Decomposition Of Dye Research Articles

Low-frequency contact-electro-catalysis driven by friction between the PTFE-coated fabric and dye solution

The process of contact electrification occurs when two materials with dissimilar work functions are in contact and charged. Contact-electro-catalysis may occur when electron exchange at the liquid-solid interface initiates a redox reaction. This type of catalysis falls under the mechanically-driven tribocatalysis and has been demonstrated to be able to degrade dye under high-frequency ultrasonic excitation. In this work, a high RhB dye decomposition ratio of 91.5% is achieved by harnessing the ordinary low-frequency solid-liquid friction energy through the design and use of the recyclable fabric with PTFE coating as a solid friction source to agitate the dye solution. In the absence of PTFE coating, the RhB dye decomposition ratio is about 14.8% under the same friction conditions. The enhanced contact-electro-catalysis may be attributed to the high electronegativity of PTFE coating. According to the quenching experiments with active species, it is found that hydroxyl radical (·OH) and superoxide radical (·O2-) are the main active species induced by low-frequency solid-liquid friction. The fabric with PTFE coating after being dried and reused for 5 cycles still possesses 87.9% RhB dye decomposition ratio. With these advantages of high decomposition ratio of organic pollution, low cost, good recyclability, and environmental friendliness, the developed low-frequency contact-electro-catalysis in this work, is potential for organic wastewater treatment application through utilizing waste solid materials to harvest the mechanical friction energy between solid waste fabrics and ordinary waterflow in future.

Ultrasound-Assisted Advanced Oxidation Process Using Perovskite-Type LaMnO3 Nanospheres.

Among the perovskite oxide community, La-based perovskites have garnered considerable interest due to their remarkable properties including catalytic, electrocatalytic, photocatalytic, sensing, electrical, magnetic, and optical characteristics. Herein, rhodamine-B (RB) dye has been reported to be sono-catalytically decomposed by an ultrasound-assisted advanced oxidation process (AOP) using perovskite-type LaMnO3 (LMO) nanospheres synthesized via ultrasonic approach. Several physiochemical characterizations such as XRD, FT-IR, XPS, SEM, TEM, and SEM-EDS investigations were used to investigate the LMO perovskite nanospheres. Then, LMO potential for adsorption and the sonocatalytic decolorization of RB dye in an aqueous solution are examined. With LMO perovskites, the adsorption and removal kinetics of RB correspond to the pseudo-first-order model. Furthermore, by utilizing the pseudo-first-order, the RB dye process is removed with improved efficacy in the following sequence: Agitation alone: 3.76×10-4 min-1<US only: 5.02×10-3 min-1<LMO only: 5.85×10-3 min-1<LO@MO + US: 1.38×10-2 min-1<LMO + US: 1.75×10-2 min-1, accordingly. Perovskite-type LMO, which has significant reusability and stability, is an ensuring sonocatalyst for dye decomposition in wastewater, enabling faster decolorization. A prospective mechanism has been suggested for the sonocatalytic decomposition of RB.

Synthesis of TiO2-brookite nanorods and TiO2-Au composites for decomposition of organic dyes in water

This study employed a plasma-liquid interaction technique at room temperature to modify TiO2 nanocrystals in the brookite phase and coat their surface with gold nanoparticles (AuNPs). The technique was further utilized to reduce Au3+ ions to Au0, eliminating the need for chemical agents and reducing reaction time. The resulting TiO2-Au photocatalysts were then tested under visible light to evaluate their ability to degrade the dyes rhodamine 101 (RB101) in water. The findings indicated that the most effective degradation of RB101 molecules occurred at low dye concentrations (10 ppm) and low photocatalyst loadings with a ratio of 4. In comparing two different preparation methods, the TiO2-Au sample created using a micro-plasma process with a direct current (DC) source exhibited higher photocatalytic activity (87 % after 4 hours) compared to the sample created using a plasma jet process with an alternating current (AC) source. This research holds significance for the advancement of photocatalytic materials with potential environmental applications.

Green synthesis of ZnO, Fe3O4, and TiO2 nanoparticles: exploring enhanced bacterial inhibition, catalysis, and photocatalysis for sustainable environmental applications

ABSTRACT This study investigates the physicochemical and biological properties of metal oxide nanoparticles (TiO2, ZnO, and Fe3O4) synthesised via the phytosynthesis method using an extract from Boerhaavia diffusa leaves (BDL). The proteins and phenols present in the BDL extract played essential roles in reducing and stabilising TiO2, ZnO, and Fe3O4 nanoparticles. The study reveals size-dependent morphological, structural, and biological characteristics of the produced nanoparticles. FTIR spectra confirm the involvement of BDL extract in the synthesis process of TiO2, ZnO, and Fe3O4 nanoparticles. Transmission electron microscopy (TEM) analysis of TiO2 nanoparticles identified small, spherical particles (9 nm in diameter). BDL-derived TiO2, ZnO, and Fe3O4 demonstrated significant photocatalytic activity, achieving degradation rates of 98.96%, 96.26%, and 94.42%, respectively, in the decomposition of mono-azo dye after 40 minutes of UV irradiation. The reaction rates for BDL-derived TiO2, ZnO, and Fe3O4 were 0.367/min, 0.186/min, and 0.061/min, respectively, when catalysing the reduction of 4-Nitrophenol (4-NP) to 4-Aminophenol using NaBH4. BDL-derived TiO2 nanoparticles exhibited significant antibacterial effectiveness, showing a 23.6 mm zone of inhibition against Salmonella typhi. The BDL-derived TiO2, ZnO, and Fe3O4 nanoparticles exhibited remarkable cytotoxicity against lung cancer cell lines with IC50 values of 76.36 µg/mL, 90.21 µg/mL, and 94.61 µg/mL, respectively. This study reveals the potential of BDL-derived TiO2, ZnO, and Fe3O4 nanoparticles for applications in antibacterial, anticancer, catalytic, and photocatalytic fields, contributing to sustainable development of multifunctional nanomaterials for various technical and environmental advancements.

Preparation, characterization and emission of Na3-3xLnxFe2(PO4)3 (Ln = Eu, Tb; 0 ≤ x ≤ 0.1 mol %) and photocatalytic activity of Na3Fe2(PO4)3

Rare earth doped compositions Na3-3xLnxFe2(PO4)3 (x = 0, 0.025, 0.05, 0.075 and 0.1) were prepared by ion-exchange method using Na3Fe2(PO4)3 and LnCl3 (Ln = Eu and Tb). Pristine Na3Fe2(PO4)3 was obtained by ethylene glycol assisted gel burning procedure. The phase characterization was performed by powder X-ray diffraction (XRD). All the compositions were well crystalized in monoclinic lattice. The FE-SEM images and elemental mapping were obtained. The infrared and Raman profiles of all-compounds were dominated by the bands owing to the (PO4) units. Investigation on photoluminescence emission and excitation spectra of Ln3+ (Ln = Eu, Tb) were carried out. The excitation spectra of Na3-3xLnxFe2(PO4)3 (Ln = Eu and Tb) gave intensive band at 256 (370) nm for Eu (Tb) doped phosphors. The photoluminescence emission spectra of Ln3+ (Ln = Eu, Tb) were carried out. The emission spectra of these composition were characterized by f -f transitions corresponding to 613 (5D0→7F2) for Eu and 543 (5D4→7F5) for Tb doped compositions. The maximum emission intensity for Eu (Tb) doped phosphors was found at x = 0.075 (0.05). The analysis of CIE and CCT values of all prepared phosphors were also carried out. Decay curves were analyzed in detail. The visible-light photo-catalytic activity of parent Na3Fe2(PO4)3 was examined against decomposition of methylene blue and methyl orange dyes. Parent Na3Fe2(PO4)3 exhibits good efficiency against MB (≈94.5 %) and moderate efficiency against MO (≈64 %) in 180 min of visible light irradiation. Scavengers’ experiments were carried to identify the active species during photodegradation.

Microwave-Assisted Hydrothermal Synthesis of Photocatalytic Truncated-Bipyramidal TiO2/Ti3CN Heterostructures Derived from Ti3CN MXene.

TiO2/MXene heterostructure has garnered significant interest as a photocatalyst due to its large surface area and efficient charge carrier separation at the interface. However, current synthesis methods produce TiO2 without clear crystal faceting and often require complicated postprocessing step, limiting its practical applications. We demonstrate a facile and controlled microwave-assisted hydrothermal synthesis for transforming multilayered Ti3CN MXene to a truncated-bipyramidal TiO2/Ti3CN heterostructure. The resulting TiO2 nanocrystals at the Ti3CN surface exhibited crystalline anatase truncated bipyramids, exposing {001} and {101} facets. We further tailored an indirect optical band gap of the TiO2/Ti3CN heterostructure in the range of 3.17-3.23 eV by varying the hydrothermal synthesis time from 15 min to 5 h at a fixed temperature of 160 °C. Efficient charge separation allowed us to decompose 97% of methylene blue (MB) within 30 min of ultraviolet (UV) light irradiation, ∼3.9-fold faster than the benchmark P25, higher than any other TiO2/MXene heterostructures. With simulated white light, we achieved over 60% efficiency of the dye decomposition within 2 h of irradiation, which resulted in 1.5-fold faster kinetics than P25. We also observed a similar excellent performance of Ti3CN-derived TiO2 in decomposing various persistent synthetic dyes, including commercial textile dye, methyl orange, and rhodamine B. In conclusion, our study provides a strategy for utilizing MXene chemical reactivity to produce highly crystalline optically active TiO2/Ti3CN heterostructure. The developed heterostructure can serve as an efficient photocatalyst for the degradation of organic pollutants.

Sustainable Fabrication of Luminescent Zinc Oxide Nanoparticles From Cucumis melo Fruit Peel Extract as Prospective Photocatalytic and Antigermicidal Agent.

The focus of current advances in nanotechnology has shifted significantly towards environmentally conscious methods that use harmless ingredients and moderated reaction circumstances to promote equitable development. Zinc oxide nanoparticles (NPs) currently grabbed attention of multiple medical fields owing to their unique ability to safeguard against cellular damage and alleviate serious human diseases via processes related to metabolism. This work focused on the generation of ZnO NPs using the peel of Cucumis melo fruit. The NPs were then analyzed and characterized using UV-Vis spectroscopy. The results indicated that at a wavelength of 352 nm, it was proven that the biosynthesis of ZnO NPs had occurred. The XRD pattern indicated the presence of dense crystal structures. The field emission scanning electron microscope (FE-SEM) picture confirmed the existence of polygonal-shaped ZnO NPs. The findings indicate that the produced ZnO NPs possess tough antibacterial properties against Gram-positive and Gram-negative microorganisms. When the ZnO NPs were exposed to direct sunshine for 80 min, they showed an 89% dye breakdown efficiency. This research specifically focused on the decomposition of reactivity dyes, with methylene blue dye being used as the target dye. The work demonstrates that the biosynthesis of ZnO NPs has a crucial and versatile role in the biological and environmental sectors.

Kinetics of the decomposition of reactive black 5 on carbon nanostructured adsorbents

Textile industry effluents, containing vast quantities of toxic organic pollutants and synthetic dyes like Reactive Black 5 (RB5), pose a significant environmental threat. RB5 contamination can harm ecosystems and human health, necessitating effective treatment for water recycling and compliance with quality standards. Traditional methods like filtration often fall short in removing dye chemicals. This study examines the efficiency of nanocarbon-based adsorbents in removing RB5 from textile industry effluents. RB5 solutions at concentrations of 10 µM, 30 µM, 60 µM and 100 µM were investigated and characterized using scanning electron microscopy (SEM) and UV-Vis spectrophotometry. Activated carbon (AC) demonstrated the highest degree of RB5 decomposition, outperforming graphene nanoplatelets (GNPs) and graphene oxide (GO) and offering a promising solution for mitigating textile wastewater pollution. Kinetic studies revealed that RB5 adsorption follows a pseudo-second-order model for all adsorbents. The rate constants were determined using PSO kinetics and they were comparable with the rate constants of prior studies, indicating the applicability of the model to the study of the kinetics of similar dye adsorption and decomposition processes.

Composite photocatalysts g-C&lt;SUB&gt;3&lt;/SUB&gt;N&lt;SUB&gt;4&lt;/SUB&gt;/TiO&lt;SUB&gt;2&lt;/SUB&gt; for hydrogen production and dye decomposition

The photocatalytic activity of the g-C3N4 /TiO2 composite samples in the processes of dye (methylene blue) decomposition and hydrogen evolution from an aqueous ethanol solution under the action of visible radiation (400 nm) has been studied. A new original method for the synthesis of the g-C3N4 /TiO2 composite by depositing g-C3N4 /TiO2 to TiO2 nanoparticles during sol-gel synthesis is proposed. The synthesized photocatalysts were characterized by X-ray diffraction, low-temperature gas adsorption, X-ray photoelectron spectroscopy, high-resolution transmission microscopy, and diffuse reflectance spectroscopy in the UV and visible regions. The maximum activity in the hydrogen evolution reaction was 1.3 mmol h–1, which exceeds the rate of hydrogen evolution on the unmodified g-C3N4 and TiO2 samples.

Effects of UV illumination on organic dye decomposition activity and antibacterial and antiviral activities of rare earth iodates

For this study, we investigated the effects of UV illumination on dye decomposition and antibacterial and antiviral activities of three rare earth iodates (Ce(IO3)4, Ce(IO3)3, and δ-La(IO3)3) that reportedly have antibacterial and antiviral activities in the dark. The objective of this study was to clarify whether bulk materials and eluted ions are involved in these activities under UV illumination. Findings indicate that Ce(IO3)3 and δ-La(IO3)3 exhibit dye degradation activity under UV illumination by a Hg-Xe lamp (7 mW/cm2), suggesting that the dye decomposition activity was caused mainly by photochemical reactions under UV with wavelengths less than 300 nm by Ce3+ and by IO3− ions eluted from the samples. The dye decomposition activity under UV illumination is expressed not only from the eluted ions but also from the bulk materials. UV illumination using a weak (0.1 mW/cm2) UV light from a black light bulb with wavelengths longer than 320 nm increased the antibacterial and antiviral activities of these materials. These results suggest that the increase in antibacterial and antiviral activities is attributable to the photocatalytic reaction of bulk materials. This study revealed that both the bulk and eluted ions are involved in these activities under UV illumination. The extent to which photochemical reactions caused by eluted ions and bulk material contribute to the decomposition activity of organic dyes and antibacterial and antiviral activities depends on the UV illumination wavelength and intensity. This study provides new insights into the use of rare earth iodates as inorganic antibacterial and antiviral materials.Graphical abstract

Green engineered Mo-CeO2@C nanocomposites for visible light-assisted dye decomposition and microbial apoptosis

The profound contamination of reservoirs triggered by industrial dyes and the growing phenomenon of antibiotic-resistant bacteria present substantial risks to both the environment and human health. Conventional approaches to water treatment and microbiological disinfection can frequently become ineffective, expensive, and detrimental to the environment, and this issue underscores the need for novel materials that possess refined photocatalytic and antibacterial characteristics that thrive efficiently in a setting of visible light. An innovative nanostructured nanocomposite, Mo-CeO2@C, was synthesized using a green chemistry method coupled with Mo-CeO2 nanoparticles and pristine CeO2. The impact of Ce, Mo, and carbon-based nanocomposites has been validated by leveraging XRD, FTIR, UV–vis spectra, and FE-SEM/EDX. The sunlight-mediated photodegradation performance of carbon-based nanocomposite exhibited a superior photodegradation efficiency of 99.5 %, higher than others. The photocatalytic activity of M.B. dye concentration, catalyst dosage, scavenger test, and recyclability were also conducted, which confirm the optimal catalyst loading of 20 mg, dye concentration 40 ppm, and pH 8 with reusability up to sixth cycles. The carbon-coated doped nanocomposite displays superior antibacterial efficacy against gram-positive S. aureus, gram-negative E. coli, and P. vulgaris bacteria in comparison to CeO2 and Mo-doped CeO2. This may be attributed to the combined effects of the generation of reactive oxygen species (R.O.S.) and the intrinsic characteristics of the dopant and carbon matrix. The results of our research emphasize the potential of carbon-based nanoparticles as versatile agents in the realms of environmental rehabilitation and biomedical research. These nanoparticles provide a method to achieve more efficient and resilient solutions in these areas.

Binary nano-systems TiO2-ZnO and TiO2-Cu in the chitosan matrix: synthesis and photocatalytic properties

Abstract Binary TiO2-ZnO and TiO2 - nanoparticles (NPs) Cu in a chitosan stabilizer matrix were obtained and studied as photocatalysts at their content relative to the mass of the dry polymer of 10 wt.%. The effect of the mass ratio of TiO2:ZnO, TiO2:Cu NPs was revealed on the photocatalytic properties of materials in the decomposition reaction of methylene orange when exposed to UV and visible light. It is shown that the greatest depth of decomposition of the azo dye - 98% – in an aqueous solution is achieved in 60 minutes of light exposure using the system TiO2:ZnO with a mass ratio of 1:1 and 2:1 components. The same level of photocathaitic activity – a decrease in the concentration of methylene orange by 95-98 % is achieved when using the system TiO2: Cu NPs at a mass ratio of 10:1 and 5:1 components.

Effect of post-annealing treatment on structural, optical and photocatalytic properties of TiO2 nanoparticles prepared via pulsed laser ablation in liquid

Ultrasmall TiO2 nanoparticles were synthesized through pulsed laser ablation of a metal titanium target in liquid followed by thermal annealing treatment. The impact of post-annealing treatment on the structural, morphological, optical properties, and the photocatalytic activity of the synthesized TiO2 nanoparticles have been investigated through a variety of analytical techniques, including X-Ray diffraction, transmission electron microscopy, ultraviolet-visible diffusion reflectance spectra, X-ray photoelectron spectroscopy. The results reveal that annealing temperature significantly improved the crystallinity of laser ablated TiO2 nanoparticles and modified the chemical states of surface elements. Defects introduced by laser ablation, which serve as electron traps, combined with enhanced crystallinity resulting from thermal annealing, have improved the photocatalytic degradation performance of TiO2 nanoparticles. Specifically, TiO2 nanoparticles annealed at 300 ℃ exhibited optimal photocatalytic performance in decomposition of model dye under the irradiation from xenon lamp, demonstrating the critical role of annealing in improving photocatalytic properties. This study not only broadens the comprehension of the impact of post-treatment on the characteristics of laser-ablated TiO2 nanoparticles nanoparticles but also highlights their potential for effective wastewater remediation.

Расчет параметров теплового взрыва нафтохинондиазидных фоторезистов на основе экспериментальных данных

The study is focused on the applied task of determination of self-ignition (flash) temperature of unstable substances in order to facilitate occupational safety without conducting large-scale experiments. For two representatives of a number of naphthoquinonediazides, semi-products of production of positive photoresists—monosodium salt 1,2- naphthoquinondiazide(2)-5-sulfonic acid (Dye M) and 1,2-naphthoquinondiazide(2)-5-sulfochloride (Dye N2), the applicability of the thermal explosion classic theory has been proved. Using experimental kinetic parameters and the heat of decomposition of dyes, parameters of a thermal explosion in adiabatic conditions and convective heat transfer conditions have been calculated. As the analysis of obtained dependences shows, the linear dependence of slow growth (induction period) with time transforms into exponential dependence for each substance. Notably, the heat resistance of Dyes М and N2 is rather low. It has been shown that the slow decomposition of substances in conditions of the missing heat sink can transform into the stage of thermal explosion. The design temperature of self-ignition (flash) of the substance calculated considering the heat sink and the geometry of process equipment is 135 °C for Dye М and 93 °C for Dye N2, which complies with the experimental data. The recommendations on the selection of safe temperatures for drying modes of the studied compounds have been provided.

Effect of laser power density on formation of oxide particles during ablation of metallic bismuth in atmospheric air

Purposeful synthesis of bismuth oxide nanoparticles (NPs) of various crystal modifications is important for biomedicine, photocatalysis and other applications. In this work, pulsed laser ablation of a metallic Bi target in atmospheric air is used to obtain β-Bi2O3 NPs. The effect of the Nd:YAG laser radiation power density (1064 nm, 7 ns) in the range of 0.1–1.2 GW/cm2 on the features of formation of NPs under nonequilibrium conditions is studied, for which the spectra of laser-induced plasma are recorded and analyzed, the plasma composition is determined, and the temperature of the plasma plume is estimated. The NPs are comprehensively characterized using TEM, XRD, FTIR, Raman, and UV–Vis spectroscopies, and electrophoretic light scattering, which make it possible to determine their morphology, crystal structure, chemical composition, and optical properties. The photocatalytic activity of the resulting nanopowders in the Rhodamine B dye decomposition reaction is assessed.

Ultrasonic assisted synthesis of nanoporous carbon/CeVO4 nanocomposite for supercapacitor and photocatalytic applications

Here, nanoporous carbon (NPC)/CeVO4 nanocomposite synthesized via ultrasonic assisted method for supercapacitor and tartrazine dye degradation application. Transmission electron microscope (TEM) studies confirmed the CeVO4 nanoparticles well embedded on the NPC surface in the NPC/CeVO4 nanocomposite. Spherical shaped CeVO4 nanoparticles are well incorporated on the surface of NPC therefore NPC/CeVO4 nanocomposite which possess a porous-like structure would improve the supercapacitor applications and dye degradation performance. As expected, the specific capacitance (Cs) values (555 F g−1) of NPC/CeVO4 nanocomposite showed enhanced performance as compared to CeVO4 nanoparticles (234 F g−1) at a current density of 1 A g−1 and the capacitance retention of the designed electrode as 95 % after 5000 cycles. The photodegradation of tartrazine dye using pure CeVO4 nanoparticles and NPC/CeVO4 nanocomposite was explored under visible light irradiation. The photocatalytic degradation experiment demonstrated that the NPC/CeVO4 exhibits the maximum degradation efficiency (98.76 %) of the tartrazine with was reached within 120 min. Moreover, the rate constant of NPC/CeVO4 for tartrazine dyes decomposition was 0.0192 min−1 representing that it is two-fold higher than pure CeVO4 (0.0073 min−1). The superior electrochemical and photocatalytic properties of NPC/CeVO4 nanocomposite have been observed due to the well-designed structure and high surface area. Consequently, as-prepared NPC/CeVO4 material could be a promising material for electrochemical supercapacitor and dye degradation of the tartrazine organic pollutant.

An Eco-Friendly Approach for the Synthesis of Ni/NiO/g-C3N4 Nanocomposite Using Cleome Gynandra Leaf Extract for Biomedical and Photocatalytic Applications

The (Ni/NiO)[Formula: see text]/g-C3N4 nanocomposite was green synthesized using Cleome gynandra via sol–gel method. The photocatalytic dye decomposition, antioxidant and antidiabetic activities of the nanocomposite were studied and compared with those of (Ni/NiO)[Formula: see text] and g-C3N4. The nanocomposite exhibited enhanced photocatalytic efficiency of 97% compared to (Ni/NiO)[Formula: see text] (63%) and g-C3N4 (80%) due to the synergistic effect between both the composite partners. The nanocomposite, (Ni/NiO)[Formula: see text]/g-C3N4 showed notable antioxidant activity in DPPH (IC[Formula: see text] of [Formula: see text][Formula: see text][Formula: see text]g/mL with 87.06% of inhibition at 500[Formula: see text][Formula: see text]g/mL) and ABTS (IC[Formula: see text] of [Formula: see text][Formula: see text][Formula: see text]g/mL with 88.40 % of inhibition at 500[Formula: see text][Formula: see text]g/mL) radical scavenging assays. The green synthesized nanocomposite also exhibited significant antidiabetic activity in [Formula: see text]-amylase and [Formula: see text]-glucosidase enzyme inhibition assays with the IC[Formula: see text] of [Formula: see text][Formula: see text][Formula: see text]g/mL and [Formula: see text][Formula: see text][Formula: see text]g/mL, respectively. The XRD and SEM analyses confirmed the nanocomposite formation of (Ni/NiO)[Formula: see text]/g-C3N4. The results showed that the green synthesized (Ni/NiO)[Formula: see text]/g-C3N4 has desirable dye degradation, antidiabetic and antioxidant properties. This paper presents the results of the remarkable photocatalytic dye decomposition, antidiabetic and antioxidant properties of the nanocomposite (Ni/NiO)[Formula: see text]/g-C3N4 synthesized via an eco-friendly greeny way using Cleome gynandra leaf extract which may be the first report of this kind utilizing this plant.

Self-Assembly Regulated Photocatalysis of Porphyrin-TiO2 Nanocomposites.

Photoactive artificial nanocatalysts that mimic natural photoenergy systems can yield clean and renewable energy. However, their poor photoabsorption capability and disfavored photogenic electron-hole recombination hinder their production. Herein, we designed two nanocatalysts with various microstructures by combining the tailored self-assembly of the meso-tetra(p-hydroxyphenyl) porphine photosensitizer with the growth of titanium dioxide (TiO2). The porphyrin photoabsorption antenna efficiently extended the absorption range of TiO2 in the visible region, while anatase TiO2 promoted the efficient electron-hole separation of porphyrin. The photo-induced electrons were transferred to the surface of the Pt co-catalyst for the generation of hydrogen via water splitting, and the hole was utilized for the decomposition of methyl orange dye. The hybrid structure showed greatly increased photocatalytic performance compared to the core@shell structure due to massive active sites and increased photo-generated electron output. This controlled assembly regulation provides a new approach for the fabrication of advanced, structure-dependent photocatalysts.

Luminescent TiO2 nanoparticles synthesized from Mollugo Oppositifolia and Trianthema Portulacastrum for dye degradation, antimicrobial and antioxidant properties.

In modern times, nanoparticles have materialized as indispensable things in contemporary medicine, with a variety of uses in clinical, drug and gene conveyance. In the present study, TiO2 nanoparticles (NPs) prepared from the leaf extracts of Mollugooppositifolia and Trianthema portulacastrum were compared with the chemical TiO2-NPs for antibacterial and antioxidant activities and environment-friendly nature through various tools like the UV-visible, X-ray diffraction with the aid of other analytical techniques like HR-TEM, Fourier transform infrared (FT-IR) and photoluminescence spectroscopic techniques. The morphology of green TiO2-NPs is found to be spherical, which is supported by HR-TEM images. FT-IR analyses and X-ray diffraction data ensure that the polycrystalline characters of TiO2-NPs alike to the presence of metal oxide. TiO2-NPs showed a possible photocatalytic activity for the ruin of acid black 1 dye after disclosure to sunlight. The chemical and green methods of TiO2-NPs have acid black 1 dye decomposition rates of 86.66% and 94.33%, respectively. The synthesized TiO2-NPs are also assessed for antimicrobial and antioxidant activities. Green TiO2-NPs exhibit antibacterial activity against Pseudomonas aeruginosa (17 + 0.56 mm) and Staphylococcus aureus (16 + 0.24 mm) at concentrations as low as 100 μL. The green TiO2-NPs showed high inhibition of DPPH I radical (50 μg/m) at 95.17 ± 21. Therefore, TiO2-NPs represent eco-friendly properties that aid in the degradation of dyes due to their antioxidant activity.

Green Preparation of Stachys Eudenia-Derived Carbon Quantum Dots and Their Photocatalytic Applications

In this present work, the composites were obtained from carbon quantum dots and TiOf via green synthesis and the photoactivities of these composite structures were investigated under ultraviolet light. Carbon quantum dot was obtained from Stachys euadenia which is an endemic plant found only in southern Türkiye. Carbon quantum dot-TiO2 nanocomposites were fabricated via facile hydrothermal approach which is an easy and effectual method to obtaining of environmentally friendly, low cost and well crystallized nanoparticles. The structural and morphological characteristics of these nanocomposites were investigated by X-ray diffraction, tunneling electron microscopy and scanning electron microscopy. Also, optical analyses of carbon quantum dots were carried out by absorbance and fluorescence spectroscopy. Photocatalytic activity of TiO2 and carbon quantum dot-TiO2 nanocomposites were investigated under ultraviolet light illumination with the decomposition of methylene blue dye. Carbon quantum dot-TiO2 nanocomposites show a better activity than TiO2.