Photocatalytic Degradation Of Methylene Blue Research Articles

Engineered g-C3N4/MnO2 Nanocomposite for Exceptional Photocatalytic Methylene Blue Degradation and Robust Antibacterial Impact

Engineered g-C3N4/MnO2 Nanocomposite for Exceptional Photocatalytic Methylene Blue Degradation and Robust Antibacterial Impact

Magnetic zinc oxide/silica microbeads for the photocatalytic degradation of azo dyes

Photocatalysis is a promising technique for the complete degradation of azo dyes that are present in wastewater. In this work, a new photocatalyst in the form of ZnO/Fe3O4/SiO2 hybrid microbeads was fabricated for the photocatalytic degradation of methylene blue. The microbeads were synthesised through self-assembly and subsequent agglomeration of nanoparticles within an aqueous phase of a water-in-oil emulsion template. Photocatalytic degradation experiments were conducted through exposure of a methylene blue solution to UV light. The hybrid microbeads performed better than ZnO powder at the same initial dye and ZnO concentration because of higher adsorption and degradation. The initial concentration of dye solution and catalyst dosage have a significant impact on the degradation. Higher degradation is seen with lower initial dye concentration and higher catalyst dosage. The presence of magnetic nanoparticles within the beads allows for their full recovery and reuse for degradation experiments. Complete degradation of dye was achieved using the new ZnO/Fe3O4/SiO2 microbeads.

Boosting the photocatalytic activity of bismuth vanadate (BiVO4) via optimization of the internal polarization

Photocatalytic performance can be improved by optimizing the morphology and surface texture of the photocatalyst or forming different p-n and/or n-n heterojunctions. Although the heterojunction system enhances photocatalytic property; however, an internal spontaneous polarization electric field may be much more effective due to the separation of electron-hole pairs when the polarization field forces them to move in different directions. The present study demonstrated this insight where the BiVO4 synthesis condition and polarization field forces were controlled via homogeneous precipitation in the presence of polyvinylpyrrolidone (PVP). The as-synthesized BiVO4 photocatalysts' structure and morphology were investigated using XRD, SEM, Raman, DRS, and PL. The result revealed that the increase of PVP concentration reformed the shaping to the truncated bipyramid-like shape and creates a spontaneous internal polarization that enhanced BiVO4 photocatalytic performance. The photocatalytic activity of BiVO4 was evaluated by monitoring the photocurrent enhancement using chronoamperometry, electrochemical impedance spectra and the photodegrading of methylene blue (MB) aqueous solution to harmless compounds in the presence of light. The spontaneous polarization between the different facets of BiVO4 crystal enhances the e−/h+ separation during internal facets homojunction and leads to four times photocurrent enhancement and the MB photocatalytic degradation rate increased from 0.43 to 1.92 min−1.

Photocatalytic Activities of Methylene Blue Using ZrO2 Thin Films at Different Annealing Temperatures

Tetragonal ZrO2, synthesized by the sol–gel method and dip-coating technique, was found to be photocatalytically active for the degradation of methylene blue. The ZrO2 thin films were characterized by X-ray diffraction (XRD), Raman spectroscopy, Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and UV-vis spectroscopy. The photocatalytic degradation of methylene blue was carried out with this material. We identified the tetragonal phase in ZrO2 thin film at different annealing temperatures from 400 °C to 550 °C. The XRD study indicated that the films were monocrystalline in nature with preferred grain orientation along (011) plane and exhibited a tetragonal crystal structure. The crystallite size of the films increased with increasing annealing temperature. FTIR explained the bonding nature and confirmed the formation of the composite. UV-Vis showed the optical absorbance was high in the visible region and the optical band gap value increased with annealing temperature. The photocatalytic experimental results revealed that ZrO2 thin films degraded MB by 20%, 24%, 29%, and 36%, with annealing temperatures of 400 °C at 550 °C for 10 h, respectively. Our results provide useful insights into the development of photocatalytic materials and degradation of methylene blue.

Rational design of CdS-enwrapped polypyrrole nanoparticles for wastewater treatment: removal of hazardous pollutants in aqueous solutions.

The modern world requires a chemical industry that can run at low production costs while producing high-quality products with minimal environmental impact. The development of environmentally friendly, cost-effective, and efficient wastewater treatment materials remains a majorproblem for the sustainable approach. We prepared nanoscale cadmium sulfide (CdS)-enwrapped polypyrrole (PPy) polymer composites for degradation of organic pollutants. The prepared CdS@PPy nanocomposites were characterized by powder X-ray diffraction, scanning electron microscope (SEM), field emission scanning electron microscope (FESEM), Fourier transform infrared spectroscopy (FTIR), and ultraviolet-visible(UV) absorption spectroscopy, indicating proper intercalation between CdS and PPy. Consequently, the catalytic efficiency of the synthesized hybrid nanocomposites was analyzed through the degradation of methylene blue (MB) and rhodamine B (Rh B) under visible light irradiation. The measured degradation efficiency of the dye solutions under the photolysis process is about 18% and 23% for MB and Rh B dye, respectively. Furthermore, the recycle test result concludes that the CdS@PPy composite exhibits 91% and 89% of MB and Rh B dye degradation efficiency even at the 4th cycle, respectively. The positive synergistic impact of CdS and PPymay be the result of effective photocatalytic degradation of MB and RhB.

Sol-Gel Multilayered Niobium (Vanadium)-Doped TiO2 for CO Sensing and Photocatalytic Degradation of Methylene Blue.

Multilayered TiO2 films doped either with Niobium or Vanadium (1.2 at. %) were deposited by the sol-gel dip coating method on c-Si and glass substrates. The films on glass substrates were tested for CO sensing and photocatalytic degradation of methylene blue. X-ray diffraction data analysis showed that all the TiO2:Nb(V) films were nanocrystalline in the anatase phase, with a uniform and compact microstructure and a homogeneous superficial structure of small grains with diameters in the range of 13-19 nm. For the electrical characterization, the TiO2:Nb(V) films were incorporated in Metal-Insulator-Semiconductor (MIS) structures. The specific resistivity is of the order of 104 Ωcm and its value decreases with increasing the electrical field, which testifies to the injection of electrons into these layers. From the analysis of the current-voltage curves taken at different temperature- and frequency-dependent capacitance-voltage and conductance-voltage characteristics, the density and parameters of deep levels in these TiO2 films are evaluated and the electron charge transport mechanism is established. It was shown that the current in these TiO2:Nb(V)-Si MIS structures is mainly carried out by inter-trap tunneling via deep levels energetically distributed in the TiO2 bandgap. Testing these sol-gel TiO2:Nb(V) layers for gas sensing and photocatalytic capabilities proved that they could serve such purposes. In particular, the results of the V-doped sol-gel TiO2 film confirm its CO detection capability, which is rarely reported in the literature. For the photodegradation of methylene blue, the Nb-doped TiO2 samples were superior, with nearly double the photocatalytic efficiency of undoped TiO2.

Enhancing Methylene Blue Removal through Adsorption and Photocatalysis-A Study on the GO/ZnTiO3/TiO2 Composite.

This study focuses on synthesizing and characterizing a graphene oxide/ZnTiO3/TiO2 (GO/ZTO/TO) composite to efficiently remove methylene blue (MB) from water, presenting a novel solution to address industrial dye pollution. GO and ZTO/TO were synthesized by the modified Hummers and sol-gel methods, respectively, while GO/ZTO/TO was prepared using a hydrothermal process. The structural and surface properties of the composite were characterized using various analytical techniques confirming the integration of the constituent materials and suitability for dye adsorption. The study revealed that GO/ZTO/TO exhibits an adsorption capacity of 78 mg g-1 for MB, with only a 15% reduction in adsorption efficiency until the fifth reuse cycle. Furthermore, the study suggests optimal adsorption near neutral pH and enhanced performance at elevated temperatures, indicating an endothermic reaction. The adsorption behavior fits the Langmuir isotherm, implying monolayer adsorption on homogeneous surfaces, and follows pseudo-second-order kinetics, highlighting chemical interactions at the surface as the rate-limiting step. The photocatalytic degradation of MB by GO/ZTO/TO follows pseudo-first-order kinetics, with a higher rate constant than that of GO alone, demonstrating the enhanced photocatalytic activity of the composite. In conclusion, GO/ZTO/TO emerges as a promising and sustainable approach for water purification, through an adsorption process and subsequent photocatalytic degradation.

A novel sonoelectrochemical approach for preparing of ZnO nanoparticles

A novel, rapid, and facile method for one-step sonoelectrochemical synthesis of zinc oxide nanoparticles (UEZ) was introduced in this study. The optimum operating parameters have been selected at a voltage of 7.5 V, KCl concentration of 0.5 M, and the reaction time of 60 min. The as-prepared UEZ were characterized by XRD, SEM, and HRTEM. It was found that the UEZ has a hexagonal wurtzite structure with high crystalline quality, good purity, a size range of 30–100 nm, and good photocatalytic degradation of methylene blue. This work provides a facile route for large-scale synthesizing ZnO nanoparticles via anodization.

Biogenic synthesis of Ag-doped TiO2 photocatalyst using citrus paradisi extract for solar trigged degradation of methylene blue

The world has witnessed substantial deterioration of water resources by different effluents. The most reported among effluents that have caused damage to the water resources are azo dyes that need to be expelled by most efficient techniques such as photocatalysis. This specific study has focused on the synthesis and augmentation of TiO2 for the degradation of methylene blue (MB). In this work TiO2 was synthesized by biogenic route using the extract of Citrus paradisi and the synthesized metal oxide (TiO2) was doped with Ag to escalate the photocatalytic degradation of MB. The synthesized biogenic photocatalyst was characterized by employing XRD and FTIR techniques, which confirms the purity of TiO2. The stability of Ag-doped TiO2 photocatalyst was investigated by performing Zeta-potential and the surface morphology was studied thorough FE- SEM. The photocatalytic efficiency of the photocatalysts were evaluated using UV-vis-Spectroscopy. The XRD analysis confirmed the phase purity of synthesized TiO2 and Ag-doped TiO2. The presence of functional groups associated with the TiO2 and Ag-doped TiO2 were also observed through FTIR. The developed photocatalysts via biogenic route were tested for the degradation of MB that exhibited 56.38% for TiO2 and 85.55% Ag-TiO2 in 120mins respectively.

Synthesis of Reusable CNF/Ag2Se Films as Visible-Light-Driven Photocatalysts for Photocatalytic Degradation of MB

AbstractIn our study’s scenario, flexible films were fabricated from TEMPO-oxidized cellulose nanofibers and silver selenide (CNF/Ag2Se) as efficient membranes for the degradation of methylene blue (MB). Different concentrations of Ag2Se particles were in situ prepared in the presence of CNF. The in-situ synthesis of Ag2Se nanoparticles in the presence of CNF was reported as efficient technique for the formation of submicrosize Ag2Se particles with a narrow size distribution and homogeneous dispersion onto CNF. TEM analysis revealed that the nanofibers had uniform width and diameter, while XRD demonstrated single-phase orthorhombic β-Ag2Se formation. 3D-FESEM showed tiny root measurer values of 28, 30, and 32.56 nm in polymeric films with 2.5, 5, and 10% Ag2Se-filled CNF. Polymeric films had visible-driven-light photocatalytic activity because the band gap fell from 4.61 eV (UV area) to 2.71 eV (visible region). The composite’s photocatalytic performance was assessed by MB degradation. 10% of CNF/Ag2Se demonstrated maximal photocatalytic activity under simulated sunlight for 60 min, pH 9, and 3 g/L composite weight. The factorial design statistical analysis showed that MB dye photodegradation is mostly affected by irradiation time and dye concentration. Environmental, social, and economic factors are all considered, making this study suitable for implementing photocatalysis to large-scale water treatment systems, which is a key component of sustainability.

Photocatalytic Degradation of Methylene Blue and Methyl Orange Dye by Using the Core-Shell Structure of Fe3O4@ZnS Nanoparticles

A straightforward and highly efficient method was developed for the synthesis of Fe3O4@ZnS core-shell nanoparticles (NPs). These synthesized materials were subsequently utilized for the photocatalytic degradation of methylene blue (MB) and methyl orange (MO) dyes. The structural characteristics of the prepared sample were meticulously investigated through X-ray diffraction (XRD) and field-effect scanning electron microscopy (FESEM). The XRD analysis confirmed the crystalline phase formation in the Fe3O4 nanoparticles, while a study in the Vibrating Sample Magnetometer (VSM) mode emphasized their strong ferromagnetic behavior. The degradation of dyes was comprehensively studied using UV-Vis analyses, taking into account factors such as pH and initial dye concentration in the decolorization process. The synthesized Fe3O4@ZnS core-shell nanostructure underwent thorough characterization using XRD, UV-Vis spectroscopy, SEM, Fourier-transform infrared spectroscopy (FT-IR), and VSM mode in PPMS. Furthermore, the reusability of the catalyst was explored, yielding promising results. The findings demonstrated the efficient photocatalytic degradation of MB and MO dyes under UV-visible irradiation, achieving significant results within 30-minute intervals.

Liquid-phase controlled synthesis of Sb-derived heterostructures

Antimony (Sb) based compounds such as Sb2O3 and Sb2S3 have shown promises in electronics, catalysis and sensing devices. Their functional performances can be further improved by integration with other materials to from composites or heterostructures, which however, usually require tedious procedures with poor morphology control. Herein, we realized direct hydrothermal synthesis of Sb2O3/SnO2 heterostructures and Sb2S3/SnS2 heterostructures by using liquid-phase exfoliated two-dimensional (2D) Sb nanoflakes as precursors. Compared to directly using SbCl3 salt as the reactant, using the Sb nanoflakes enabled the slow release of Sb3+ ions which benefited the better controlled nucleation and growth of Sb2O3 (or Sb2S3) acting as growth templates for the further deposition of SnO2 (or SnS2). As a demonstration, the as-prepared Sb2S3/SnS2 heterostructures were employed for photocatalytic methylene blue (MB) degradation, which exhibited a faster degradation rate compared to Sb2S3 or SnS2 alone. Our work offers an alternative strategy with elemental 2D materials as precursors for the preparation of heterostructured functional materials.

Amphi-Luminescent MoS2 nanostructure for photocatalytic splitting of water and removal of Methylene Blue

Chemical dyes used in the textile industries are one of the major pollutants in water. Methylene blue (MB) is a commonly seen dye that creates hazardous health problems. In this article the photocatalytic degradation of MB by the nanocatalyst MoS2 (Nano-MoS2) and carbon dot (C Dots) incorporated MoS2 (Nano-CD-MoS2) is reported. The photocatalytic degradation of MB is analyzed based on the electron-hole recombination rate of the catalyst. Photoluminescence emission exhibited by the catalyst is used as a key indicator to probe the electron-hole recombination rate. Nano-MoS2 was synthesized hydrothermally at 180 0C for 8 h from ammonium tetra thiomolybdate (ATTM). C Dot was prepared following a green root from ash guard extract which later mixed with Nano-MoS2 and kept in an autoclave at a temperature 140 °C for 4 h to get Nano-CD-MoS2. The photoluminescence (PL) and photocatalytic behavior of Nano-MoS2 and Nano-CD-MoS2 and their application for water splitting and water purification are reported. The incorporation of graphene and artificial C Dot into MoS2 nanostructures are reported to increase the conductivity and active edge sites of MoS2 that enhances the photocatalytic action. Since green C Dots are eco-friendly and easily synthesizable than artificial C Dots, as a novel study, this article investigated the influence of green C Dots on the PL and photocatalytic performance of nanosized MoS2. Nano-MoS2 and Nano-CD-MoS2 exhibited both upconversion and downconversion PL; accordingly the nanostructures were termed as amphi-luminescent. The amphi-luminescence property widens the photon absorption range and hence enhances the catalytic degradation of dyes. Nano-MoS2 which exhibited lesser intensity of amphi-luminescence emission compared to Nano-CD-MoS2 showed better results in degradation of MB. C Dots may bind with the valence band electrons of MoS2, resulting in the reduction of dangling bonds. Dangling bonds can trap photo-induced excitons to hinder the rate of electron-hole recombination. So, fast electron-hole recombination occurs in Nano-CD-MoS2 than Nano-MoS2. Fast electron-hole recombination supports radiative electron-hole recombination while suppresses the non-radiative energy transfer of electrons and causes high PL intensity. However, according to the energy level diagram, Nano-MoS2 with minimal electron-hole recombination rate is more favorable for O2/O2–,.OH/ OH– and.OH/H2O reactions that facilitate MB degradation. Photocatalytic activity of catalysts were confirmed by measuring the photocurrent from a simple custom-made two-electrode water photolysis cell where the nanocatalysts were dispersed in electrolyte. Lead and steel rods were used as electrodes. Multimeter was used to measure current. Nano-MoS2 exhibited better performance with a maximum photocurrent of 141 µA. Influence of green C Dots in energy levels, PL and photocatalysis of MoS2 and mechanisms of PL and degradation of MB are thoroughly investigated in this article.

Enhancing the Photocatalytic Degradation of Methylene Blue with Graphene Oxide-Encapsulated g-C3N4/ZnO Ternary Composites.

Methylene blue (MB) is a toxic contaminant present in wastewater. Here, we prepared various composites of graphene oxide (GO) with graphitic carbon nitride (g-C3N4) and zinc oxide (ZnO) for the degradation of MB. In comparison to ZnO (22.9%) and g-C3N4/ZnO (76.0%), the ternary composites of GO/g-C3N4/ZnO showed 90% photocatalytic degradation of MB under a light source after 60 min. The experimental setup and parameters were varied to examine the process and effectiveness of MB degradation. Based on the results of the experiments, a proposed photocatalytic degradation process that explains the roles of GO, ZnO, and g-C3N4 in improving the photocatalytic efficacy of newly prepared GO/g-C3N4/ZnO was explored. Notably, the g-C3N4/ZnO nanocomposite's surface was uniformly covered with ZnO nanorods. The images of the samples clearly demonstrated the porous nature of GO/g-C3N4/ZnO photocatalysts, and even after being mixed with GO, the g-C3N4/ZnO composite retained the layered structure of the original material. The catalyst's porous structure plausibly enhanced the degradation of the contaminants. The high-clarity production of g-C3N4 and the effectiveness of the synthesis protocol were later validated by the absence of any trace contamination in the energy-dispersive X-ray spectroscopy (EDS) results. The composition of the ZnO elements and their spectra were revealed by the EDS results of the prepared ZnO nanorods, g-C3N4/ZnO, and GO/g-C3N4/ZnO. The outcomes indicated that the nanocomposites were highly uncontaminated and contained all necessary elements to facilitate the transformative process. The results of this experiment could be applied at a large scale, thus proving the effectiveness of photocatalysts for the removal of dyes.

Green synthesis of ZnO-doped cerium oxide nanocomposite using clove extract: enhanced photocatalytic methylene blue degradation and antibacterial properties

Green synthesis of ZnO-doped cerium oxide nanocomposite using clove extract: enhanced photocatalytic methylene blue degradation and antibacterial properties

Green synthesis of Ag nanoparticles from Verbascum insulare Boiss. and Heldr.: Evaluation of antimicrobial, anticancer, antioxidant properties and photocatalytic degradation of MB

In recent years, due to the environmental friendliness of nanoparticle production, biosynthesis methods using plant extracts and possible physical, chemical, thermal and biological properties of the synthesized nanoparticles are frequently the subject of research. In the present study, hydrothermally assisted synthesis of Ag nanoparticles using twig-leaf extract of Verbascum insulare Boiss. and Heldr., (VIE-AgNPs) a plant endemic to Turkey, was successfully carried out for the first time in this study. The presence of 24 of the 53 phytochemicals investigated in the content of the extract of Verbascum insulare Boiss. and Heldr. (VIE) determined by the LC-MS/MS system was detected. In addition, the amount of phenolic substance involved in reduction was found to be 60.42 ± 9.11 µg Gallic acid equivalent/mg-extract. The synthesized AgNPs were characterized by UV–visible spectra (UV–vis), scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), Fourier transforms infrared spectroscopy (FTIR), and X-ray diffraction (XRD). In particular, the surface plasmon band observed at 422 nm, the characteristic peaks observed in XRD, and the bond energy values seen in XPS strongly confirmed the formation of AgNPs. XRD and TEM data showed that AgNPs had an average size range of 25–30 nm. FTIR data indicated the presence of some herbal agents on the surface of AgNPs. The properties of the VIE-AgNPs were compared in vitro with chemically produced AgNPs (C-AgNPs). The OSI level of C-AgNPs was 87.78 ± 1.75 AU, while that of VIE- AgNPs was 110.42 ± 7.54 AU. It was observed that the nanoparticle and VIE used in the study had antimicrobial activity. It was determined that its antibacterial activity was stronger than its antifungal activity. When the analyzed inflammatory parameter levels (TNF-α, IL1β, TGF-β, and DEF-β2) were examined, the effect of VIE on inflammation in A549 cells could not be detected. However, it was determined that VIE-AgNPs, one of the nanoparticles used in the study, increased anti-inflammatory levels more than C-AgNPs. When the received data are evaluated together, it can be said that biosynthesized AgNPs suppress proliferation and stimulate apoptosis in cancer cells by increasing oxidative stress and inflammation levels compared to chemical AgNPs, thus showing an anticarcinogenic effect. It was found that VIE-AgNPs could effectively degrade the water pollutant methylene blue (MB) dye. VIE-AgNP mediated 78 % photocatalytic degradation of MB in 180 min. All superior biological properties are thought to be due to the low particle size and the interaction of active components with AgNPs during the biosynthesis process. Because it has been observed that VIE-AgNPs, which have a smaller particle size, have higher biological (cytotoxic, anticarcinogenic, inflammatory, etc.) activities than C-AgNPs. It can be said that AgNPs produced by biosynthesis may have potential use in the production of environmentally friendly, antibacterial/anticarcinogenic materials.

Dinuclear cadmium(II) complexes with distorted octahedral/monocapped trigonal prism coordination geometries: synthesis, crystal structure, DFT/TD-DFT calculation and photocatalytic degradation of methylene blue

Two Cd(II) complexes [Cd2(L1)2(dca)(NO3)] (1) and [Cd2(L2)2(SCN)(NO3)] (2) (HL1 = 2-methoxy-6-[(2-phenylamino-ethylimino)-methyl]-phenol; and HL2 = 2-[(2-ethylamino-ethylimino)-methyl]-6-methoxy-phenol), have been synthesized and characterized by single crystal structure analysis, IR and mass spectroscopic studies. Both the complexes 1 and 2 possess a triclinic crystal system with space group P1¯. In complex 1, geometry around one metal centre is distorted octahedral and other centre is distorted monocapped trigonal prism, whereas in complex 2, both the metal centres possess distorted octahedral geometries. Strong NH⋅⋅⋅O and weak aromatic CH⋅⋅∙O hydrogen bonding interactions in 1 and strong NH⋅⋅⋅O and NH⋅⋅⋅S hydrogen bonding in 2 results 1D and 2D supramolecular structures, respectively. Experimentally determined electronic spectral data have been compared with the calculated data obtained by DFT and TD-DFT calculation. Photocatalytic abilities of 1 and 2 have been examined by using spectroscopic technique and found that in presence of UV light both the complexes catalytically decomposed methylene blue by 54.0 % and 50.3 %, respectively.

Synthesis of novel Ag/AgBr/K0.4Y0.7Sb2O6.25 nanocomposite with enhanced photocatalytic properties

Devoloping efficient wastewater treatment photocatalysts capable of improving water quality is undoubtedly one of the main problems of present society. In recent years, novel plasmonic photocatalysts have shown new possible applications in photocatalytic wastewater treatment due to their unique properties. In this work, a novel Ag/AgBr/K0.4Y0.7Sb2O6.25 composite was successfully fabricated by photo-reduction using the pre-prepared AgBr/K0.4Y0.7Sb2O6.25 and K0.4Y0.7Sb2O6.25 (KYSbO). The AgBr/KYSbO and KYSbO were synthesized by deposition-precipitation and precipitation-heating methods. The visible-light photocatalytic performance of parent KYSbO and Ag/AgBr/KYSbO composite was evaluated using methylene blue (MB) as a model organic pollutant. The effects of catalyst dosage, pH and the initial concentration of the MB dye solution on the photocatalytic activity were also investigated in this study. Remarkably, the Ag/AgBr/KYSbO composite exhibited superior visible-light photocatalytic activity for the degradation of MB than that of parent KYSbO. MB was degraded to 91.6% in the presence of parent KYSbO after visible irradiation of 180 min, while 93.2% degraded in merely 30 min in the case of Ag/AgBr/KYSbO composite. The superior improvement in the photocatalytic activity of the Ag/AgBr/KYSbO composite can be credited to the efficient separation of photoinduced electron-hole pairs and the extended visible-light response range. Superoxide radicals are crucial for MB photocatalytic degradation in the Ag/AgBr/KYSbO composite. The possible photocatalytic mechanism was proposed.

A new approach to the synthesis of CuMoO4 nanoparticles with mechanistic insight into the sunlight-assisted degradation of textile pollutants and antibacterial activity evaluation

CuMoO4 nanoparticles (NPs) were synthesized by a thermal decomposition followed by a precipitation method. Analytical techniques such as SEM, EDS, TEM, XRD, FTIR, UV-visible, PL, and XPS were employed to characterize the structural, optical and photocatalytic properties of CuMoO4. As per XRD analysis, CuMoO4 with different Cu concentrations were consistent, however, their crystallinities were changed. The band gap of CuMoO4 with various concentrations of Cu (0.1, 0.2, and 0.3M) was estimated to be 1.97eV, 1.86eV, and 1.44eV, respectively. The electrical conductivity of 0.3M CuMoO4 NPs was greater than other nanocomposites. Methylene Blue (MB) mineralization in an aqueous medium after 180minutes of exposure to sunlight was investigated to study the photocatalytic activities of all CuMoO4 composites. As per the PL study, the 0.3M CuMoO4 NPs exhibited better photocatalytic efficiency due to their low electron-hole recombination rate. Experimental parameters like the MB concentration, catalyst dosage, and the solution pH were evaluated to optimize the experimental conditions. The in-situ capture analysis proposed a plausible mechanism for the photocatalytic degradation of MB. The two main active species identified for MB degradation were superoxide radical anions and hydroxyl radicals. The repeated photocatalytic MB degradation verified the high level of reusability of 0.3M CuMoO4. The well-diffusion technique was utilized to examine the antibacterial activity of 0.3M CuMoO4 NPs against gram-positive (Salmonella typhi) and gram-negative (Streptococcus mutans) bacterial strains. Optimized CuMoO4 showed excellent promise for application in the field of photocatalysis, electrocatalytic and antibacterial activity.

Synthesis of carboxylated cellulose nanocrystal/ZnO nanohybrids using Oxytenanthera abyssinica cellulose and zinc nitrate hexahydrate for radical scavenging, photocatalytic, and antibacterial activities

The extremely low antioxidant, photocatalytic, and antibacterial properties of cellulose limit its application in the biomedical and environmental sectors. To improve these properties, nanohybrides were prepared by mixing carboxylated cellulose nanocrystals (CCNCs) and zinc nitrate hexahydrate. Data from FTIR, XRD, DLS, and SEM spectra showed that, ZnO nanoparticles, with a size ranging from 94 to 351 nm and the smallest nanoparticle size of 164.18 nm, were loaded onto CCNCs. CCNCs/ZnO1 nanohybrids demonstrated superior antibacterial, photocatalytic, and antioxidant performance. More considerable antibacterial activity was shown with a zone of inhibition ranging from 26.00 ± 1.00 to 40.33 ± 2.08 mm and from 31.66 ± 3.51 to 41.33 ± 1.15 mm against Gram-positive and Gram-negative bacteria, respectively. Regarding photodegradation properties, the maximum value (~91.52 %) of photocatalytic methylene blue degradation was observed after 75 min exposure to a UV lamp. At a concentration of 125.00 μm/mL of the CCNC/ZnO1 nanohybrids sample, 53.15 ± 1.03 % DPPH scavenging activity was obtained with an IC50 value of 117.66 μm/mL. A facile, cost-effective, one-step synthesis technique was applied to fabricate CCNCs/ZnO nanohybrids at mild temperature using Oxytenanthera abyssinica carboxylated cellulose nanocrystals as biotemplate. The result showed that CCNCs/ZnO nanohybrids possess potential applications in developing advanced functional materials for dye removal and antibacterial and antioxidant applications.