Photodegradation Efficiency Research Articles

Preparation of Manganese Doped Bismuth Oxide for the photocatalytic Degradation of Methylene Blue

The current study describes a unique method for degrading methylene blue dye utilizing Mn-doped Bi2O3 nanoparticles (NPs) exposed to UV light. Bi2O3 nanoparticles (NPs) doped with Mn were produced using a hydrothermal process. Scanning electron microscopy (SEM), energy-dispersive X-ray analysis (EDX), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and were use to characterize the prepared nanoparticles. It was discovered that the band gaps of Mn/ Bi2O3 NPs are 2%, 3%, and 4%, respectively, and are 4.13 eV, 3.92 eV, and 3.77 eV. Functional group identification using Fourier transforms infrared spectroscopy (FT-IR). Mn-doped Bi2O3 nanoparticles were captured in SEM pictures at various magnifications, and the photos clearly display the particles' dual morphologies, cubic and cylindrical. The Mn-doped Bi2O3 particles were found to be crystalline, with mean diameters of 20 nm, according to the XRD data. The photodegradation efficiency of Mn/Bi2O3 at experimental dye concentrations of 2%, 3%, and 4% was determined to be 90.29, 91.6, and 93.16 percent, respectively, over a 150 minute time interval. At the ideal catalyst dosage of 0.2 g and concentration of 40 ppm, a high percentage of dye degradation was observed. Numerous metals have been doped into zinc oxides, although no work has documented doping of Bi2O3 with Mn. Additionally, it was utilized for the first time to look at the deterioration of Methylene Blue dye.

H2O2-assisted photo-electrocatalytic and photocatalytic degradation of methyl violet by CuO-modified TiO2 nanotube arrays

Photoelectrocatalytic degradation is an environmental friendly and efficient technique providing solutions for the dire issue of water pollution. TiO2 nanotubes are widely used as the photocatalyst but its efficiency is restricted by the wide band gap. This study deals with the fabrication of CuO-modified TiO2 nanotubes by electrochemical anodization following the hydrothermal method to enhance the photocatalytic degradation. Optical studies revealed a reduction in the bandgap (2.12 eV) of CuO-modified TiO2 nanotubes, which plays an important role in increasing the photocatalytic activity. The effect of CuO loading on TiO2 nanotubes in photocatalytic degradation as well as the effect of bias and H2O2 on photo-electrocatalytic degradation were studied. In photocatalytic degradation, 0.05 M CuO–TiO2 photocatalyst produced a maximum degradation of 49.5 % in 8 h. Compared with the pristine TiO2 nanotubes, the photodegradation of CuO-loaded TiO2 nanotubes increased by 16 %. Furthermore, when an external bias was applied, the photodegradation efficiency increased by 36 %. In addition of H2O2 to the PEC system, 0.05 CuO–TiO2 photocatalyst produced 100 % degradation of methyl violet in 2.5 h. Reusability studies showed that the photocatalysts are stable and can therefore be used for practical applications such as photocatalytic degradation and photoelectrochemical degradation of methyl violet.

Enriched photocatalytic degradation of chlorophenols and mineralization of industrial effluents using DUT-8(Zn/Ni)@CeO2 composites

A composite DUT-8(Zn/Ni)αCeO2 photocatalysts were configured using a simple and facile hydrothermal method and characterized using PXRD, SEM, BET, FTIR and Photoluminescence studies to configure their morphological, structural as well spectroscopic characteristics. The as obtained composites demonstrate superior photocatalytic activity for the degradation of dichlorophenols (2, 4 and 2, 6 DCP). The introduction of MOF into the semiconductor oxide proliferate the photocatalytic activity owing to a strong interface between the two that promotes the transfer as well as the separation of photo generated charge carriers. These nanocomposites DUT-8(Zn)@CeO2 and DUT-8(Ni)@CeO2 appear highly promising then the individual counterparts as they record the photodegradation efficiency of (86%, 89%) for 2,4-DCP, and (85%, 91%) for 2,6-DCP respectively at optimal conditions (concentration of pollutants-5 mg/L; catalyst dose-0.6 g/L and pH-8). The practical applicability of the nanocomposites was evaluated using mineralization study involving the industrial effluents of the paper mill industry. Notably, the mineralization of chlorophenols (85.3% for 2,4-DCP, and 87% for 2,6-DCP) was observed in case of DUT-8(Zn)@CeO2 and DUT-8(Ni)@CeO2 nanocomposites. Besides, the synthesized photocatalysts show high stability and reusability for over five experimental cycles.

Ti-doped synergistic hollow thin-walled Bi2O3 nano-microspheres for efficient tetracycline hydrochloride photodegradation

Bismuth oxide (Bi2O3) has been extensively investigated in the fields of environmental photocatalysis, owing to its exceptional charge transport performance and remarkable resistance to photocorrosion. However, the limited absorption spectrum of light and rapid recombination of photogenerated charge results in a low quantum efficiency. Herein, an efficient photocatalytic system for tetracycline hydrochloride (TCH) photodegradation based on titanium (Ti)-doped hollow, thin-walled Bi2O3 with nano-microspheres is fabricated via a facile self-assembly strategy. It is shown that doping Ti in Bi2O3 can generate oxygen vacancies, in addition, the addition of Ti in the solvothermal process inhibits the conversion of Bi3+ to bismuth at high temperature, making the content of each component in the heterostructure controllable. The hybrid catalyst exhibits superior performance in visible-light-driven photocatalytic degradation of TCH (about 95.1 % degradation efficiency after 120 min) and excellent stability (up to 4 cycles) under visible light irradiation. The optimized catalyst exhibits excellent performance in visible light catalytic degradation, owing to the synergistic effect of high specific surface area, Bi plasma resonance effect and charge mobility. Moreover, the photocatalytic mechanism of Ti-Bi2O3 have been deeply analyzed through experimental investigation and DFT theoretical calculations. The findings contribute to the synthesis of efficient visible-light-driven Bi-based photocatalysts and to the understanding of photocatalytic degradation reactions.

Ag-bridged Z-scheme AgI/NU-1000 heterojunction for enhanced photocatalytic degradation of sulfamethazine: Pathways, mechanism insight, and DFT calculations

Constructing heterojunction structures is a crucial approach for improving carrier separation efficiency and expanding the visible-light absorption range of photocatalysts. Herein, a series of Ag-bridged Z-scheme (AgI/NU-1000) heterojunction photocatalysts were successfully prepared using a simple in-situ precipitation method. The photodegradation efficiency of the AgI/NU-1000 samples was assessed by degrading sulfamethazine under visible-light conditions. The optimized AgI/NU-10000.35 (AN-2) photocatalyst exhibited exceptional photodegradation activity, achieving a degradation rate of 89.68 % within 40 min. The toxicity test results proved that the solution degraded by AN-2 exhibited no detrimental effects on biological growth, thereby demonstrating its potential practical application value. Electrochemical and photochemical tests demonstrated that the creation of a Z-scheme heterojunction was favorable for the separation of photogenerated carriers. Density functional theory (DFT) calculations and X-ray photoelectron spectroscopy were used to clarify the electron migration direction within the AgI/NU-1000 heterojunction. Possible degradation pathways and mediate products were investigated using high-performance liquid chromatography–mass spectrometry and DFT calculations. This work demonstrates the potential application of AgI/NU-1000 composite materials in environmental treatment.

Interface-assisted synthesis of Ag/Ceria composites for the detection and photodegradation of organic dyes

A simple method for creating Ag/CeO2 composites involves the reaction between components of an aqueous salt solution and ammonia vapor at the gas-solution interface. The concentrations of the reagents and the reaction time determine the structure and composition of the composite films formed on the solution surface. When the concentration ratio AgNO3/Ce(NO3)3 in the solution is 1/1, a composite film is formed consisting of Ag nanowires and Ceria nanoflakes. A model of the interaction at the liquid-gas interface is proposed. Ag/CeO2 composites have dual capabilities, enabling efficient photodegradation of Methylene Blue organic molecules and improved SERS detection of Rhodamine 6 G dye at concentrations as low as 10−9 mol/L. The synergistic effect of composition and morphology on properties was observed for the composites obtained within 7 minutes of interaction.

Green biosynthesized N-doped CuO@Zeolite nanocomposite for the efficient photodegradation of toxic organic pollutants from wastewater

Nanotechnology is one of the most advanced methods available for the degradation of toxic pollutants from the environment. Specifically, nanoparticles generated with plant extracts are more stable and biocompatible than those produced using traditional chemical and physical processes. The current study focuses on the green synthesis of N-CuO@Zeolite nanocomposite with Camellia sinensis (green tea) leaf extract. The green synthesized nanocomposite was used for the photocatalytic degradation of hazardous organic pollutants, including Auramine-O (AO) and yellow color textile industrial dye (YD). Under direct sunlight irradiation, synthesized nanomaterials exhibited excellent photocatalytic activity for AO and YD degradation. The best conditions for photocatalytic degradation were found to be pollutant concentrations of 2 mg L−1 for AO and 6 mg L−1 for YD, photocatalyst dosages of 15 mg for both AO and YD, and neutral pH for both pollutants. Within 150 minutes, the synthesized N-CuO@zeolite nanocomposite attained degradation efficiencies of 95 % for AO and 92 % for YD, compared to its parent materials N-CuO (80 % for AO and 76 % for YD) and CuO (68 % for AO and 65 % for YD). The degradation rates of both pollutants were accurately described by first-order kinetics, consistent with the Langmuir adsorption model. Additionally, the ecologically sustainable novel N-CuO@Zeolite nanocomposite illustrated superior reliability and reusability, keeping photocatalytic efficiency even after ten cycles of constant utilization, and its long-term stability was confirmed by PXRD analysis after processing. The material's excellent reusability and stability emphasize the nanocomposite's potential as a long-term solution for industrial wastewater treatment applications.

Photocatalytic activity of molybdenum disulfide nanotube arrays with different wall thicknesses under visible light

Light trapping based on nanostructure has emerged as an effective method to improve light absorption of the photocatalytic devices. Herein, molybdenum disulfide nanotube arrays with different wall thicknesses were successfully synthesized by changing reactant concentration from 50 % to 150 %. The nanotubes overcame aggregation of the nanosheets, offered multiple scattering centers and enabled multiple refraction of light, leading to excellent light harvest in the visible range and molecule absorption efficiency as high as 21.0 %. The photodegradation efficiency of methylene blue as catalyzed by the nanotubes was modulated by the wall thickness, in which the highest degradation efficiency of 69.6 % and the largest kinetic constant of 5.516×10−3min−1·cm−2 were achieved for the thinnest wall. The analysis revealed that the photocatalytic activity of the nanotube arrays was dominated by the dye absorption, environment, light excitation and charge recombination, which would provide structural design for their applications in optoelectronics and photocatalysis.

One-Pot Phyto-Mediated Synthesis of Fe2O3/Fe3O4 Binary Mixed Nanocomposite Efficiently Applied in Wastewater Remediation by Photo-Fenton Reaction

A binary Fe2O3/Fe3O4 mixed nanocomposite was prepared by phyto-mediated avenue to be suited in the photo-Fenton photodegradation of methylene blue (MB) in the presence of H2O2. XRD and SEM analyses illustrated that Fe2O3 nanoparticles of average crystallite size 8.43 nm were successfully mixed with plate-like aggregates of Fe3O4 with a 15.1 nm average crystallite size. Moreover, SEM images showed a porous morphology for the binary Fe2O3/Fe3O4 mixed nanocomposite that is favorable for a photocatalyst. EDX and elemental mapping showed intense iron and oxygen peaks, confirming composite purity and symmetrical distribution. FTIR analysis displayed the distinct Fe-O assignments. Moreover, the isotherm of the developed nanocomposite showed slit-shaped pores in loose particulates within plate-like aggregates and a mesoporous pore-size distribution. Thermal gravimetric analysis (TGA) indicated the high thermal stability of the prepared Fe2O3/Fe3O4 binary nanocomposite. The optical properties illustrated a narrowing in the band gab (Eg = 2.92 eV) that enabled considerable absorption in the visible region of solar light. Suiting the developed binary Fe2O3/Fe3O4 nanocomposite in the photo-Fenton reaction along with H2O2 supplied higher productivity of active oxidizing species and accordingly a higher degradation efficacy of MB. The solar-driven photodegradation reactions were conducted and the estimated rate constants were 0.002, 0.0047, and 0.0143 min−1 when using the Fe2O3/Fe3O4 nanocomposite, pure H2O2, and the Fe2O3/Fe3O4/H2O2 hybrid catalyst, respectively. Therefore, suiting the developed binary Fe2O3/Fe3O4 nanocomposite and H2O2 in photo-Fenton reaction supplied higher productivity of active oxidizing species and accordingly a higher degradation efficacy of MB. After being subjected to four photo-Fenton degradation cycles, the Fe2O3/Fe3O4 nanocomposite catalyst still functioned admirably. Further evaluation of Fe2O3/Fe3O4 nanocomposite in photocatalytic remediation of contaminated water using a mixture of MB and pyronine Y (PY) dyestuffs revealed substantial dye photodegradation efficiencies.

Eco-Friendly g-C3N4/Carboxymethyl Cellulose/Alginate Composite Hydrogels for Simultaneous Photocatalytic Degradation of Organic Dye Pollutants.

The presented study was focused on the simple, eco-friendly synthesis of composite hydrogels of crosslinked carboxymethyl cellulose (CMC)/alginate (SA) with encapsulated g-C3N4 nanoparticles. The structural, textural, morphological, optical, and mechanical properties were determined using different methods. The encapsulation of g-C3N4 into CMC/SA copolymer resulted in the formation of composite hydrogels with a coherent structure, enhanced porosity, excellent photostability, and good adhesion. The ability of composite hydrogels to eliminate structurally different dyes with the same or opposite charge properties (cationic Methylene Blue and anionic Orange G and Remazol Brilliant Blue R) in both single- and binary-dye systems was examined through adsorption and photocatalytic reactions. The interactions between the dyes and g-C3N4 and the negatively charged CMC/SA copolymers had a notable influence on both the adsorption capacity and photodegradation efficiency of the prepared composites. Scavenger studies and leaching tests were conducted to gain insights into the primary reactive species and to assess the stability and long-term performance of the g-C3N4/CMC/SA beads. The commendable photocatalytic activity and excellent recyclability, coupled with the elimination of costly catalyst separation requirements, render the g-C3N4/CMC/SA composite hydrogels cost-effective and environmentally friendly materials, and strongly support their selection for tackling environmental pollution issues.

Coumarin-Based Photodegradable Hydrogels Enable Two-Photon Subtractive Biofabrication at 300 mm s-1.

Spatiotemporally controlled two-photon photodegradation of hydrogels has gained increasing attention for high-precision subtractive tissue engineering. However, conventional photolabile hydrogels often have poor efficiency upon two-photon excitation in the near-infrared (NIR) region and thus require high laser dosage that may compromise cell activity. As a result, high-speed two-photon hydrogel erosion in the presence of cells remains challenging. Here we introduce the design and synthesis of efficient coumarin-based photodegradable hydrogels to overcome these limitations. A set of photolabile coumarin-functionalized polyethylene glycol linkers are synthesized through a Passerini multicomponent reaction. After mixing these linkers with thiolated hyaluronic acid, semi-synthetic photodegradable hydrogels are formed in situ via Michael addition crosslinking. The efficiency of photodegradation in these hydrogels is significantly higher than that in nitrobenzyl counterparts upon two-photon irradiation at 780 nm. A complex microfluidic network mimicking the bone microarchitecture is successfully fabricated in preformed coumarin hydrogels at high speeds of up to 300 mm s-1 and low laser dosage down to 10 mW. Further, we demonstrate fast two-photon printing of hollow microchannels inside a hydrogel to spatiotemporally direct cell migration in 3D. Collectively, these hydrogels may open new avenues for fast laser-guided tissue fabrication at high spatial resolution.

A stable and regenerative TiO2/Bi2MoO6 photocatalyst for highly effective degradation of Rhodamine B and Congo Red

ABSTRACT This research unravels a facile method for synthesising TiO2/Bi2MoO6 photocatalysts and their effective applications in degrading industrial dyes. Initially, Bi2MoO6 was prepared as the substrate, followed by the addition of TiO2 to form the TiO2/Bi2MoO6 composite. The photocatalyst was characterised by powder X-ray diffraction (XRD), scanning electron microscopy with energy-dispersive X-ray spectrometry (SEM-EDS), X-ray photoelectron spectroscopy (XPS), high-resolution transmission electron microscopy (HR-TEM), photoluminescence (PL), and UV-Vis diffuse reflectance spectroscopy (UV-Vis DRS). Its photocatalytic properties were evaluated by dye degradation under various conditions, including different dopant loading amounts, the reaction time, the initial concentration of the dye, and pH values. The results indicated that 50 mg of 15% TiO2/Bi2MoO6 achieved the highest photodegradation efficiency: 98.51% for 50 mL 10 mg L−1 Rhodamine B (RhB) within 100 min in a neutral buffer solution and 90.71% for 50 mL 10 mg L−1 Congo Red (CR) within 80 min in an aqueous solution. This material exerted effectiveness across a wide pH range, with removal rates of RhB exceeding 95.41% in both acidic and alkaline conditions. The degradation process conformed to the pseudo-first-order kinetic model. Radical trapping experiments revealed that the dye degradation mechanism involved ∙ O 2 − and h+. Notably, the synthesised TiO2/Bi2MoO6 photocatalyst demonstrated high stability and reusability, maintaining performance even after four degradation cycles. The TiO2/Bi2MoO6 photocatalyst, with TiO2 as the dopant and Bi2MoO6 as the substrate, demonstrated significant versatility and potential for practical dye degradation applications.

Influence of ZrO2 nanoparticles on the structural and photocatalytic properties of three-dimensional PVA/g-C3N4 polymer films

This study introduces a novel polymer nanocomposite film of polyvinyl alcohol (PVA), carbon nitride (g-C3N4), and zirconia (ZrO2), created via solution casting for effective water remediation of organic dyes. The film shows significant potential for enhancing pollutant removal efficiency and offering a sustainable solution for water reuse. Comprehensive characterization using FTIR, XRD, UV–vis, TGA, and FESEM-EDX indicated strong interfacial interactions among PVA, ZrO2, and g-C3N4. XPS and UV–vis spectroscopy revealed a reduction in the optical energy gap from 4.8 to 3.95 eV, enhancing photocatalytic activity. SEM confirmed uniform dispersion of ZrO2 and g-C3N4 within the PVA matrix. Kinetic studies of methylene blue (MB) degradation under solar irradiation at neutral pH showed rate constants (k) of 0.0032 min−1, 0.0094 min−1, 0.0383 min−1, and 0.0816 min−1 for PVA, PVA/(0.003)ZrO2/g-C3N4, PVA/(0.007)ZrO2/g-C3N4, and PVA/(0.01)ZrO2/g-C3N4, respectively. The corresponding half-life times (t1/2) were 216.6 min, 73.7 min, 18.1 min, and 8.5 min, with photodegradation efficiencies of 10 %, 75.2 %, 90 %, and 95 %. This recyclable nanocomposite polymer, PVA/ZrO2/g-C3N4, shows promise for effective decontamination of organic pollutants in water, presenting an innovative approach for advanced remediation and secure wastewater recycling.This work is crucial for society as it contributes to solving the global challenge of water pollution, ensuring access to clean and safe water.

TiO2/Al-PILC Catalysts Synthesized from a Non-Conventional Aluminum Source of Aluminum and Applied in the Photodegradation of Organic Compounds

AbstractThis study explores the transformative potential of Pillared InterLayered Clays (PILC) derived from non-conventional aluminum sources as catalytic supports in the synthesis of TiO2/catalysts for the efficient photodegradation of organic pollutants in water. Montmorillonite (Mt) and three alumina-pillared montmorillonite (PILC) synthesized using various aluminum sources, were impregnated with titanium to synthesize TiO2/catalysts. The successful synthesis of these materials was confirmed through several characterization techniques such as X-ray diffraction (XRD), N2 adsorption-desorption at -196 ºC, morphological analysis using scanning electron microscopy (SEM) and transmission electron microscopy (TEM), and Energy-Dispersive X-ray Spectrometry (EDX). The photolysis, adsorption, and catalytic behavior of the TiO2/catalysts were studied for the degradation of triclosan (TCS), 2,6-dichlorophenol (2,6-DCP), and bisphenol A (BPA). All synthesized catalysts surpassed the efficacy of commercial anatase, with TiO2/Al-PILC exhibiting superior performance in comparison to TiO2/Mt. Photodegradation was most effective under UV radiation, with TCS demonstrating the highest degradation (approximately 70%). Notably, Al-PILC samples, particularly those synthesized from saline slags, displayed enhanced properties. Among them, TiO2/Al-PILCAE exhibited the highest degradation rates under both UV and visible light, underlining the remarkable potential of saline slags as precursors for Al-PILC synthesis. This study provides valuable insights into the design and development of efficient catalysts for water treatment applications, paving the way for sustainable and effective solutions in the realm of environmental remediation.

Efficient visible light photodegradation of BiVO4:Yb3+/Tm3+ with high content of tetragonal phase

Efficient visible light photodegradation of BiVO4:Yb3+/Tm3+ with high content of tetragonal phase

Tailoring local electron density and molecular oxygen activation behavior via potassium/halogen co-tuned graphitic carbon nitride for enhanced photocatalytic activity

Graphite carbon nitride (g-C3N4) is a promising photocatalyst,but its inadequate reactive sites, weak visible light responsiveness, and sluggish separation of photogenerated carriers hamperthe improvement of photodegradation efficiency. In this work, potassium (K) and halogen atoms co-modified g-C3N4 photocatalysts (CN-KX, X = F, Cl, Br, I) were constructed to adjust the electrical and band structure for enhanced generation of reactive oxygen species. Through an integration of theoretical calculation and experimental exploration, the doping sites of halogen atoms as well as the evolution of crystal, band, and electronic structures were investigated. The results show that a covalent bond is formed between the F atom and the C atom, substitution of the N atom occurs with a Cl atom, and doping of Br, I, or K atoms takes place at the interstitial site. CN-KX photocatalysts exhibits lower band gap, faster photogenerated electron migration, and enhanced photocatalytic activity. Specifically, the CN-KI photocatalyst exhibits the highest photodegradation efficiency because of its smaller interplanar spacing, formation of the midgap state, and adjustable local electron density. Equally, the doping of I atom not only provides a stable adsorption site for oxygen (O2) but also facilitates electron transfer, promoting the production of superoxide radicals (O2−) and contributing to the process of photodegradation.

Enhanced photocatalytic reduction of Cr (VI) using porous hierarchical Bi2O3/Bi2S3 high-low heterojunctions: Novel strategies and charge transfer mechanisms

High-low heterojunctions derived from metal-organic frameworks (MOFs) have promising applications in photocatalytic wastewater treatment because of their high photo-redox ability and boosted charge separation efficiency. Herein, Bi-MOF derived porous hierarchical Bi2O3/Bi2S3 nanoflower-like heterojunctions were prepared by the calcination-hydrothermal method. The optimized Bi2O3/Bi2S3-2 composite showed a higher degradation rate of Cr (VI) (99.79 % in 30 min) than the pure substance. Moreover, comprehensive studies were conducted on the kinetics, stability and recycling of Bi2O3/Bi2S3, as well as optical characteristics. The active species trapping experiments confirmed that e- plays a dominant role in the elimination of Cr (VI). These findings provided novel strategies for construction of porous hierarchical heterojunctions with advanced visible-light-induced degradation performance. The enhanced photo-degradation efficiency of the optimal nanocomposite was assigned to the higher visible-light absorbance, separation of photogenerated carriers, reduced recombination of photo-induced carriers, and enhanced redox capability owing to the construction of porous hierarchical heterojunctions amongst the components.

Heterojunction composites of covalent organic frameworks grown on the surface of persistent luminescent nanoparticles for photocatalytic hydrogen evolution and degradation of organic pollutants

Covalent organic frameworks (COFs) have shown great promise for photocatalytic hydrogen evolution from water and photocatalytic degradation of organic pollutants. However, a single COFs suffers from poor photogenerated charge separation efficiency. In this study, we synthesized persistent luminescent nanoparticles (PLNPs)@COFs composites with core–shell heterostructures by the in situ growth of COFs on the surface of PLNPs. The PLNPs@COFs composites demonstrated better photocatalytic performance than pure PLNPs and COFs. The hydrogen production rate of PLNPs@COFs (1:6) was about 35 mmol h−1 g−1, and the photodegradation efficiency of Rhodamine B by PLNPs@COFs (3:1) reached 100 % in 50 min. Evidently, the combination of COFs with PLNPs to form a core–shell heterostructure with a tight contact interface can effectively improve the photogenerated charge separation efficiency. Our covalent bonding and in situ growth approach is more conducive to the formation of stable core-shell heterostructures. A good match between the persistent luminescence emission spectrum of the PLNPs and the absorption range of the COFs improves the potential of PLNPs@COFs to function as a round-the-clock photocatalyst. This strategy holds excellent promise in the efficient use of solar photocatalytic hydrogen evolution and in environmental purification in the future.

Construction of a novel OS/BiVO4 catalyst for enhancing the photocatalytic degradation performance of sulfonamide

Exploiting of high-value-added environmental materials related to oily sludge (OS) is an important development direction for OS resource utilization. A series of OS/BiVO4 catalysts were synthesized by activation-pyrolysis and hydrothermal methods. Photocatalytic performance was estimated through sulfanilamide (SA) degradation (SA) under visible light irradiation. The OS/BiVO4–20% has the best photodegradation ability for SA. The degradation rate of SA was about 97.8% after six hours of visible light irradiation. The first-order kinetics degradation rate constants of OS/BiVO4–20% for SA is 8.3 times that of pure BiVO4. The radical quenching and ESR experiments reveal that the hole (h+) and hydroxyl radical (·OH) were the primary active species for SA photocatalytic degradation. The presence of OS and H2O2 can significantly improve the charge separation efficiency, and inhibit electron-hole complexes, thereby extending the lifetime of electron carriers and producing many active hydroxyl radicals and holes on the surface of catalyst particles. Due to the introduction of OS, OS/BiVO4 has good texture properties and high oxygen absorption content, which is also conducive to the photodegradation of SA. Fourier-transform infrared (FTIR), in combination with two-dimensional correlation spectroscopy (2D-COS), indicated that the C–N (1351 cm-1), CC (1450 cm-1), SO2–N (1116 or 1182 cm-1), and N–H (1636 cm-1) groups can change in turn during the catalytic degradation process. This work improves the surface properties of BiVO4 semiconductor materials by introducing OS, thereby increasing the photodegradation efficiency of BiVO4 catalysts against antibiotics, which provides valuable insights into the design of next-generation photocatalysts.

Ionic liquid based surfactant-free microemulsion as a new protocol for preparation of visible light active poly(methyl methacrylate)/TiO2 nanocomposite

The practical application of sensitized TiO2 nanocomposites is very satisfying due to their high photon utilization in visible light, simple recovery without affecting the photocatalytic performance, high energy efficiency, low potential environmental risk, and low operational costs. The objective of this study is developing the ionic liquid (IL)-based surfactant-free microemulsion, as a soft template, for preparation of a novel type of sensitized poly(methyl methacrylate)/TiO2 nanocomposite (PMMA/TiO2/IL). For this purpose, a series of visible light-responsive PMMA/TiO2/IL transparent nanocomposites were prepared in microemulsion composed of methyl methacrylate monomer, 1-buthyl-3-methylimidazolium tetrafluoroborate ([bmim][BF4]), and 1-buthanol as amphi-solvent. Techniques such as diffuse reflectance spectroscopy (DRS)), attenuated total reflectance-fourier transform infrared (ATR-FTIR) spectroscopy, atomic force microscopy (AFM), field emission scanning electron microscopy (FE-SEM), and energy dispersive X-ray analysis (EDX) were used to characterize prepared nanocomposites. Photocatalytic degradation of methyl orange dye under visible light illumination, as an application in wastewater treatment, with the investigation of the influence of TiO2 content in the nanocomposite, pH, and nanocomposite reusability on photodegradation efficiency was studied and maximum value of 93.9% obtained at optimum conditions. The FESEM analysis indicated that the utilization of a relatively low amount of ionic liquid and also in absence of the surfactant ensures the monodispersity of the visible light sensitized TiO2 nanoparticles in the polymer matrix.