Photodegradation Of Methylene Blue Research Articles

A Facile Microwave-Promoted Formation of Highly Photoresponsive Au-Decorated TiO2 Nanorods for the Enhanced Photo-Degradation of Methylene Blue

The integration of noble metal nanoparticles (NPs) effectively modifies the electronic properties of semiconductor photocatalysts, leading to improved charge separation and enhanced photocatalytic performance. TiO2 nanorods decorated with Au NPs were successfully synthesized using a cost-effective, rapid microwave-assisted method in H2O2 and HF media for methylene blue (MB) degradation under visible light illumination. X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), transmission electron microscopy (TEM), N2 physisorption, and UV–vis spectroscopy were employed to characterize the structures, morphologies, compositions, and photoelectronic properties of the as-synthesized materials. The fusing of Au NPs effectively alters the electronic structure of TiO2, enhancing the charge separation efficiency and improved electrical conductivity. The HF treatment promotes the exposure of the highly reactive (001) and (101) crystalline facets. The improved photocatalytic activity of Au/TiO2, achieving 97% efficiency, is attributed to the surface plasmon resonance (SPR) effect of the Au NPs and the presence of oxygen vacancies. The photodegradation of MB using the TiO2/Au photocatalysts follows pseudo-first-order kinetics, highlighting the enhanced catalytic efficiency of the synthesized nanostructures. The exceptional properties of the binary Au/TiO2 photocatalysts, including the SPR effect, exposed crystallographic faces, and efficient charge carrier separation through a decrease in the recombination of electrons and holes, contribute to the photocatalytic degradation of MB.

Enhanced photocatalytic properties of TiO2/rGO nanocomposites Doped with CdS

To increase the photocatalytic activity of nanocomposite based on TiO2 and rGO (NC) and improve its photosensitivity in the visible region of the spectrum, the influence of CdS concentration (1 to 10 wt% with respect to NC) on its physicochemical and photocatalytic properties was studied. The addition of CdS to NC leads to a significant increase in the photocatalytic activity. An almost fivefold increase in photocurrent compared to pure NC was registered for NC/CdS_5%. Data on Methylene blue photodegradation showed that after 210 min of irradiation, only 5 % of dye molecules remained in solution. This value is 14.4 and 11.6 times higher than that of pure NC or CdS, respectively. Enhanced photocatalytic activity is related both to the improvement of NC absorption in the region of 400–800 nm and the decrease of the band gap width of NC upon addition of CdS, as well as the significant change in the electrophysical characteristics of the nanocomposite.

Synthesis and Characterization of TiO2 Thin Films Modified with Anderson-Type Polyoxometalates (Ni, Co, and Fe)

In this work, TiO2 and Anderson-type polyoxometalates (Ni, Co, and Fe) thin-film composites were fabricated. The composites were characterized by FTIR and Raman spectroscopy, diffuse reflectance, and scanning electronic microscopy. The methylene blue (MB) photocatalytic degradation on the composites under UV irradiation was studied. Spectroscopic results verified the modification of TiO2 thin films. Optical and morphological properties changed after TiO2 modification. The largest change in the optical band gap was observed for the FePOM/TiO2 system, which reported a value of 3.05 eV. The POM/TiO2 systems were more efficient in methylene blue (MB) adsorption than bare TiO2. Furthermore, the modified films were more efficient than bare TiO2 during MB photodegradation tests. The NiPOM/TiO2 and the CoPOM/TiO2 were the most efficient in the MB adsorption, reaching ~20%. The NiPOM/TiO2 and the CoPOM/TiO2 composites were the most efficient in the photodegradation process, reaching ~50% of MB removal. The stability tests indicated that composite films were moderately stable after the three performed reusability cycles. Thus, these results suggest that POM modification of TiO2 can improve the adsorption and photodegradation capacity of semiconductors.

A study on the influence of metal Ag, Cu, and Fe doping on the morphological, structural, and photocatalytic activity of TiO2 nanostructures

Metal-doped TiO2 nanoparticles (NPs) were elaborated by a sol–gel method using n-butoxide of titanium (IV) as precursors. The resulting NPs were characterized by scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD), Raman spectroscopy, and FTIR analysis. The SEM study shows the formation of a spheres-like structure. The EDX analysis proves the presence of Ag, Fe, and Cu on the doped TiO2 NPs. XRD and Raman spectroscopy analysis show that the doping inhibited the phase transformation and stabilized the anatase phase. The photocatalytic activity of prepared TiO2 NPs was evaluated in methylene blue (MB) photodegradation under UV irradiation. The results reveal that the doped TiO2 NPs were more efficient than undoped TiO2 NPs in the degradation of MB. The Cu-doped TiO2 NPs were found to be more efficient in this reaction with a degradation efficiency of about 92.31 % and a kinetic rate constant of about 10−2 min−1. The studies of the reactive species show that the holes are the main reactive species responsible for the photocatalytic oxidation of MB. Furthermore, the reusability studies showed that the photocatalysts are globally stable for the photodegradation of MB.

Facile modification of TiO2 as S-Scheme multifunctional materials for environmental protection and energy-storage applications

This paper reports a simple one-step modification of commercial TiO2 with a conducting polytrimethoxyslilypropyl aniline (PTMSPA, a polyaniline derivative having silyl networks) to have multi-functional (photocatalytic, optical, pseudocapacitive, hydrophobic, porous, antibacterial, and electromagnetic interference shielding (EMI)) properties and demonstrates associated applications. We present the S-Scheme heterojunction (SHJ) formation between TiO2 and PTMSPA through band position alignments and designate the resultant TiO2 - TiO2- based SHJ multifunctional materials as MF-TSSM. The internal electric field that is generated at the interface facilitates the transportation of the photogenerated electron transfer . The XRD pattern of MF-TSSM exhibits mainly the peaks of anatase TiO2. The TEM image of MF-TSSM indicates that the TiO2 particles are spherical in shape with sizes showing variations in diameters ranging from 60 nm to 250 nm depending on the experimental conditions of preparation and TiO2 particles are homogeneously distributed within the PTMSPA matrix. The optical energy band gap of MF-TSSM is 1.60 eV, a much lower value than PTMSPA (3.02 eV), suggesting that the composite formation between TiO2 and PTMSPA. The contact angle of MF-TSSM is significantly increased to 47.1 ° from 8.0 of TiO2, informing the increase of hydrophobic characteristics. The rate constant (k) for methylene blue photodegradation was 0.030 min-1, and 0.010 min-1 for MF-TSSM and pristine TiO2, respectively, The MF-TSSM composite exhibits a higher specific capacitance value (28.7 F/g) than TMSPA (21.1 F/g). At a frequency of 0.42 THz, MF-TSSM and PTMSPA exhibit return loss features indicating good EMI shielding performance. The MF-TSSM has been tested against two different Gram-positive and Gram-negative bacterial strains. The nanoparticles were evaluated at doses of 10, 20, 40, and 80 µg/ml. The results indicated that Klebsiella pneumoniae demonstrated a greater zone of inhibition, ranging from 9 mm at 10 µg/ml to 23 mm at 80 µg/ml, indicating increased susceptibility. Pseudomonas aeruginosa exhibited reduced inhibition zones, ranging from 10 mm at 10 µg/ml to 14 mm at 80 µg/ml, indicating increased resistance. The excellent effectiveness of MF-TSSM against various Gram-positive and Gram-negative pathogenic bacteria is explained by the interaction between reactive oxygen species and the cellular components of the bacteria as well the electrostatic interaction arising between positive charges in TMSPA and negative charges in the cell components, resulting in notable cytotoxicity and damage to the bacterial cells. The research underscores the capability of these modified TiO₂ nanoparticles in addressing bacterial infections, with efficiency differing by bacterial strain.

Synthesis, characterization, electrochemical impedance spectroscopy performance and photodegradation of methylene blue: Mesoporous PEG/TiO2 by sol-gel electrospinning

Sol-gel and electrospinning methods successfully prepared porous TiO2 fibers. The samples were calcined at temperatures of 450 °C and 550 °C and characterized using different techniques. XRD analysis also revealed crystalline anatase and rutile phases of mp-TiO2 observed at calcining temperatures of 450 °C and 550 °C, whereas as-prepared showed an amorphous-like structure. Relatively higher surface area and photocatalytic efficiency were increased with a decrease in crystallite size. All samples absorb UV region. The Rs value of TiO2 calcined at 550 °C was 16.6 Ω, which is much lower than those of the 450 °C calcined TiO2 powder electrode (52.7 Ω) and as-prepared TiO2 electrode (95.3 Ω). In addition, the Rp resistance of TiO2 calcined at 550 °C electrode (5.85 kΩ) was also lower than those of 450 °C calcined TiO2 powder (39.0 kΩ) and as-prepared TiO2 electrode (68.9 kΩ), revealing better electronic and ionic conduction of TiO2 calcined at 550 °C electrode.

Investigating and correlating the photocatalytic activity of synthesised strontium titanate nanopowder with calcination temperature

In this study, SrTiO3 nanoparticles were synthesised in high yield using a simple and low-cost method, followed by calcination. The effect of the calcination temperature in the range from 700 to 1100 °C on the morphology, phase structure, crystallite size, and photocatalytic activity of SrTiO3 nanoparticles was investigated. Analysis of the morphology and structure of the synthesised samples revealed an increase in the average particle size from 70.4 to 361.72 nm as well as crystallite growth with increasing calcination temperature (from 800 to 1100 °C), likely due to the fusion of smaller crystallites into larger ones. A possible pathway for the growth mechanism of strontium titanate grains was also proposed. The SrTiO3 sample calcined at 800 °C exhibited the highest methylene blue (MB) photodegradation efficiency, achieving 100 % degradation within 30 min of irradiation. The pseudo-first-order reaction rate constant k for this sample was determined to be 0.156 min−1, which is almost 1.8 and 14.19 times higher compared to those of commercial P25 and SrTiO3, respectively. The analysis indicated that the high photoactivity of this sample was due to its high crystallinity, relatively small particle size, and optimal light absorption, which enhanced the separation and transport of the photogenerated charges and increased the number of active sites, thereby positively affecting the photocatalytic properties. Additionally, the effects of the initial dye concentration and amount of photocatalyst loaded on the photodegradation efficiency were investigated.

Synergistic photocatalytic activity of Bi2O3/g-C3N4/ZnO ternary heterojunction with dual Z-scheme charge transfer towards textile dye degradation

It is clear that a wide range of organic substances, including synthetic textile dyes, have the potential to negatively impact the environment. It is crucial to rationally develop highly effective photocatalysts for the degradation of such type of pollutants. In this regard, a heterostructured photocatalyst comes with enhanced charge separation and extended light absorption ability that improves photocatalytic performance. Therefore, In this study, a Bi2O3/g-C3N4/ZnO (BCNZ) ternary heterojunction photocatalyst was synthesized for the degradation of methylene blue (MB) textile dye.. Thermal polycondensation method was opted to synthesize g-C3N4, while ZnO and Bi2O3 photocatalysts were fabricated using co-precipitation method. Similarly, ternary heterojunction of BCNZ was constructed through co-precipitation method. The ternary heterojunction photocatalyst demonstrated better photodegradation ability due to dual Z-scheme charge transfer route. The dual Z-scheme heterojunction enabled the ternary heterojunction to exhibit enhanced light absorption capabilities with reduced recombination rates as well as enhanced charge separation and migration efficiency (confirmed via transient photocurrent response) that resulted in improved photocatalytic performance. The BCNZ dual Z-scheme photocatalyst displayed 92 % of degradation efficiency which was much higher than that of other (binary and pristine) photocatalysts. Scavenging tests and electron spin resonance spectroscopy revealed the significant role of the •O2−, and •OH radicals in the photodegradation of MB. Furthermore, the reusability test presented good stability and recyclability of the ternary photocatalyst with 80 % degradation efficiency after five catalytic cycles.

Enhancement of the photodegradation performance towards methylene blue and rhodamine B using AgxSn1–xO2 nanocomposites

In the present study, the structural properties, as well as the photodegradation performance of methylene blue (MB) and rhodamine B (Rh B) using hydrothermal synthesized AgxSn1–xO2 (0 ≤ x ≤ 1) nanocomposites were studied. The study was investigated using various techniques including EDS, XRD, FE-SEM, HR-TEM, photoluminescence spectroscopy, N2 adsorption-desorption, GC-MS, and a double-beam spectrophotometer. The tetragonal SnO2 phase dominates, while the cubic Ag2O phase appears at larger x ratios (x ≥ 0.5). The crystallite and particle sizes were slightly raised for a low Ag ratio but dramatically increased for higher x ratios. Different morphologies emerge depending on the composition, such as spherical and irregular particles for x = 0 and 1, sheet-like morphology for x = 0.05, 0.2, and 0.4, and worm-like morphology for x = 0.5. The maximum surface area was calculated using the BET method to be 358 and 354 m2/g for x = 0.2 and 0.4, respectively. The direct optical band gap depends on the x ratio and the crystallite size and equals 3.95eV and 3.70eV for x = 0 and x = 1, respectively. The synthesized AgxSn1–xO2 composites demonstrated excellent photodegradation efficiency (η) towards MB and Rh B. The majority of compositions had high η towards MB and the highest value of 99.6% was attained using Ag0.4Sn0.6O2 under the UV-visible irradiation for 1.5h. Also, synthetic composites demonstrated efficient photodegradation of Rh B, particularly for higher Ag content (η = 94.4% at x = 0.5). The catalysts revealed acceptable reusability and stability, and the degraded products were studied using the GC-MS technique with a proposed mechanism of degradation. The improvement in photodegradation of MB and Rh B dyes can be attributed to an increase in surface area, as well as the development of shape and optical characteristics.

2D porous hexaniobate-bismuth vanadate hybrid photocatalyst for photodegradation of aquatic refractory pollutants

Metal oxide semiconductors are highly promising due to their excellent photocatalytic performance in the photodegradation of industrial waste containing refractory chemical compounds. A hybrid structure with other semiconductors provides improved photocatalytic performance. In this work, porous and two-dimensional (2D) hexaniobate-bismuth vanadate (Nb6-BiVO4) Z-scheme hybrid photocatalysts are synthesized by chemical solution growth (CSG) of BiVO4 over electrophoretically deposited Nb6 thin films. The structural and morphological analysis of Nb6-BiVO4 hybrid thin films evidenced the well-crystalline uniform growth of monoclinic scheelite BiVO4 over lamellar Nb6 nanosheets. The Nb6-BiVO4 hybrid thin films exhibit a highly porous randomly aggregated nanosheet network, creating the house-of-cards type morphology. The Nb6-BiVO4 hybrid thin films display a strong visible light absorption with band gap energy of 2.29 eV and highly quenched photoluminescence signal, indicating their visible light harvesting nature and intimate electronic coupling between hybridized species beneficial for photocatalytic applications. The visible-light-driven photodegradation performance of methylene blue (MB), rhodamine-B (Rh-B) dyes, and tetracycline hydrochloride (TC) antibiotic over Nb6-BiVO4 hybrid are studied. The best optimized Nb6-BiVO4 thin film shows superior photocatalytic activity for photodegradation of MB, Rh-B dyes, and TC antibiotic with photodegradation rates of 87.3, 92.8, and 64.7 %, respectively, exceptionally higher than that of pristine BiVO4. Furthermore, the mineralization study of Nb6-BiVO4 thin film is conducted using chemical oxygen demand (COD) analysis. The optimized Nb6-BiVO4 thin film shows superior percentage COD removal of 83.33, 85.42, and 61.36 % for MB, Rh-B dyes and TC antibiotic, respectively. The present results highlight the expediency of hybridization in enhancing the photocatalytic activity of pristine BiVO4 by minimizing its charge recombination rate and improving chemical stability.

Green synthesis of undoped and yttrium, bismuth co-doped titanium dioxide nanoparticles using Bryophyllum pinnatum for photocatalytic application

In this research, a non-toxic, inexpensive, and environment-friendly green synthesis route was investigated to synthesize undoped and Y, Bi co-doped TiO2 nanoparticles by using Bryophyllum pinnatum leaf extract. Precursor material titanium isopropoxide (TTIP) was utilized for both undoped and co-doped TiO2 and Yttrium and Bismuth were added to 1, 2, and 3 percent as co-dopants. The obtained undoped and Y, Bi co-doped TiO2 nanoparticles were characterized by various analytical techniques, which include X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), and UV–Visible spectroscopy for the evaluation of the structural, morphological, and photocatalytic activity. Anatase phase formation was observed from the XRD analysis for both undoped and Y, Bi co-doped TiO2 nanoparticles. The average particle size for undoped TiO2 nanoparticles was found to be 15.92 nm which raised to 21.70 nm for 3 % co-doping. UV–Vis Spectroscopy analysis revealed a reduction on band gap energy (Eg) for Y, Bi co-doped TiO2 nanoparticles. Methylene blue (MB) photodegradation demonstrates co-doping with Y, Bi significantly increases the photocatalytic activity. Overall, green synthesis using Bryophyllum pinnatum was found to be an economical method to fabricate TiO2 NPs that shows great improvement in photo-degradation characteristics.

Ca-doped g-C3N4 was prepared by two-step calcination for efficient photodegradation of methylene blue

Ca-doped g-C3N4 was prepared by two-step calcination for efficient photodegradation of methylene blue

A Novel Approach to Waste Recycling and Dye Removal: Lithium-Functionalized Nanoparticle Zeolites.

A zeolitic sample, named MT-ZLSH, was synthesized using mining tailings (MT) as the precursor material, resulting in a structure comprising: Linde type A (LTA) and sodalite-hydroxysodalite (ZLSH). This naming convention reflects the material's origin and its structural characteristics. The material was further modified by incorporating lithium, producing MT-ZLSH-Li+. Physicochemical characterizations were performed, and the material was evaluated for its potential to remove methylene blue (MB) from synthetic wastewater through adsorption and photocatalysis. Efficient adsorption was observed under typical wastewater pH conditions, with a maximum adsorption capacity of 23.4 mg·g-1, which fit well with the Langmuir isotherm model. The key mechanisms governing MB adsorption were identified as ion exchange, electrostatic attraction, and hydrogen bonding. The adsorption process was exothermic, with kinetic data fitting both the pseudo-second order and intraparticle diffusion models, achieving 82% removal and a maximum adsorption capacity of 40 mg·g-1 over 12 h. MB adsorption followed a two-step process, initially involving film diffusion, followed by intraparticle diffusion. Additionally, photocatalytic degradation of MB achieved 77% degradation within 180 min. However, a decrease in reusability was observed during a second cycle of MB adsorption and photodegradation, highlighting the need for further optimization to enhance the material's long-term performance.

Preparation and Photodegradation of TiO2 Thin Films on the Inner Wall of Quartz Tubes.

Titanium dioxide thin films on the inner wall of quartz tubes were prepared in situ by the sol-gel method. Meanwhile, copper and cerium were loaded onto the surface of the titanium dioxide thin films to enhance photocatalytic activity and broaden the range of light absorption. X-ray diffractometer, X-ray photoelectron spectroscopy, scanning electron microscopy, energy dispersive X-ray spectrum, N2 gas adsorption, UV diffuse reflectance spectroscopy, electron paramagnetic resonance, photoluminescene spectroscopy, and so on were used to characterize the structure, morphology, chemical composition, and optical properties of the prepared photocatalyst. Methylene blue (MB) was used as a simulated organic pollutant to study the photocatalytic performance of the photocatalyst, which was a translucent, structurally stable, and reusable high-efficiency photocatalytic catalyst. Under UV lamp irradiation, the MB photodegradation efficiency was 94.5%, which reached 91.2% after multiple cycles.

Optimization of methylene blue photodegradation by Cr-PTC[sbnd]HIna/TiO2 composite using box-behnken design application

The Cr-PTCHIna/TiO2 composite synthesized using an isonicotinic acid modulated chromium and perylene-based metal-organic framework (Cr-PTCHIna MOF) and titanium oxide (TiO2) showed promising results for the photodegradation of methylene blue. The composite was synthesized through the solvothermal method with a molar ratio of Cr and Ti of 1:1 mmol. The XRD diffraction patterns of Cr-PTCHIna/TiO2 composite showed sharp peaks at 2θ = 12°, 25°, 27°, 37°, 48°, 54°, 55°, and 62° with crystal sizes of 14.144 nm. The Cr-PTCHIna/TiO2 composite has a band gap energy of 2.02 eV and a rod-shaped morphology with a particle size of 239.16 nm. The Box-Behnken Design (BBD) demonstrated that the composite can achieve an optimum degradation efficiency of methylene blue of 88.55 % under methylene blue initial concentration of 35.7 ppm, pH 6.6, and photocatalyst mass of 0.13 % under 250-watt Mercury lamp irradiation for 2 h.

Hydrothermal growth of Zn2GeO4 nanorods for optical and (Photo)Catalytic applications: An experimental and theoretical study

From the material design perspective, we reported a systematic investigation based on theoretical and experimental approaches to explore the physical properties of Zn2GeO4 nanorods prepared by hydrothermal method with different zinc precursors for optical and (photo)catalytic applications. All ZGO samples exhibited uniform nanorod morphology with high purity and crystallinity. A negative zeta potential ranging from −13 mV to −16 mV have been observed for these nanorods. Bandgap values indicated variations among samples synthesized with different precursors. The photoluminescence and photocatalytic activities for these nanorods, have been attributed to the presence of oxygen vacancies on the Zn2GeO4 surfaces. Experimental evidence suggests that these surface defects favor the formation of hydroxyl radicals identified as primary reactive oxygen species responsible for the methylene blue photodegradation. Toxicity testing of photocatalytic residues showed minimal phytotoxic effect on lettuce seed (Lactuca sativa) germination. Additionally, Zn2GeO4 was utilized as an acid catalyst for synthesizing isoxazol-5(4H)-ones, resulting in an increase in the yield from 69 % to 92 % by using this catalyst in multicomponent reactions. Lastly, the theoretical efforts outlined in the study aim to enhance the comprehension of the material design with well-defined morphology using realist theoretical models for the Zn2GeO4 nanorods for the first time.

Enhanced photocatalytic performance of ternary g-C3N4/UiO-66/Ag3VO4 composite for methylene blue degradation under visible light irradiation

Anovel Ag3VO4/UiO-66/g-C3N4-based photocatalystwassynthesized using the solvothermal approach and characterized using XRD, SEM, FTIR, PL, and UV–Vis DRS. The photodegradation capacityof each componentwas tested using aqueous solutions of methylene blue (MB) and real sample solutions. It was found that the ternary composites (g-C3N4/UiO-66/Ag3VO4, 1 wt%, 5 wt%, 10 wt%, and 15 wt% g-C3N4) demonstrated higher degradation efficiency than the single and binary constituentsowing to beneficial interactions in the composite, which favor successful interfacial charge transfer and improve photogeneratede--h+pair separations. The influence of various experimental factors such as pH, initial dye amount, photocatalyst dose, and scavengers on MB degradation was examined. At optimal conditions of pH 6, catalyst load of 60 mg, and initialdye content of 10 ppm, the percent photodegradation of MB under irradiation with visible light (indoorsystem) was 99.35 %, while in the outdoor system,it was 99.5 % in 240 min. The selected photocatalyst was also applied for the degradation of real sewage sample solution, which was found to be 80.2 % under indoor and 89 % under outdoor experimental undertakings. After five cycles, the potential of the photocatalystremained substantial, indicating remarkable reusability. The scavenging experiment suggested that the principal active species were found to be superoxide (O2•) and hydroxide radicals (•OH). Thus, the composite g-C3N4/UiO-66/Ag3VO4 could be a promising option for industrial effluent removalapplications, particularly in the purification of organic dye-containing wastewater.

Synergistic adsorption-photocatalytic remediation of methylene blue dye from textile industry wastewater over NiFe LDH supported on tyre-ash derived activated carbon

The photocatalytic performance of the multilayered NiFe LDH/Activated Carbon was evaluated for the degradation of methylene blue (MB) in industrial textile wastewater, considering prior adsorption on the photocatalyst surface. The XRD, XPS, BET, TEM and FE-SEM results confirmed that the highly exposed mesoporous layers, carbon backbone, and interlayer anions serve as active sites responsible for the adsorption of MB dye due to the expected electrostatic interactions. Electrochemical methods such as CV, LSV and EIS revealed the improved conductivity and supported the interactions observed. Encouraged by these interactions, the irradiation of visible light enabled the degradation of methylene blue, and the degradation products were monitored using UPLC chromatograms and MS spectra. The removal efficiencies of the MB dye were found to be 17.5 %, 51.2 %, 67.1 %, 84.8 %, and 94.2 % due to photolysis, adsorption, and degradation on AC, NiFe LDH nanosheets, and NiFe LDH/AC nanocomposite, respectively. The results of the UPLC chromatograms and MS spectra suggested that MB was mineralized into simpler fragments after 30 min of visible light irradiation. Scavenging studies were examined using a series of scavenging agents. However, the maximum photodegradation was attained in the absence of the scavengers. The reusability studies showed that the MB photodegradation efficiency declined by 20.8 %, possibly due to the loss of the catalyst during the washing step. Nonetheless, the NiFe LDH/AC structure remained intact, suggesting the strong stability of the photocatalyst. The plausible degradation mechanism and probable degradation pathway of MB were outlined and supported by the chromatographs and MS results. The overall results suggest that photocatalysis of cationic dyes such as MB on NiFe LDH/AC should be encouraged to work towards sustainable solutions for textile water treatment.

Enhanced efficiency of MoS2/SnO2 nanocomposite as a catalyst for the photodegradation of methylene blue

Enhanced efficiency of MoS2/SnO2 nanocomposite as a catalyst for the photodegradation of methylene blue

Bijel-based mesophotoreactor with integrated carbon nitride for continuous-flow photocatalysis

The integration of continuous-flow technologies with heterogeneous photocatalysis has recently emerged as a promising strategy for the development of sustainable processes. Although conventional packed bed reactors have been extensively utilized in industrial catalytic applications, they face challenges related to energy transfer in the photocatalytic systems. This study presents an innovative approach to address this issue by integrating heterogeneous photocatalysts with an organic polymer, leading to the fabrication of a mesophotoreactor featuring a bijel-based structural configuration. This novel strategy involves hybridizing polypentadecalactone and in situ confining of carbon nitride in a bicontinuous porous mesoarchitecture. The structural and physicochemical properties of the resulting catalytic composite material are evaluated through an array of characterization methods, affirming the successful integration of carbon nitride within the overall structure. The unique bicontinuous porous architecture of the composite and its suitability for industrial applications is verified, as exemplified by its exceptional efficiency in the photodegradation of methylene blue (>99 %) under flow conditions and remarkable stability up to three reaction cycles. A mathematical model is developed to describe continuous photocatalytic processes occurring in the novel tubular mesophotoreactor, with a specific focus on the degradation of the methylene blue dye. This model is successfully validated, leading to results in agreement with the experimental measurements. Additionally, fluid dynamics simulations demonstrate that the mesophotoreactor design allows for the effective diffusion of light through its channels, resulting in higher irradiation levels compared to conventional systems such as packed bed reactors. The innovative design of the catalytic reactor presented in this work offers a versatile and efficient alternative to the conventional heterogeneous systems, significantly broadening the range of applications for photocatalytic processes.