytic degradation of ibuprofen in water but also achieved almost complete mineralization over a prolonged irradiation of 6 h. Various reactive species, including O2¯, OH, and H2O2, were detected, while the scavenging experiments revealed that eCB--mediated reactions and direct-hole oxidation are the major degradation routes. The magnetically recycled BiOBr/Fe3O4@SiO2 maintained ∼80% of its initial photocatalytic activity even after five consecutive cycles. The typically copresent wastewater constituents, including NOM and anions, inhibited the photocatalytic performance to varying extents, and hence necessitated an increase in the photocatalyst dosage to achieve complete ibuprofen degradation in real sewage. Based on the findings of batch experiments, the process was scaled up by developing a 5 L prototype photocatalytic reactor integrated with an electromagnetic separation unit. The results of prototype photocatalytic experiments were comparable to those of batch experiments, and an electromagnetic separation efficiency of ∼99% was achievable in 5 min.

Photocatalytic degradation of ibuprofen in water using TiO2/UV and g-C3N4/visible light: Study of intermediate degradation products by liquid chromatography coupled to high-resolution mass spectrometry

The photocatalytic degradation of ibuprofen with TiO2 nanoparticles (NPs) and UV light and with graphitic carbon nitride (g-C3N4) 2D nanosheets and visible light are proposed and compared as advanced oxidation treatments for the removal of ibuprofen in water. By-products formed with both photocatalytic systems have been tentatively identified based on the results of ultra-high-performance liquid chromatography coupled to high-resolution mass spectrometry, using a quadrupole-time of flight mass spectrometer in positive and negative ionization modes, which allowed to obtain the elementary composition of their precursors and fragment ions. The removal of ibuprofen and the by-product formation were studied at three pH values. Ibuprofen depletion followed pseudo fist-order kinetics with rate constants of 0.04, 1.0 and 0.0006 min−1 at pH 2.50, 5.05 and 12.04 for TiO2/UV and 0.03, 0.007 and 0.0005 min−1 at pH 2.51, 5.05 and 11.33 for g-C3N4/vis, respectively. Around eighteen by-products have been detected with slight differences between the two photocatalytic systems studied. The evolution of the main common by-products (tentatively identified as 1-(4-ethylphenyl)-2-methylpropan-1-one, 1-(4-isobutylphenyl)ethan-1-ol, 1-(4-ethylphenyl)-2-methylpropan-1-ol and 1(-4-acetylphenyl)-2-methylpropan-1-one) were monitored and the results were consistent with reaction pathways based on hydroxyl radical attacks following/followed by decarboxylation. Moreover, some by-products have been reported for the first time in the photocatalytic oxidation of ibuprofen.

Multiphase TiO2 surface coating g-C3N4 formed a sea urchin like structure with interface effects and improved visible-light photocatalytic performance for the degradation of ibuprofen

In this research, we did not use any template, but a prickly structure urchin like morphology made of composite TiO2/g-C3N4 was synthesized by a one-step solvothermal method. It is generally reported that TiO2 is a pure phase, besides, the photocatalytic effect of multiphase TiO2 will be better. After the g-C3N4 was successfully loaded on the TiO2 surface, the morphology did not change. The special sea urchin morphology provides more active sites for catalysis. The band gap becomes smaller, because two materials were combined to form an interface effect. Meanwhile, it could effectively separate electron hole pairs, and promote charge transfer efficiency. More active substances were produced under visible light, such as superoxide radicals and holes. The scavenging experiment further confirms that superoxide radicals and holes play an important role in the catalytic process. The photocatalytic degradation of ibuprofen under visible light was improved. A possible enhanced photocatalytic mechanism of g-C3N4/TiO2 heterojunction photocatalysts was proposed.

Photocatalytic degradation of ibuprofen over BiOCl nanosheets with identification of intermediates

Photocatalysis directed at the removal of persistent organic pollutants, including pharmaceuticals, has been the subject of intense recent research. Bismuth oxychloride (BiOCl) has emerged as a potential alternative to traditional photocatalysts and has shown competitive removal efficiencies. However, pathways responsible for BiOCl photodegradation have not been well characterized. The present work is the first to determine, using LC-MS/MS analysis, the pathways by which BiOCl removes ibuprofen (IBP) from water. HPLC-DAD and LC-MS/MS analyses show that BiOCl converts IBP to two primary photochemical products, 4-isobutylacetophenone (IBAP) and 1-(4-isobutylphenyl)ethanol (IBPE). The reactivity for BiOCl is attributed to interactions of the carboxylic acid group of IBP with holes in the valence band. Hydroxylated-IBP was not detected in BiOCl photocatalytic degradation experiments which would be expected in a process driven by the formation and reactivity of reactive oxygen species. These data were used to formulate a photocatalytic degradation pathway for IBP and highlight the importance of studying both primary and secondary degradation reactions for photocatalytic studies.

Integration of plasmonic effect into spindle-shaped MIL-88A(Fe): Steering charge flow for enhanced visible-light photocatalytic degradation of ibuprofen

High electron-hole separation efficiency and wide spectrum absorption are desired for improving the photocatalytic activity. In this research, we integrate plasmonic Ag/AgCl with a typical semiconductor-like metal-organic framework MIL-88A(Fe) to form Ag/AgCl@MIL-88A(Fe) (ACMA) nanocomposites by a facile one-pot solvothermal method. The results demonstrate that ACMA nanocomposites not only broaden the visible-light absorption of MOFs, but also greatly accelerate photo-induced charge transfer rate. EDS mapping and HRTEM results suggest that Ag/AgCl is uniformly and densely dispersed on the surface of MOF, which is beneficial for charge flow and expedites the charge migration. By virtue of the structural and compositional features, these unique ACMA nanocomposites perform excellent photocatalytic activity on ibuprofen (IBP) in terms of high degradation efficiency, high mineralization and excellent cycling stability. ACMA-2 (Fe:Ag = 2:1) displays highly efficient photocatalytic activity on IBP under visible light irradiation, and the corresponding photo-degradation rate is 10.8 and 40.4 folds higher than that of MIL-88A(Fe) and Ag/AgCl, respectively. Total organic carbon (TOC) removal of IBP photodegradation reaches 91% by the catalysis of ACMA-2. Combined with the electrochemical tests, quencher experiments and analysis of related degradation products identified by ion chromatography (IC) and LC-MS-MS, oxidation by superoxide radicals (O2−) as well as holes (h+) and electrons (e−) is the dominant degradation process in the photocatalytic degradation of IBP. This work provides a new perspective for the preparation of environment-stable and efficient MOF-based photocatalysts by steering charge flow.

One-pot hydrothermal synthesis of g-C3N4/Ag/AgCl/BiVO4 micro-flower composite for the visible light degradation of ibuprofen

A novel visible-light-driven g-C3N4/Ag/AgCl/BiVO4 micro-flower composite was synthesized by a simple one-pot hydrothermal method. Morphological and structural studies of the composite showed the formation of microsheets of different sizes (280–450 nm) and (1 2 1)/(0 4 0) as the preferential planes. Optical absorption examination of g-C3N4/Ag/AgCl/BiVO4 revealed its small band gap (Eg = 2.4 eV), which enables it to absorb light in the visible light region. The photocatalytic activity of the g-C3N4/Ag/AgCl/BiVO4 was determined by the photocatalytic degradation of ibuprofen (IBU) under visible light irradiation. Compared to BiVO4, Ag/AgCl/BiVO4 and g-C3N4/BiVO4, the g-C3N4/Ag/AgCl/BiVO4 showed remarkable efficiency by degrading 94.7% of IBU in 1 h at a photocatalyst dosage of 0.25 g/L. Furthermore, the photocatalytic degradation performance of g-C3N4/Ag/AgCl/BiVO4 increased when the intensity of the (1 2 1)/(0 4 0) planes increased. Under dark conditions, insignificant adsorption of IBU was observed on the surface of g-C3N4/Ag/AgCl/BiVO4 due to its low surface area (3.67 m2g−1). The excellent photocatalytic activity is likely due to visible light absorption and increased lifetime of photogenerated electron-hole pairs along the heterojunction. The kinetics of the IBU photodegradation was found to follow the pseudo-first-order reaction. The influence of the key parameters during synthesis (i.e., pH, amount of g-C3N4, amount of AgNO3, photodeposition time, and autoclaving time) on the photocatalytic activity of g-C3N4/Ag/AgCl/BiVO4 was also investigated. It was found that the Ag content and pH are the most crucial parameters in the enhancement of photocatalytic activity. The g-C3N4/Ag/AgCl/BiVO4 produced 4.8 µmol of CO2 showing its mineralization and the remaining intermediates were confirmed by LCMS.

Synthesis of Fe3O4/Bi2WO6 nanohybrid for the photocatalytic degradation of pharmaceutical ibuprofen under solar light

Abstract Magnetic Fe3O4/Bi2WO6 nanohybrids were prepared via a two-step approach. Fe3O4 nanospheres were synthesized using a solvothermal method in polyol media and Bi2WO6 nanocrystals were formed by the subsequent hydrothermal process. In the preparation process of Bi2WO6 nanoparticles, tungstophosphoric acid hydrate (H3PW12O40) was used as an acidic agent. The activity of the photocatalyst was evaluated by the photocatalytic degradation of ibuprofen (IBP) from an aqueous solution with solar light. The as-prepared nanohybrid, which could be easily recovered by a magnet, showed high efficiency in photocatalytic degradation of IBP, especially at pH = 4.7.