Photocatalytic Degradation Of Pollutants Research Articles

Ultrathin NCDs/BiOBr with oxygen vacancies for efficient photocatalytic degradation of tetracyclines: Revealing the triple role of NCDs in the synthesis

Photocatalytic degradation of organic pollutants is a widely used technology. Constructing oxygen vacancies, compounding other materials, and adjusting semiconductor morphology are effective ways to promote the performance of photocatalysis. In this study, ultrathin NCDs/BiOBr nanosheets with excellent photocatalytic ability were prepared. The triple role of NCDs in NCDs/BiOBr synthesis was revealed: controlling the thickness of the nanosheets, increasing the oxygen vacancy concentration, and regulating the band gap structure. Rhodamine B and tetracycline were degraded by the samples in visible light to examine their photocatalytic properties. The samples with the highest electron transfer efficiency were verified by optical and electrochemical characterization. As-synthesized NCDs/BiOBr catalysts exhibited good degradation in different water samples，indicating the ability of the samples for practical applications. In addition, the intermediates and possible degradation pathways of the prepared catalysts for the degradation of TC processes were also analyzed in depth. The electron transfer pathway and photocatalytic mechanism of NCDs/BiOBr were proposed in combination with free radical detection and energy band calculation.

Efficient Adsorption and Photocatalytic Degradation of Organic Pollutant by Ag3PO4/ZnO/Chitosan–Biochar Composites

Efficient Adsorption and Photocatalytic Degradation of Organic Pollutant by Ag3PO4/ZnO/Chitosan–Biochar Composites

Effect of ligand substitution in UiO-66 metal-organic frameworks on the photocatalytic oxidation of acetaldehyde

A series of functionalized X-UiO-66 (X = NH2, H, Br and NO2) materials were prepared using a hydrothermal method and modified with various ligands. Their photocatalytic activity was evaluated by the oxidation of acetaldehyde. Experimental results show that the introduction of different ligands significantly influences the physicochemical properties of UiO-66. Br-UiO-66 exhibited the highest photocatalytic activity and CO2 selectivity of 85.6% and 85.7%, respectively. Photochemical properties reveal that -Br functional group facilitate the separation of photogenerated electrons and holes, significantly improving their transfer and oxygen reduction. As a result, an increased number of hydroxyl and superoxide radicals can form, improving the efficiency of the photocatalytic reaction. Br-UiO-66 accumulates fewer intermediates on its surface and still shows excellent photocatalytic activity and structural stability after 24 h of dynamic reaction. This work demonstrates the excellent adsorption and catalytic oxidation performance of Br-UiO-66 towards acetaldehyde and may provide new ideas for researching catalysts in the photocatalytic degradation of pollutants.

Recent Developments in Semiconductor-Based Photocatalytic Degradation of Antiviral Drug Pollutants.

The prevalence of antiviral drugs (ATVs) has seen a substantial increase in response to the COVID-19 pandemic, leading to heightened concentrations of these pharmaceuticals in wastewater systems. The hydrophilic nature of ATVs has been identified as a significant factor contributing to the low degradation efficiency observed in wastewater treatment plants. This characteristic often necessitates the implementation of additional treatment steps to achieve the complete degradation of ATVs. Semiconductor-based photocatalysis has garnered considerable attention due to its promising potential in achieving efficient degradation rates and subsequent mineralization of pollutants, leveraging the inexhaustible energy of sunlight. However, in recent years, there have been few comprehensive reports that have thoroughly summarized and analyzed the application of photocatalysis for the removal of ATVs. This review commences by summarizing the types and occurrence of ATVs. Furthermore, it places a significant emphasis on delivering a comprehensive summary and analysis of the characteristics pertaining to the photocatalytic elimination of ATVs, utilizing semiconductor photocatalysts such as metal oxides, doped metal oxides, and heterojunctions. Ultimately, the review sheds light on the identified research gaps and key concerns, offering invaluable insights to steer future investigations in this field.

Influence of doping with Co, Cu and Ni on the morphological and structural parameters and functional properties of ZnO nanoobjects

Recently, ZnO nanoobjects (nanoparticles, nanosheets, nanorods, nanoflowers, etc.) have been extensively studied due to their unique dielectric, optical and photocatalytic properties. Appearing on a nanoscale, these properties make ZnO nanoobjects a promising material in optoelectronics, photocatalytic degradation of cyclic pollutants in wastewater and other applications. Introducing 3d elements into the ZnO lattice not only results in appearing additional levels in the band gap, but also significantly impacts the process of nanoobject formation. While many works were devoted to the former issue, the latter has not been fully studied yet, which determined the direction of this work.In this context, we obtained undoped and Cu-, Co- and Ni-doped ZnO nanoobjects by the precipitation method. To study morphological and structural parameters of the samples obtained, they were characterised by a set of methods (XRD, SEM, FTIR, AES-ICP, SSA, XPS, Raman and absorbance spectroscopy). The developed approach was used in order to evaluate the amount of oxygen vacancies and defects in (un)doped ZnO from XPS and Raman spectra. As for functional properties, impedance spectroscopy as well as photoluminescence and photocatalytic activity studies were conducted.In this work, it was discovered that crystallite sizes become greater for doped ZnO nanoobjects and their values depend on the dopant hydroxo complex equilibrium constants. Doping changes a shape of nanoobjects: ZnO, Cu–ZnO and Ni–ZnO are nanosheets of different thickness, but Co–ZnO has a shape of nanoflowers. Oxygen vacancy and defect amount also changes in case of doped samples. As for functional properties, doping leads to an increase of photoluminescence, reduces ZnO nanoobjects’ dielectric losses and enhance photodegradation velocity of methylene blue.The results of the comprehensive study reveal the possibility of changing morphological, structural and consequently, functional parameters of ZnO nanoobjects by varying the chemical nature of the dopant. This leads to new opportunities in developing materials with desired properties.

Rational construction of g-C3N4/SnO2/CoFe2O4 dual Z-scheme system as a potential scaffold for fluorescence sensing and visible light driven photocatalytic degradation of lethal pollutants

Mimicking the natural photosynthesis process, novel direct dual Z-scheme CN/SnO2/CoFe2O4 heterostructures with different weight ratios (CN/SnO2:CoFe2O4 be 1:1, 2:1 and 1:2; namely CSnCo-1, CSnCo-0.5 and CSnCo-2, respectively) were successfully fabricated and employed for photocatalytic degradation of anthracycline drug, doxorubicin (DXR) and aromatic compound, p-nitrophenol (PNP) and fluorescence detection of heavy metal ion, Hg2+; DXR and PNP. CSnCo-0.5 displayed exceptional photocatalytic capability having pseudo first order rate constant values 5.60, 3.02, 1.23 and 1.38 times higher for DXR; and 4.2, 3.0, 1.18 and 1.12 times higher for PNP in comparison to CN, CSn-20, CSnCo-1 and CSnCo-2, respectively. UV–vis DRS study, photoluminescence spectra and electrochemical impedance results inveterate the formation of direct dual Z-scheme charge transfer, which is beneficial for boosting photocatalytic performance of the system. Additionally, CSnCo-0.5 proved to be highly selective and sensitive for the FL sensing of Hg2+, DXR and PNP with detection limits as low as 0.57 µM, 0.05 µM and 0.63 µM, respectively. Further, sensor provided good analytical performance in real water samples.

Hydrothermal Synthesis of Heterostructured g-C3N4/Ag-TiO2 Nanocomposites for Enhanced Photocatalytic Degradation of Organic Pollutants.

In this study, heterostructured g-C3N4/Ag-TiO2 nanocomposites were successfully fabricated using an easily accessible hydrothermal route. Various analytical tools were employed to investigate the surface morphology, crystal structure, specific surface area, and optical properties of as-synthesized samples. XRD and TEM characterization results provided evidence of the successful fabrication of the ternary g-C3N4/Ag-TiO2 heterostructured nanocomposite. The heterostructured g-C3N4/Ag-TiO2 nanocomposite exhibited the best degradation efficiency of 98.04% against rhodamine B (RhB) within 180 min under visible LED light irradiation. The g-C3N4/Ag-TiO2 nanocomposite exhibited an apparent reaction rate constant 13.16, 4.7, and 1.33 times higher than that of TiO2, Ag-TiO2, and g-C3N4, respectively. The g-C3N4/Ag-TiO2 ternary composite demonstrated higher photocatalytic activity than pristine TiO2 and binary Ag-TiO2 photocatalysts for the degradation of RhB under visible LED light irradiation. The improved photocatalytic performance of the g-C3N4/Ag-TiO2 nanocomposite can be attributed to the formation of an excellent heterostructure between TiO2 and g-C3N4 as well as the incorporation of Ag nanoparticles, which promoted efficient charge carrier separation and transfer and suppressed the rate of recombination. Therefore, this study presents the development of heterostructured g-C3N4/Ag-TiO2 nanocomposites that exhibit excellent photocatalytic performance for the efficient degradation of harmful organic pollutants in wastewater, making them promising candidates for environmental remediation.

In situ construction of Z-type defective Al2O3/BiPO4 for efficient photocatalytic degradation of organic dyes

In this study, we synthesize an Al2O3/BiPO4 heterojunction via a straightforward in-situ coprecipitation technique. An examination of the catalyst specimen reveals that Al2O3 nanoparticles are uniformly distributed on the surface of the hexagonal BiPO4, achieved through the formation of sturdy chemical bonds. This process leads to the creation of an Al2O3/BiPO4 heterojunction with an elevated concentration of oxygen vacancies. This, in turn, contributes to a notable decrease in the photocatalyst's energy band gap while enhancing the absorption spectrum for visible light. Additionally, the Al2O3/BiPO4 complex showcases a unique internal electric field, giving rise to a direct Z-type heterostructure. This heterostructure can drive the selective migration of photogenerated electrons and holes, achieve effective separation of photogenerated charges under the synergistic effect of oxygen vacancies, and maintain the strong redox abilities of BiPO4 and Al2O3. Consequently, there has been a marked improvement in the efficiency of photocatalytic degradation of organic pollutants in dyes.

Simple ultrasonic integration of shapeable, rebuildable, and multifunctional MIL-53(Fe)@cellulose composite for remediation of aqueous contaminants

Metal-organic frames (MOFs) have been recognized as one of the best candidates in the remediation of aqueous contaminants, while the fragile powder shape restricts the practical implementation. In this work, a shapeable, rebuildable, and multifunctional MOF composite (MIL-53@CF) was prepared from MIL-53 (Fe) and cellulose fiber (CF) using a simple ultrasonic method for adsorption and photocatalytic degradation of organic pollutants in wastewater. The results showed MIL-53(Fe) crystals were uniformly growth on CF surfaces and bonded with surface nanofibrils of CF through physical crosslinking and hydrogen bonding. Because of the high bonding strength, the MIL-53@CF composite exhibited an excellent compressive strength (3.53 MPa). More importantly, the MIL-53@CF composite was rebuildable through mechanical destruction followed by re-ultrasonication, suggesting the excellent reusability of MIL-53@CF for water remediation. The MIL-53@CF composite also had high adsorption capacities for methyl orange (884.6 mg·g−1), methylene blue (198.3 mg·g−1), and tetracycline (106.4 mg·g−1). MIL-53@CF composite could degrade TC through photocatalysis. The photocatalytic degradation mechanism was attributed to the Fe(II)/Fe(III) transform cycle reaction of MIL-53 crystal located on MIL-53@CF. Furthermore, the mechanical property and remoldability of MIL-53@CF composite increased its practicability. Comprehensively, MIL-53@CF composite provided a possible strategy to practically apply MOF in the remediation of aqueous contaminants.

Recent advancement in NiFe2O4-based nanocomposites for the photocatalytic degradation of pollutants in aqueous solutions: a comprehensive systematic review

Abstract Nanocomposites with diameters of 1 to 100 nm have modified properties such as uniform size distribution, small size, high surface-to-volume ratio, high absorbability, porosity, and various potential roles, including in catalytic and biological activities. The purpose of this research study was to systematically review all research studies on the photocatalytic decomposition of pollutants by NiFe2O4-based nanocomposites and evaluate the optimal laboratory conditions and the results of these studies. The present systematic review was conducted by searching Scopus, PubMed and Web of Science databases until March 2022. The parameters of nano catalyst type and size, synthesis methods, pollutant type, optimal pH, optimal initial pollutant concentration, optimal catalyst concentration, optimal time, radiation and removal efficiency were investigated. 454 studies were screened and using the inclusion and exclusion criteria, in total, 31 studies met our inclusion criteria and provided the information necessary to photocatalytic degradation of pollutants by NiFe2O4-based nanocomposites. In the investigated studies, the percentage of photocatalytic degradation of pollutants by NiFe2O4-based nanocomposites was reported to be above 70%, and in some studies, the removal efficiency had reached 100%. From the results of this systematic review, it was concluded that the photocatalytic process using NiFe2O4-based nanocomposites has a high effect on the degradation of aqueous solution pollutants.

Effect of the supramolecular material constructed by organic cations and AgI as a catalyst for tetracycline treatment

As a class of materials with novel structures and good functionality, supramolecular compounds are frequently used for photocatalytic degradation of organic pollutants. On this basis, three new supramolecular materials {[L1]·[Ag5I8]}n (1), {[(L2)·(Ag5I8)]·DMF}n (2) and {[L3]·[Ag6I9]}n (3) were synthesized by solution volatilization reaction of three cationic templates 1,3,5-Tris(diethylaminomethyl)-2,4,6-Trimethylphenyl bromide (L1), 1,3,5-Tris(trimethylaminomethyl)-phenyl bromide (L2) and 1,3,5-Tris(1-methylimidazolylmethyl)-2,4,6-trimethylphenyl bromide (L3) with AgI at room temperature, respectively. Compounds 1–3 were characterized by elemental analysis, infrared spectroscopy, UV–vis absorption spectroscopy, and thermometry. The results of single crystal X-ray diffraction analysis show that compounds 1–3 are anion polymers with multinuclear building blocks. As a catalyst, compound 1/H2O2 has a good degradation effect on tetracycline (TC) under visible light irradiation. The adsorption dynamics are best fit by quasi-first order models.

Fabrication of loaded Ag sensitized round-the-clock highly active Z-scheme BiFeO3/Ag/Sr2MgSi2O7:Eu2+,Dy3+/Ag photocatalyst for metronidazole degradation and hydrogen production

To achieve efficient round-the-clock photocatalytic degradation of organic pollutants with simultaneous hydrogen production, Sr2MgSi2O7:Eu2+,Dy3+ with long-afterglow luminescence property and photocatalytic activity was selected to combine with BiFeO3 to construct a novel Z-scheme photocatalytic system. The luminescence intensity of Sr2MgSi2O7:Eu2+,Dy3+ and round-the-clock photocatalytic activity of the Z-scheme BiFeO3/Ag/Sr2MgSi2O7:Eu2+,Dy3+/Ag photocatalyst were enhanced by loading Ag nanoparticles. In the presence of BiFeO3/Ag/Sr2MgSi2O7:Eu2+,Dy3+/Ag photocatalyst, the metronidazole degradation rate and hydrogen production amount were 63.85% and 444.64 μmol/g, respectively, under sunlight irradiation for 240 min, which were approximately 3.39 and 3.63 times as high as ones of BiFeO3 and Sr2MgSi2O7:Eu2+,Dy3+. When the external light was removed for 240 min, the metronidazole degradation rate and hydrogen production amount increased by 9.08% and 57.07 μmol/g, which were 4.12 and 3.15 times as high as ones of BiFeO3 and Sr2MgSi2O7:Eu2+,Dy3+ photocatalysts. This work provides a new research orientation for the design of a highly active Z-scheme photocatalyst for round-the-clock photocatalytic organic pollutants degradation with simultaneous hydrogen production.

Bio-fabricated silver nanocatalyst for photocatalytic degradation and organic transformation of toxic pollutants

Water pollution is major issue in global due rapid industrialization. The release of textile dyes from the industries to the environment has become a significant health issue to humans, trees and animals. The work describes the green synthesis of Mexican mint leaves plant derived silver nanoparticles (MM-AgNPs). The synthesized MM-AgNPs was well characterized by several techniques. MM-AgNPs used as photocatalytic degradation of toxic dyes and catalytic transformation of 4-nitrophenol into 4-aminophenol. Interestingly, Toluidine blue, Congo red, Pyronine Y dye, after mixing with NaBH4 and MM-AgNPs were completely decolorized. The degradation efficiency was calculated for each dye and kinetic parameters. Also, MM-AgNPs act good catalyst for the decolorized of dyes from industrial wastewater and degradation mechanism was proposed. Further synthesized MM-AgNPs applied as a catalyst for the reduction of 4-nitrophenol to 4-aminophenol within 8 min. Finally, this work is more suitable for the good photocatalytic degradation and reduction in the filled of interdisciplinary material science and environmental science.

Durable Co(OH)2/stearic acid-based superhydrophobic/superoleophilic nanocellulose membrane for highly efficient oil/water separation and simultaneous removal of soluble dye

The discharge of industrial oily wastewater is threats to the environment. A long-lasting Co(OH)2/stearic acid (STA)-based superhydrophobic/superoleophilic nanocellulose-based membrane (SSNM) for extremely effective oil/water and simultaneous removal of soluble dye was created to offer solutions to this problem. The mechanical durability of the prepared Co(OH)2/STA-based SSNMs was reinforced by depositing Co(OH)2 and STA on the cellulose fibers. The Co(OH)2/STA-based SSNM shows a high water contact angle of 164 ± 2° and an oil contact angle of ∼0°, exhibiting excellent superhydrophobicity and superoleophilicity. With good usage stability, high separation efficiencies (>94.0%) and high separation fluxes (>130 L·m−2·h−1) were achieved for four oils. The separation flux and efficiency of N-hexane did not change obviously after repeated separation. Furthermore, it exhibited reliable photocatalytic ability, which contributed to the reduction of organic contamination. As a result, Co(OH)2/STA-based SSNM shows strong potential for practical applications such as oil/water separation and photocatalytic degradation of organic pollutants.

Tailored synthesis of a novel silver-decorated l-cysteine-modified graphene oxide nanohybrid with enhanced photocatalytic and antibacterial performances

Noteworthy, potential materials such as l-cysteine and Ag nanoparticles display promising and favorable features in target applications. In the present study, a novel nanohybrid containing l-cysteine-modified graphene oxide (CysGO) decorated with silver nanoparticles (Ag/CysGO) was facilely fabricated through an ultrasound route and characterized by multiple techniques. The antibacterial activity of CysGO and Ag/CysGO nanomaterials was investigated separately for gram-positive and gram-negative bacteria degradation. Owing to the significant antibacterial properties of Ag nanoparticles, Ag/CysGO demonstrated remarkable antibacterial performance for different bacteria. Ag/CysGO also was utilized for the photocatalytic degradation of MB pollutants to corresponding safe materials. Kinetic evaluations for the photocatalytic degradation of MB over prepared catalysts under visible light illumination have been investigated. Based on the reusability tests, the prepared nanohybrid demonstrates the reusability activity without a substantial activity loss. Overall, Ag/CysGO nanohybrid can be an efficient nanomaterial for environmentally friendly photocatalytic degradation approaches.

Biomass-derived activated carbon nanocomposites for cleaner production: A review on aspects of photocatalytic pollutant degradation

Nowadays, water contamination resulting from the disposal of industrial and urban waste poses a significant threat to marine life and human. Hence, providing an effective treatment approach to reduce the total cost and duration of the wastewater treatment process is crucial. Although the adsorption and photocatalysis methods show superb potential for removing hazardous pollutants from water, their combination through a suitable synthesis route is one of the most effective ways to overcome their limitations. Activated carbon (AC) significantly accelerates the rate of pollutant degradation for AC-based photocatalysts compared to bare photocatalysts because of its ability to increase the number of attachment sites, strengthen the interaction between pollutants and photocatalysts, and facilitate rapid electron transfer to prevent electron or hole recombination. This study aims to investigate four main objectives: 1) evaluating key parameters to enhance the surface characterization of AC-derived from lignocellulosic sources using physical and chemical techniques; 2) Surveying various approaches for synthesizing AC-based photocatalysts; 3) explaining the mechanism of photocatalytic degradation of pollutants and the operating parameters in the wastewater treatment process; and 4) providing an overview of the opportunities, challenges, suggestions, and potential future outlooks. Future studies should focus on understanding the structural properties of AC to design effective photocatalytic systems for degrading hazardous contaminants. Generally, AC-based nanocomposites reduce both process costs and duration and promote environmental sustainability by effectively eliminating pollutants.

A Pragmatic Review on Bio-polymerized Metallic Nano-Architecture for Photocatalytic Degradation of Recalcitrant Dye Pollutants

A Pragmatic Review on Bio-polymerized Metallic Nano-Architecture for Photocatalytic Degradation of Recalcitrant Dye Pollutants

Photothermal-Assisted Photocatalytic Degradation of Tetracycline in Seawater Based on the Black g-C3N4 Nanosheets with Cyano Group Defects

As a broad-spectrum antibiotic, tetracycline (TC) has been continually detected in soil and seawater environments, which poses a great threat to the ecological environment and human health. Herein, a black graphitic carbon nitride (CN-B) photocatalyst was synthesized by the one-step calcination method of urea and phloxine B for the degradation of tetracycline TC in seawater under visible light irradiation. The experimental results showed that the photocatalytic degradation rate of optimal CN-B-0.1 for TC degradation was 92% at room temperature within 2 h, which was 1.3 times that of pure CN (69%). This excellent photocatalytic degradation performance stems from the following factors: (i) ultrathin nanosheet thickness reduces the charge transfer distance; (ii) the cyanogen defect promotes photogenerated carriers’ separation; (iii) and the photothermal effect of CN-B increases the reaction temperature and enhances the photocatalytic activity. This study provides new insight into the design of photocatalysts for the photothermal-assisted photocatalytic degradation of antibiotic pollutants.

Recent Advances in MXenes Based Composites as Photocatalysts: Synthesis, Properties and Photocatalytic Removal of Organic Contaminants from Wastewater

AbstractMXene has indeed gained significant attention in recent years as a promising photocatalyst for various applications, including photocatalytic degradation of pollutants. MXene possesses several unique physical and chemical properties that make it suitable for such applications, including its uniform planar structure, strong metal conductivity, effective functional groups, and numerous derivatives. These properties contribute to the excellent photodegradation performance and long‐term stability exhibited by MXene‐based photocatalysts compared to other photocatalysts. MXene‐based composites, which are formed by incorporating MXene with other materials, demonstrate even better photodegradation activity due to their abundant active sites and porous structure. One crucial factor influencing the photodegradation performance of MXene‐based photocatalysts is the presence of active functional groups on the surface of MXene. These functional groups play a significant role in the photocatalytic process and contribute to the overall efficiency of the catalyst. To provide a broader understanding of MXene‐based photocatalysts, the physicochemical properties of MXene are briefly described in this review. This includes its structural characteristics, electrical conductivity, and the presence of functional groups. This review also investigates the physical and chemical synthesis routes for preparing MXene, both in its natural state and as composites with other materials. These synthesis methods are essential for tailoring the properties of MXene‐based photocatalysts to meet specific requirements. Finally, the review discusses future work and challenges in MXene‐based photocatalysis. This field holds great promise for addressing environmental concerns and improving the degradation of organic compounds. However, further research is needed to optimize the synthesis methods, enhance the photocatalytic efficiency, and explore the practical applications of MXene‐based photocatalysts.

Selective surface enhanced Raman detection and effective photocatalytic degradation of sulfonamides antibiotic based on a flexible three-dimensional chitosan/carbon nitride/silver substrate

The prevalence of sulfonamide residues in aquatic environments poses serious environmental risks, and the sensitive detection and effective degradation of sulfonamides have attracted widespread attention. Here, the environmentally friendly chitosan (CS)/carbon nitride (CN) with three-dimensional porous structure is fabricated by freeze-drying method, and subsequently a new bifunctional flexible substrate (CS/CN/Ag) is prepared by anchoring of small sized AgNPs (6 ∼ 12 nm) on CS/CN. Importantly, the CS/CN/Ag substrate shows high adsorption capacity (∼ 83.06%) for sulfamethoxazole (SMX) solution within 20 mins and the limit of detection can be as low as 7.46 × 10−9 mol·L−1 with an enhancement factor of 3.3 × 105. Also, the CS/CN/Ag substrate displays highly selective for surface-enhanced Raman spectroscopy (SERS) detection of sulfonamides and also shows excellent SERS response for SMX in hospital wastewater samples. In addition, the photocatalytic degradation efficiency of SMX could reach as high as 99.22% within 20 mins of irradiation and the CS/CN/Ag still maintains outstanding photocatalytic performance after six cycles. Moreover, the Ag content in the CS/CN/Ag substrate is only 2.35%, and also the CS/CN/Ag exhibits good uniformity, repeatability, recyclability and stability. Therefore, this flexible and cost-effectively substrate of CS/CN/Ag shows great potential for the simultaneous SERS detection and photocatalytic degradation of pollutants in actual wastewater samples.