Photocatalytic Degradation Of MB Research Articles

Copper Doping of CdS Nanoflakes and Nanoflowers for Efficient Photocatalytic Degradation of MB and MV Dyes

Copper Doping of CdS Nanoflakes and Nanoflowers for Efficient Photocatalytic Degradation of MB and MV Dyes

Decoration of 2 H-MoS2 on the surfaces of activated carbon derived from bamboo stem biomass waste: A regenerative novel architecture for effective degradation of methylene blue under natural light

The development of visible light-assisted photocatalyst materials is considered a sustainable technology for textile dye pollutant degradation. In this work, a bamboo stem-derived activated carbon/Molybdenum disulfide (AC/MoS2) composite was synthesized using the wet impregnation method. The synthesized AC/MoS2 (5%) (ACM composite) shows enhanced photocatalytic degradation efficiency (98%) for MB degradation within 90 min compared with AC (94%) and MoS2 (33%) under natural light irradiation. FESEM analysis shows the uniform deposition of 2 H-MoS2 on the surface of AC. HRTEM analysis revealed that ACM composite consists of ultra-small activated carbon nanoparticles with a diameter of ∼20 nm and a layered MoS2 with a lateral thickness of ∼150 nm. The effect of catalyst load, pH effect, and MB concentration were evaluated to optimize the photocatalytic activities of AC and ACM composites. The results reveal that the ACM composite possesses high photocatalytic activity with a catalyst quantity of 10 mg at pH 8. Scavenger trapping analysis confirms that hydroxyl radical (•OH) and photogenerated holes (h+) are the main reactive species for photocatalytic degradation of MB. After three cycle experiments, the ACM composite exhibited a slight decrease in the photocatalytic efficiency (89%) and also possesses high stability, which can be regenerated for sustainable photocatalytic material. Moreover, the ACM composite exhibits a long visible absorption range and high structural stability, enhancing the charge separation efficiency of photogenerated electron-hole pairs. This proposed method offers a cost-effective and biomass-derived photocatalyst for the textile wastewater treatment process.

Reduced electron/hole recombination in Z-scheme nanostructure of zeolitic imidazolate framework-11/graphitic carbon nitride as photocatalyst under visible light

In this research, for the first time, the synthesis of nanostructure of zeolitic imidazolate framework-11/graphitic carbon nitride (ZIF-11/g-C3N4 X) with different weight of g-C3N4 (X: 0.01, 0.1, 0.3 g) is reported. Their performance was compared in photocatalytic degradation of MB under visible light. Synthetic samples were characterized by X-Ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), X-ray photoelectron spectrometer (XPS), diffused reflectance spectroscopy (DRS), Field emission scanning electron microscopy (FE-SEM), Transmission electron microscope (TEM), Brunauer–Emmett–Teller (BET), Electrochemical Impedance Spectroscopy (EIS) and Photoluminescence (PL) analysis. Based on the results, Z-scheme ZIF-11/g-C3N4 0.3 was selected as the best sample. FESEM and TEM images indicated that g-C3N4 sheets were complicated on the surface of ZIF-11 with rhombic dodecahedron (RHO) morphology. The surface area and band gap of ZIF-11/g-C3N4 0.3 was determined as 174.5 m2/g and 2.58 eV, respectively. The recombination of charge carriers in the ZIF-11/g-C3N4 0.3 nanostructure was reduced. Photocatalytic degradation efficiency of MB (5 ppm), pH = 7, visible irradiation (120 W-60 min) using 0.1 g of ZIF-11/g-C3N4 0.3 was achieved 72.7% with first-order kinetic model and acceptable stability in three consecutive cycles. Further, the total organic carbon (TOC) removal rate by ZIF-11/g-C3N4 0.3 after 5 h were 66.5%.

Synthesis of hierarchical FePc-ZS-1 zeolites and its rapid photocatalytic degradation of MB under visible light and H2O2

This manuscript details the successful production of hierarchical FePc-ZS-1 zeolite with rapid visible photocatalytic properties through an impregnation method utilizing reactive dyes as a sensitizing agent. The impact of the dye species on the visible photocatalytic properties of the resulting products was thoroughly examined in a Fenton reaction system created by combining H2O2 and the synthesized materials. The synthesized materials were subjected to characterization through various methods including XPS, XRD, FTIR, SEM, and N2 adsorption-desorption isotherm.The synthetized FePc-ZS-1 zeolite is an ellipsoid with smooth surface, highly ordered pore structure, and characteristic peaks in the visible region of 400–800 nm. The final results indicate that the phthalocyanine dye-sensitized zeolite had the most significant impact on the visible light degradation efficiency of methylene blue dye solution. The degradation efficiency of FePc-ZS-1 zeolite on MB solution reached an amazing 99.96 % in just 30 min. After examining the photocatalytic activity and kinetics model, it was determined that the photocatalytic activity is consistent with the apparent first-order kinetic model. Furthermore, through radical capture experiments and ESR characterization, the hypothesized mechanism of the photocatalytic reaction and the MB degradation pathways were thoroughly addressed. Finally, the samples were subjected to reuse experiments, and the results showed that the degradation rate was still above 90 % after 5 times of reuse, with good recyclability. The above results indicate that the visible photocatalytic material prepared in this study is a promising source of green energy, which is worthy of further application.

Photocatalytic Degradation of Methylene Blue from Aqueous Solutions by Using Nano-ZnO/Kaolin-Clay-Based Nanocomposite

Dyes are toxic organic compounds released as effluent from various industries that need proper treatment as they pose serious hazards to the environment and living beings, including humans. Nanocomposites can be employed as photocatalysts for the elimination of such organic compounds from wastewater. One such attempt is made in this present research study, where a zinc-based nanocomposite has been fabricated for the elimination of the methylene blue dye (MB). For the development of nanocomposite, zinc oxide nanoparticles (ZnONPs) were prepared to utilize Allium sativa peel (garlic skin) extract, which was further processed to develop ZnO/kaolin clay NC. ZnONPs and ZnO/kaolin clay NC formation have been confirmed by UV–Vis spectral bands at 379 nm and 423 nm. The NC was rod-shaped, with width of 60–100 nm and length of 200–800 nm and an average size of 50.0 ± 0.58 nm. Both materials were compared for their efficacy in photocatalytic degradation of the MB under solar light irradiation. ZnONPs removed 65% of MB, whereas the degradation efficiency of ZnO/clay NC was calculated to be 96% for 10 ppm MB. A kinetics study for photocatalytic degradation of MB using both nanomaterials showed that the photocatalytic degradation followed the pseudo-first-order (PFO) type of reaction. This investigation represents an expeditious, lucrative, ecological, and appropriate technique for the fabrication of functional nanomaterials for the remediation of diverse organic pollutants.

Sustainable and solar light assisted photocatalytic degradation of MB and MG dyes by Co3O4/g-C3N4 nanocomposite

Sustainable and solar light assisted photocatalytic degradation of MB and MG dyes by Co3O4/g-C3N4 nanocomposite

One-pot synthesis of In2O3/ZnO nanocomposite photocatalysts and their enhanced photocatalytic activity against cationic and anionic dye pollutants

An In2O3/ZnO nanocomposite was synthesized by co-precipitation and applied in the photocatalytic degradation of cationic and anionic dyes. The nanocomposite was characterized by X-ray diffractometry (XRD), Raman spectroscopy, X-ray photoelectron spectrometry (XPS), scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HRTEM), energy dispersive X-ray spectrometry (EDS), surface area analysis and UV–visible diffuse reflectance spectrometry (UV–Vis DRS). The XRD, Raman and XPS analyses revealed that the nanocomposite was composed of two phases (In2O3 and ZnO). SEM images showed agglomerations of In2O3 and ZnO, and TEM images confirmed the adhesion of In2O3 nanoparticles to the surface of ZnO. The specific surface area of the nanocomposite increased from 5.86 to 8.41 m2/g with increments of In2O3 content. The optical bandgap energies of ZnO and In2O3 powders were 3.12 and 2.90 eV, respectively. The best photocatalyst was 2%In2O3/ZnO nanocomposite and the optimal dosage was 150 mg. Under UV irradiation, 92.17, 55.54 and 38.61% of MB, RhB and MO, respectively, were degraded over the 2%In2O3/ZnO nanocomposite. Since the point of zero charge of 2%In2O3/ZnO was about 6.6, MB and RhB were more completely degraded under basic conditions while MO was more completely degraded under acidic conditions. The possible charge transfer mechanism for photocatalytic degradation over the 2%In2O3/ZnO nanocomposite was proposed based on an active species test. The results showed that h+, •OH and •O2- species were the reactive species responsible for the photocatalytic degradation of MB, RhB and MO. The In2O3/ZnO nanocomposite could remove the cationic dyes from water in a neutral condition and exhibited good stability.

Low-Temperature In Situ Reaction Synthesis of Quasi Core–Shell ZnO/rGO Composites for the Efficient Photocatalytic Degradation of MB

Low-Temperature In Situ Reaction Synthesis of Quasi Core–Shell ZnO/rGO Composites for the Efficient Photocatalytic Degradation of MB

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.

ZnO nanocomposites supported by acid-activated kaolinite as photocatalysts for the enhanced photodegradation of an organic dye

Nanocomposite photocatalysts have attracted considerable attention for their enhanced photocatalytic ability compared to single metal oxide photocatalysts. The matrix in a nanocomposite plays a vital role in determining the efficiency of a photocatalyst. Acid-activated kaolinite (AAK) provides an excellent matrix owing to its higher surface area. In the present study, two nanocomposites were prepared with varying compositions of ZnO and acid-activated kaolinite (AAK) for use as photocatalysts. The ZnO/AAK nanocomposites were prepared in a wet chemical precipitation method and characterized using a range of techniques. The photocatalysts were then used for the photocatalytic degradation of MB in an aqueous solution under UV irradiation. The reaction parameters affecting the photocatalytic efficiency, such as the pH of the solution, initial concentration of dye, and catalyst dose, were optimized. The recyclability of the nanocomposites was also evaluated. ZnO was synthesized and dispersed over the AAK matrix. The particle size of ZnO in nanocomposites was ∼50 nm, and the optical bandgap of the nanocomposites was reduced significantly compared to single ZnO. Both AAK/ZnO nanocomposites exhibited high degradation efficiency. In particular, the ZK-30 nanocomposite, containing only 30 wt% ZnO, removed 98 % of MB from an aqueous solution. The recyclability test of the nanocomposites exhibited 80–99 % dye removal for up to three consecutive photocatalytic cycles.

Microtubular Nanoporous g-C3N4@Ag as an Efficient Photocarrier Transfer Agent and Visible Light-Harvesting for Photodegradation of Methylene Blue

Microtubular nanoporous graphitic carbon nitride@silver (MN-g-C3N4@Ag) was synthesized in order to investigate the efficiency of a photocarrier transfer agent and visible light-harvesting to improve the applicability of photocatalytic reactions in solving the environmental pollution problem. The content of AgNPs was optimized, and MN-g-C3N4 with 5% of Ag shows the best performance. The results indicated that Ag nanoparticles were homogeneously distributed onto the MN-g-C3N4 surface, which leads to the absorption and harvesting of more visible light on the catalyst. The statistical analysis of the experimental data showed that the kinetic model and the adsorption isotherms for the surface adsorption process are consistent with the Langmuir isotherm [Qmax = 272.0 (mg g–1)] and the pseudo-second-order kinetics [Qe.cal = 280.0 (mg g–1)]. Also, the kinetic rate constant of photocatalytic degradation for the MN-g-C3N4@Ag photocatalyst is 7.5 times higher than that of MN-g-C3N4 and 59.0 times higher than that of bulk g-C3N4. Also, the mechanism of photocatalytic degradation showed that holes and •O2– are the main species for photocatalytic degradation of MB through surface adsorption. As a result, the MN-g-C3N4@Ag nanocomposite can use silver metal as both a Schottky barrier and plasmonic effects generator and MN-g-C3N4 itself as a porous photocatalyst with unique charge transfers in the axial direction. Which can synergistically be prolonged lifetime and photocarrier diffusion length, proving that MN-g-C3N4@Ag can efficiently be operated in environmental pollutant remediation.

Unlocking the Potential of N-Doped SnO2 for Sustainable Photocatalytic Degradation of Carcinogenic Dyes

Environmental adulteration is an emerging concern due to the discharge of wastewater effluents from several sources. Several carcinogenic dyes are the major contaminants in these water bodies. These could cause long-lasting and detrimental effects to humans as well as aquatic ecosystems. For efficient degradation of such dyes, the exploration of nanotechnology has demonstrated huge potential. Herein, the degradation of dyes (MB, CV, and MO) has been carried out photocatalytically using N-doped SnO2 nanoparticles (N:SnO2 NPs) as well as in presence of a sacrificial agent, EDTA. These NPs were synthesized at an ambient temperature. Different characterization techniques were used throughout the analysis of the synthesized NPs. The PXRD analysis reveals formation of single-phase rutile structure with tetragonal symmetry. Using the Scherrer formula, the size of the NPs was found to be less than 5 nm, exhibiting increases in size with N doping. Further, morphological analysis through field emission scanning electron microscopy (FESEM) and transmission electron microscopy (TEM) examined the existence of highly agglomerated, spherical NPs. The thermogravimetric analysis (TGA) results depict the thermal stability of the synthesized NPs up to a temperature of 800 °C. These synthesized N:SnO2 NPs exhibit potent efficiency for the photocatalytic degradation of MB, MO, and CV dyes with an efficiency of 93%, 83%, and 73% degradation, respectively, under UV light irradiation. Additionally, the effect of the sacrificial agent, EDTA, was observed on the degradation process and resulted in a degradation of ~90% MB dye, 88% CV dye, and 86% MO dye within 15 min of UV light irradiation.

Novel Laser-Assisted Chemical Bath Synthesis of Pure and Silver-Doped Zinc Oxide Nanoparticles with Improved Antimicrobial and Photocatalytic Properties

Antimicrobial resistance poses a significant threat to global health, amplified by factors such as water scarcity and suboptimal hygienic practices. Addressing AMR effectively necessitates a comprehensive strategy encompassing enhanced access to potable water, developing innovative antibiotics, and exploring alternative treatment modalities, such as harnessing solar photocatalysis with zinc oxide nanoparticles for water purification and antimicrobial applications. The Laser-Assisted Chemical Bath Synthesis (LACBS) technique facilitates the fabrication of pure ZnO nanostructures, providing a potentially efficacious solution for mitigating pathogen proliferation and managing wastewater. The photocatalytic degradation of MB and MO dyes was investigated using blue laser light at 445 nm, and degradation rates were determined accordingly. Ag-doped ZnO nanostructures were characterized through X-ray diffraction, field emission scanning electron microscopy, energy dispersive X-ray spectroscopy, and Fourier-transform infrared spectroscopy. The antimicrobial efficacy of LACBS-synthesized ZnO nanoparticles was assessed against C. albicans, S. aureus, B. subtilis, E. coli, and K. pneumoniae using the disc diffusion method, revealing 40 mm, 37 mm, 21 mm, 27 mm, and 45 mm inhibition zones at the highest concentration of doped-Ag (4.5%), respectively. These inhibition zones were measured in accordance with the guidelines established by the Clinical and Laboratory Standards Institute. X-ray diffraction patterns for ZnO, ZnOAg(1.5%), ZnO:Ag(3%), and ZnO:Ag(4.5%) samples revealed variations in intensity and crystallinity. Scanning electron microscopy exposed morphological disparities among the nanostructures, while energy-dispersive X-ray spectroscopy verified their elemental compositions. UV-Vis absorption analyses inspected the optical band gaps, and Fourier-transform infrared spectra identified the stretching mode of metal-oxygen bonds. Under blue laser irradiation, Ag-doped ZnO exhibited enhanced photocatalytic activity during the photocatalytic degradation. These nanoparticles, synthesized via the cost-effective and straightforward LACBS method, benefit from silver doping that augments their electron-trapping properties and photocatalytic activity, thereby enabling efficient dye degradation. Consequently, Ag-doped ZnO nanoparticles hold promise as a potent solution for counteracting drug-resistant microorganisms and as an effective disinfectant.

Plasmonic enhanced branched Ag sensitized Cu2O–CuO/TiO2 heterojunction with unprecedented photocatalytic degradation under visible light

A novel plasmonic Ag assisted Cu2O–CuO/TiO2 heterojunction photocatalyst was prepared using a facile sol-gel technique, and its MB degradation efficiency was explored. The physicochemical, morphostructural, and spectroscopic analyses using XRD, UV–vis-DRS, SEM, TEM, Raman, ESR, PL and XPS showed the formation of Ag@Cu2O–CuO/TiO2 hybrid photocatalyst, exhibiting surface plasmon resonance (SPR) and interfacial ternary heterojunctions. The SPR exhibited by the bulbous branched Ag nanostructures resulted in broad visible light absorption that extended into the near-infrared region. This plasmonic-heterojunction hybrid photocatalyst has shown excellent photocatalytic degradation, far surpassing the performance of its pristine counterparts under visible light illumination. The improved photocatalytic degradation of MB is attributable to the synergistic impact of reduced electron-hole pair recombination owing to Cu2O–CuO/TiO2 ternary junction, broad visible light absorption and near-field enhancement through the surface plasmon resonance effect. The current study demonstrates an integrated plasmonic-heterojunction photocatalytic system that offers a promising avenue for enhancing photocatalytic performance in dye-contaminated water treatment.

Real-Time UV/VIS Spectroscopy to Observe Photocatalytic Degradation

In this work, we have developed a real-time UV/VIS spectroscopy method using a broadband Xenon Arc lamp to detect photocatalytic reactions in real time. A CMOS camera was used instead of an output slit to capture all spectral information simultaneously, which can enable a real-time detection of the UV/VIS absorption of the analytes within a single frame of the camera. To verify real-time spectroscopy, a wavelength calibration process was performed using three laser line filters and a didymium glass filter sample. To demonstrate that this real-time spectroscopic setup can be used for rapid measurements, MB samples were used to observe the real-time photocatalytic degradation of MB by TiO2 nanoparticles. For real-time measurement, four samples with different TiO2 nanoparticle quantities showed different photocatalytic degradation mechanisms. By plotting the spectra every 20 ms, the series of spectra clearly showed the degradation of MB in real time.

Lauric acid surface modified Co2+-ZnO@SSM composite membrane: Photocatalytic degradation of MB and oil/water separation for removal of organic pollutants

The stainless steel wire mesh supported Co2+-doped ZnO with lauric acid modification (LA/Co2+-ZnO@SSM) was prepared through hydrothermal method for dual-functional oil/water separation performance and high photocatalytic activity. By changing the immersing time of LA, the surface polarity of the LA/Co2+-ZnO@SSM composite membrane could be efficiently adjusted from hydrophilic to hydrophobic. The superhydrophobicity of LA/Co2+-ZnO@SSM was achieved after LA immersing 120 min, and the WAC value reached as 156.6 ± 3.0°. In different oil/water mixture systems, the LA/Co2+-ZnO@SSM composite membrane exhibited excellent oil/water separation ability and separation throughput, and the separation efficiency still remained above 90 % after 10-cycle separation. Meanwhile, the LA/Co2+-ZnO@SSM composite also maintained an excellent photocatalytic activity, and the photocatalytic efficiency for methylene blue degradation reached 90 %. Even in the solution of complex organics and oil, the photocatalytic degradation efficiency was still above 75 %. In addition, LA/Co2+-ZnO@SSM composite membrane also showed a low adhesion, good flexibility and anti-pressure ability. All results indicated that the dual-functional LA/Co2+-ZnO@SSM composite membrane with visible light-driven photocatalysis and oil/water separation performance could be used for practical complex wastewater as a novel purification strategy.

Fabrication of High Surface Area TiO2-MoO3 Nanocomposite as a Photocatalyst for Organic Pollutants Removal from Water Bodies

A nanocomposite (NC) of titanium (IV) oxide (TiO2) and molybdenum (VI) oxide (MoO3) was synthesized using a hydrothermal route. Detailed analyses using transmission electron microscopy, X-ray diffraction, X-ray fluorescence (XRF), Brunauer–Emmett–Teller (BET) isotherms, X-ray photoelectron spectroscopy, Raman, and diffuse reflectance infrared Fourier transform spectroscopy were carried out and confirmed the successful formation of pure TiO2-MoO3 (Ti-Mo) NC. The Ti-Mo NC possesses sizes in the range of 150–500 nm. XPS, Raman, and DRIFT shift measurements confirmed the formation of mixed oxide linkage in the form of Ti-O-Mo. Sorption of nitrogen isotherms revealed a significant increase in the number and pore widths of mesopores in the NC. Water sorption isotherms revealed enhanced affinity of the nanocomposites for water relative to the pure metal oxides. The BET surface area for Ti-Mo NC from the nitrogen adsorption isotherm was 129.3 m2/g which is much higher than the pure metal oxides (i.e., 37.56 m2/g for TiO2 and 2.21 m2/g for MoO3). The Ti-Mo NC provided suitable adsorption sites that captured the studied carbamates from the solution and promoted their photodegradation process. The photocatalytic degradation of MB in the presence of the catalyst was enhanced by 2.9 and 5.5 folds upon irradiation with white LED and 302 nm UV light sources, respectively.

Photocatalytic Degradation of Methyl Orange and Methylene Blue Dyes by Engineering the Surface Nano-Textures of TiO2 Thin Films Deposited at Different Temperatures via MOCVD.

TiO2 thin films were deposited on quartz substrates by metal-organic chemical vapor deposition (MOCVD) at temperatures of 250, 350, and 450 °C. X-ray diffraction (XRD) data revealed the production of a pure anatase phase, a decrease in crystallite size, and a textural change as deposition temperature increased. Atomic force microscopy (AFM) was used to study the morphological properties and confirm XRD results. UV-Vis.-NIR spectroscopy was used to investigate the optical properties of the samples. The effect of deposition temperature on wettability was investigated using contact angle measurements. Sunlight photocatalytic properties increased with the increase in deposition temperature for methyl orange and methylene blue. Films were post-annealed at 500 °C for 2 h. The effect of annealing on all the above-mentioned properties was explored. The kinetic analysis demonstrated superb agreement with the kinetic pseudo-first-order model. The rate of photocatalytic degradation of MB was ~8, 13, and 12 times that of MO using 250, 350, and 450 °C deposited films, respectively. Photodegradation was found to depend on the specific surface area, type of pollutant, and annealing temperature.

Unlocking the potential of thermally exfoliated ultrathin g-C3N4 nanosheets: abundant active sites for enhanced solar photocatalysis

Thermally exfoliated g-C3N4 with a large surface area and abundant active sites for improved photocatalytic degradation of MB, RhB, and CIP in diverse aqueous media.

Fabrication of a hybrid phase TiO2/g-C3N4 heterojunction composite with enhanced adsorption and photocatalytic degradation of MB under visible light

Excellent MB adsorption and degradation capacity of hybrid phase TiO2/g-C3N4 photocatalysts based on surface polarization and S-scheme charge transfer.