Evaluation Of Photocatalytic Activity Research Articles

Green Synthesis, Characterization, and Evaluation of Photocatalytic and Antibacterial Activities of Co3O4-ZnO Nanocomposites Using Calpurnia aurea Leaf Extract.

The green synthesis of transition metal oxide nanocomposites using plant extracts is a new and effective method that avoids the involvement of hazardous chemicals. Nondegradable organic pollutants and antibiotic drug resistance have become serious public health issues worldwide. Hence, the main objective of this study is to synthesize Co3O4-ZnO nanocomposites using Calpurnia aurea leaf extract and evaluate its photocatalytic and antibacterial activities. The green synthesized particles were characterized using UV-vis spectra, Fourier transform infrared spectroscopy, X-ray diffraction techniques, and scanning electron microscopy combined with energy-dispersive X-ray studies. The synthesized particles were found to be crystalline in nature with average crystallite sizes of 23.82, 14.79, 15.99, 16.46, and 21.73 nm. Scanning electron microscopy shows the spherical morphology of Co3O4-ZnO NCs, and energy-dispersive X-ray analysis confirms the formation of highly pure ZnO NPs and Co3O4-ZnO NCs. The photocatalytic activity was performed under natural sunlight using malachite green as an organic dye pollutant. The green synthesized ZnO NPs, Co3O4 NPs, 1:4, 1:3, and 1:2 Co3O4-ZnO NCs showed high degradation efficiency after 60 min of irradiation. The synthetic material showed good potential against Staphylococcus aureus and Escherichia coli, with the highest growth inhibition recorded by 1:2 Co3O4-ZnO NCs. The kinetics study of the photocatalytic degradation was confirmed as pseudo first order, and the possible mechanisms for both photocatalytic and antibacterial activities were clearly determined.

Green synthesis of silver nanoparticles using Solanum sisymbriifolium leaf extract: Characterization and evaluation of antioxidant, antibacterial and photocatalytic degradation activities

The present study conveyed an in-situ synthesis of silver nanoparticles (Ss-AgNPs) using Solanum sisymbriifolium aqueous leaf extract (SsLE) and their biological activities for the first time. The qualitative and quantitative analysis of SsLE imparted significant amounts of reducing entities/ secondary metabolites. A surface plasmon resonance peak at ∼430 nm of UV–visible spectrum evidenced the formation of Ss-AgNPs. The average particle size of the Ss-AgNPs was found to be 29.87 nm through particle size analyzer. Further, FE-SEM, HR-TEM and XRD analysis verified the spherical shape and high degree of crystallinity with face-centred cubic structure of Ss-AgNPs. The EDX, elemental mapping and FTIR spectral studies, confirmed that various phytochemicals/ metabolites of S. sisymbriifolium leaf extract participated in bio-reduction process and capping of Ss-AgNPs, which might be accountable for the antioxidant activities. Moreover, SsLE and Ss-AgNPs were found to be a rich source of antioxidants and exhibited effective DPPH, H2O2, ṄO scavenging activities along with Ferric ion reducing antioxidant power. The synthesized Ss-AgNPs showed significant antibacterial activity against gram-positive and gram-negative bacteria. In addition to this, Ss-AgNPs supported the degradation of methylene blue (a cationic dye), by performing as a strong photocatalyst under UV and solar irradiations.

Cobalt(II) phenylphenoxides as effective photocatalyst in the degradation of some organic dyes

Removal of toxic dyes by physical, biological and chemical methods have been carried out extensively, of which photochemical degradation, by coordination complexes in particular, has been found to be an effective treatment method owing to the use of natural sunlight as source of energy, resulting in no sludge formation along with the release of less toxic substances in the environment. In this study, synthesis and evaluation of photocatalytic activity of new cobalt(II) phenylphenoxides, 1–4, against some organic dyes viz. Malachite green, methyl orange, crystal violet, methylene blue and fuchsin basic have been studied. The complexes were characterized by physicochemical, 1H NMR, FTIR, high resolution mass spectra (HRMS), powder X-ray diffraction (PXRD) and electrochemical techniques. An attempt has been made to study the effect of varying experimental conditions like concentration of catalyst, nature of ligand, presence of initiator, on the degradation of dyes. Results have shown that the rate of degradation increases with increase in the concentration of catalyst in the presence of environment friendly initiator, hydrogen peroxide. Furthermore, the complexes were found to be more photo-catalytically active towards degradation of malachite green and methyl orange showing degradation of 89.7 % and 95 %, respectively, in the presence of initiator. The photocatalytic degradation of the dyes displayed pseudo first-order kinetics wherein the physical concept of dye degradation i.e. physiosorption governed the adsorption rate of particles onto the adsorbent. The complexes were found to act as effective photocatalyst as well as strong oxidant generator, HO·, carried out by photochemical decomposition of H2O2 under the effect of sunlight. Scavenging studies unveiled the active involvement of hydroxyl radicals (HO·) and electron vacancies (h+) in facilitating the degradation process. Notably, the complexes exhibited remarkable reusability, enduring up to 6 repeat cycles for methyl orange and 5 cycles for malachite green with significant degradation percentages which have revealed their potential role in the degradation of these dyes.

Green fabrication of titanium dioxide nanoparticles via Syzygium cumini leaves extract: characterizations, photocatalytic activity and nematicidal evaluation

ABSTRACT The most significant plant parasitic nematode in terms of economic impact is root-knot nematode (Meloidogyne incognita), which severely harms essential crops used for agriculture. This study investigated green fabrication of titanium dioxide nanoparticles (TiO2 NPs) utilizing Syzygium cumini (SC) leaf extract and evaluated its nematotoxic activity against M. incognita in vitro and in pots. During experiments, second-stage juveniles (J2s) and egg masses of M. incognita were treated with different concentrations (125, 250, 375 and 500 ppm) of SC-TiO2 NPs. After 48 h and five days of exposure, respectively, lowest J2s mortality and per cent inhibition in egg hatching was discovered at 125 ppm, and highest J2s mortality and maximum per cent inhibition in egg hatching determined at 500 ppm. The treatment of SC TiO2 NPs considerably reduced M. incognita infection and enhanced carrot plants' growth and physiological characteristics. The characterization of green synthesized SC-TiO2 NPs made by X-ray diffraction, Photoluminescence, FTIR, SEM, UV-Visible Diffuse Reflectance Spectrophotometer, TEM, and photocatalytic activity also examined. In conclusion, it can be said that SC-TiO2 NPs possess nematode-toxic potential against M. incognita and are used as substitutes for high-risk chemical nematicides without causing any phytotoxicity.

Self-nitrogen-doped hierarchical porous carbon spheres as metal-free catalyst for efficient photocatalytic CO2 reduction

It is rather important to develop an efficient, stable and economical photocatalyst for solar-driven CO2 reduction. Herein, N-doped hierarchical porous carbon spheres (NPCS-F6) with metal-like activity is synthesized using acrylamide and F127 as nitrogen source and soft template, and the effective synergy between nitrogen-containing species and hierarchical pore structure makes the samples exhibit excellent CO2 reduction properties. XPS characterization illustrates that the introduced pyridine nitrogen and pyrrole nitrogen groups contribute to the increase of CO2 reduction sites on the surface of the material. N2 adsorption analysis verifies the existence of hierarchical pore structures in which micropores facilitate the exposure of more adsorption active sites, while mesopores and macropores can be used as transfer channels to connect the internal micropores and reduce the molecular diffusion resistance to improve CO2 adsorption performance. In addition, the pore structure of the samples prepared with P123 and CTAB as templates is mainly microporous, whereas carbon spheres with hierarchical pores coexisting are obtained with F127 as template. The evaluation of photocatalytic CO2 reduction activity shows that the CO yield of NPCS-F6 could reach 17.56 μmol·g−1 for 8 h, which is 1.17 times, 1.08 times and 1.07 times of the original NCS-8 (15.05 μmol·g−1), NPCS-P6 (P123 as soft template, 16.25 μmol·g−1) and NPCS-C1 (CATB as soft template, 16.39 μmol·g−1), respectively. Comprehensive characterization results are analyzed to propose a possible mechanism for photocatalytic CO2 reduction, in which photogenerated electron-hole pairs are generated inside the material under light conditions, and the photogenerated electrons are transferred to the N-6/N-5 active sites through the electron transfer channel N-Q to react with CO2 molecules adsorbed on the surface to be reduced to CO. Finally, our results provide a favorable and feasible strategy to synthesize metal-free photocatalysts for high-efficiency CO2 adsorption and targeted reduction of CO2 to CO.

A novel green synthesis of CuFe2O4 Nanoparticles from Cissus rotundifolia for photocatalytic and antimicrobial activity evaluation

This paper reports a novel green fabrication of copper ferrite (CuFe2O4) nanoparticles (NPs) from Cissus rotundifolia plant extract. The NPs were characterized by different spectroscopic techniques.The Fourier transform infrared (FT-IR) spectrum exhibited intrinsic stretching at the tetrahedral position of Fe–O at 591 cm−1 and the octahedral stretching of Cu–O at 402 cm−1 respectively. The fine diffraction pattern in the X-Ray diffraction analysis (XRD) showed the formation of well-crystalline NPs. The mean crystallite size of the NPs was calculated to be 17.33 nm. The High-resolution Transmission Electron Microscopic (TEM) analysis showed roughly spherical shape and irregular morphology of the NPs. The Zeta potential was calculated to be −29.7±0.3 mV, indicating a negative charge over the CuFe2O4 NPs. The formation of spinel ferrite was confirmed from the characterization data. The photocatalytic activity of the CuFe2O4 NPs was examined against the methylene blue (MB) dye, showing 82% degradation under UV–Visible light. The reusability experiment showed that the catalytic activity was not much decreased even till the 4th cycle. The antibacterial activity of the synthesized CuFe2O4 NPs was tested against Bacillus subtilis, Staphylococcus aureus, Bacilus pumilis, Escherichia coli, Pseudomonas aeruginosa, and Salmonella abony through the Agar well diffusion method. A zone of inhibition of 12±0.2, and 11±0.4 mm was obtained against Bacillus subtilis and Bacillus pumilis, whereas against E. coli, P. aeruginosa and S. abony it was found to be 14±0.4, 18±0.3, and 12±0.2 mm respectively at 75 mg/mL dose, showing appreciable antibacterial activity.

Cadmium oxide nanoparticles doped with nickel and silver: Photocatalytic activity for environmental remediation

In this work, we used a co-precipitation approach to create CdO nanoparticles that were co-doped with nickel (Ni) and silver (Ag). X-ray diffraction (XRD) and field emission scanning electron microscopy (FESEM) were employed to assess the structural attributes of the nanoparticles that were synthesized. Co-doping with Ni and Ag resulted in a steady rise in nanoparticle crystallite size, increasing from 20.97 nm to 32.16 nm. Following the co-doping procedure, FESEM pictures demonstrated a morphological shift from tiny, rock-like formations in pure CdO to bigger rock-like structures. Energy-dispersive X-ray spectroscopy (EDX) was utilised to explore the compositional characteristics of Ni and Ag-doped CdO nanoparticles. The existence of particles’ agglomerations was observed, which may have limited the real surface area available for gas adsorption and resulted in smaller apparent pore sizes in the Brunauer-Emmett-Teller (BET) investigation. Diffused Reflectance Spectroscopy (DRS) revealed a decline in the band gap from 2.45eV to 2.30eV, which was most likely caused by structural changes caused by cadmium ion replacement or the occupancy of interstitial spaces within the lattice by nickel and silver ions. The chemical and electronic states of the atoms were assessed using X-ray photoelectron spectroscopy (XPS), which examined the formation of defects in the form of oxygen vacancies, which contributed to accelerated photocatalytic performance. The deterioration of Crystal Violet (CV) dye during sunlight exposure utilising co-doped CdO nanoparticles vs pristine CdO is being evaluated in the evaluation of photocatalytic activity. Notably, co-doped nanoparticles improved photocatalytic activity significantly, with CV degradation reaching up to 95 % within 180 min of exposure. The potential of Ni and Ag impregnated CdO nanoparticles as effective photocatalysts for environmental remediation applications is highlighted in this study.

Evaluation of photocatalytic activity of Cu3(PO4)2/MgO nanocomposite for the efficient removal of amaranth dye under solar light irradiation

The amaranth dye was removed using photocatalysis on a Cu3(PO4)2/MgO nanocomposite synthesized by co-precipitation method. The crystalline component and the nanostructure of the samples were analyzed by XRD, FTIR, UV–vis-DRS, SEM, EDS, HR-TEM and EIS confirming the successful formation of the nanocomposite. In powder XRD, the average crystallite size is found to be ∼ 26–37 nm. Electrochemical impedance spectroscopy, Nyquist plots represents the charge-transfer resistance at contact interface and the arc diameter of Cu3(PO4)2/MgO is much smaller than that of pure MgO and Thermo gravimetric analysis (TGA), from TGA curve the weight-loss of Cu3(PO4)2 and Cu3(PO4)2/MgO nanocomposite was calculated as 14.18 % and 18.16 % which gives the more contribution to the large enhancement of photocatalytic activity. The photocatalytic degradation efficiency of Cu3(PO4)2/MgO nanocomposite (0.1 g/L, 10 μM and 150 min) was investigated under natural direct solar light irradiation against the dyes. The rate of degradation of amaranth with Cu3(PO4)2/MgO followed pseudo–first order kinetics in the dye concentration. Degradation efficiency (99 %) and degradation rates of amaranth were increases with increasing Cu3(PO4)2/MgO concentration. Generally, this research work advances the possible utilization of Cu3(PO4)2/MgO as an efficient catalyst for taking away of dye from aqueous solution and improvement the catalyst to be used for a numerous cycles. The Cu3(PO4)2/MgO nanocomposites showed good activity against bacteria of Staphylococcus aureus, Staphylococcus pyogenes and Klebsilla pneumoniae.

Spray Coated of ZnO Particles on ePA Nylon-Carbon Fiber Substrate and Its Photocatalytic Activity Evaluation

This work studies a simple deposition of ZnO particles on the ePA Nylon–Carbon Fiber substrate by sol-gel-spray-coating technique. The ZnO films were deposited on the substrate with deposition parameters such as suspension concentration, nozzle-to-substrate distance, nozzle size, coats, pump pressure, and deposition temperature. The ZnO gel suspension concentrations were varied (ZnO-0.06g/ml; ZnO-0.03g/ml), and the post-heated treatment was carried out at 120°C in vacuum condition. The temperature at 45°C during spray coating deposition was also applied to ZnO with the concentration of 0.03g/ml, which was noted as ZnO-0.03 TS. The films were characterized by X-ray diffraction (XRD), Scanning Electron Microscopy/Energy Dispersive X-ray Spectroscopy (SEM/EDS), and Contact Angle (CA) to determine the structure, morphology, and hydrophilicity. The XRD pattern revealed that all samples have a hexagonal wurtzite structure. The SEM results showed that ZnO-0.06 relatively shows a dense surface, while ZnO-0.03 and ZnO-0.03 TS have a porous surface. The atomic ratio (Zn:O) revealed from the EDS measurement of the films was stoichiometric. The CA measurement showed that the film surfaces are hydrophilic. In addition, the photocatalytic activity was evaluated by the degradation of 2 mg/L methylene blue irradiated by sunlight for 180 mins—the photodegradation efficiencies were 88.37 %, 90.22 %, and 89,47 %, respectively.

AG2O Nanoparticle and Its Composite with Coordination Polymers of Cu: Synthesis, Characterisation and Photocatalytic Activity

In this study, we report the synthesis, characterisation, and photocatalytic activity evaluation of Ag2O nanoparticles (NPs) and their composite, Ag2O/Cu-CP, with coordination polymers (CPs) of Cu. Ag2O NPs were synthesised using the coprecipitation method. The composite was prepared via the sonication method. FTIR and XRD patterns revealed the formation of the nanoparticles and composite. Photocatalytic activity of the NPs and Composite was performed under solar irradiation for Methylene Blue (MB) as a dye. The photocatalytic degradation efficiency was monitored for concentration decay over time using UV-Vis. Spectrophotometer. The synthesised Ag2O/Cu-Cp composite showed a degradation efficiency of 97.59%, whereas Ag2O NPs showed an efficiency of 82.23%. The composite exhibited 1.18 times higher activity than Ag2O NPs. The band gap plays a crucial role in enhancing activity. The incorporation of Cu-Cp with Ag2O NPs reduced the band gap to an optimum level for radical formation. So, this kind of composite could be widely used in the effluent treatment of industry for a green environment.Keywords: Ag2O nanoparticles, composite, powder-XRD, dye degradation, photocatalytic activity, UV-vis spectroscopy

Bio-extract-mediated microwave-assisted synthesis of Cr2O3 nanoparticles: Characterization, antibacterial, antioxidant, and photocatalytic activity evaluation

Bio-extract-mediated microwave-assisted synthesis of Cr2O3 nanoparticles: Characterization, antibacterial, antioxidant, and photocatalytic activity evaluation

Evaluation of photocatalytic activity of heterojunctions between bismuth oxyhalides and hematite in the degradation of organic compounds in liquid phases under visible light

Photocatalysts were synthesized by constructing p-n type heterojunctions between bismuth oxyhalides BiOX (X = I or Br) and hematite (α-Fe2O3) for enhanced visible light photodegradation of pollutants in aqueous medium. BiOX, in this text called precursors, were synthesized using a modified solvothermal method and by coprecipitation. Hematite was added using hydrothermal treatment. Herein the materials prepared using precursors and hematite are being called catalysts. All materials were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), diffuse reflectance spectroscopy (DRS) and adsorption assays with N2. The characterization of BiOX revealed that the solvothermal methods synthesized precursors with greater surface area and structural uniformity than those obtained by coprecipitation. The BiOI precursors, had observed reaction rate constant, kap, values for rhodamine between 0.0054 and 0.0167 min−1. The BiOBr precursors provided values between 0.1016, and 0.0515 min−1. In order to synthesizing the catalysts, an experimental planning was carried out. It showed that Fe/Bi ratio was the variable with the greatest impact on activity, followed by temperature. The BiOI catalysts had kap maximum values for rhodamine between 0.0419, and 0.0213 min−1, while BiOBr catalysts between 0.1144 and 0.1082 min−1. BiOI and BiOBr catalysts provided kap at least 2.0 and 1.12 times greater than their precursors, respectively. Also, successfully degraded phenol, confirming photocatalytic activity of the catalyst surface.

Synthesis and characterization of enhanced visible light-driven C-doped ZnO-2D GO/g-C3N4 heterojunction photocatalyst

Well-designed 2D graphene oxide-modified polymeric graphitic carbon nitride composite nanosheets (GO/g-C3N4) as desirable sensitizers and catalytic substrates for optimising the visible light-driven photocatalytic performance of ZnO-based photocatalysts have been investigated. Herein, 2D GO/g-C3N4 composite nanosheets are first developed by ultrasonic and hydrothermal methods, and then coupled with ZnO nanoparticles to prepare a series of ternary GO/g-C3N4-ZnO heterojunction composites with vary GO loading concentrations. Characterization of the photocatalysts was carried out by SEM, TEM, XPS, XRD, DRS, photoluminescence (PL) spectroscopy; evaluation of the visible light photocatalytic activity was performed by degrading an aqueous methylene blue (MB) solution. XPS studies showed that the formation of a ZnC bond in 15 % GO/g-C3N4-ZnO is due to the replacement of oxygen by carbon, indicating the construction of a hybrid heterojunction composed of C-doped ZnO and visible light sensitive GO/g-C3N4 composite nanosheets. The photodegradation performance of 15 % GO/g-C3N4-ZnO is 5.3, 2.9, and 2.2 times higher than that of pure ZnO, g-C3N4, and g-C3N4-ZnO, respectively. Due to the increase of GO loading in GO/g-C3N4 composite nanosheets, some characteristics of efficient visible light photocatalysis, such as a wider light absorption range, fluorescence quenching in the PL spectrum, excellent optical response in photocurrent measurement, and good stability，were confirmed and can be attributed to the electronic interaction between heterostructures and the effective transfer of photogenerated electrons in these ternary nanocomposites. This work may provide a new promising pathway for the construction of easily prepared 2D GO/g-C3N4 hybrid-modified nanocomposites, which is a hopeful material for wastewater control.

Synthesization and Photocatalytic Activity Evaluation of Float-Type g-C3N4 Microtubes

Float-type g-C3N4 microtubes were created by hydrothermal method and calcination using g-C3N4. Substances after hydrothermal synthesis and float-type g-C3N4 microtubes were investigated by XRD and SEM. The photocatalytic activity of float-type g-C3N4 microtubes was evaluated by methylene blue decomposition. According to these results, the substance, such as a needle, was found to have the same crystal structure as g-C3N4. In addition, it was confirmed that the needle-like substance was hollow inside, according to the SEM result. This substance can float on water. Therefore, Float type g-C3N4 microtubes can receive more light, and the decomposition rate has increased compared to g-C3N4.

Enhanced photocatalytic activity and antiviral evaluation of CuO@Fe2O3 NC for amoxicillin degradation and SARS-CoV-2 treatment.

Copper oxide nanoparticles (CuO NPs) and CuO NPs decorated with hematite (Fe2O3) nanocomposites (CuO@Fe2O3 NC) were biosynthesized by a green method using Portulaca oleracea leaves extract. The NC were characterized using various techniques, including X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), and UV-Vis spectroscopy. The results showed that the synthesized CuO and CuO@Fe2O3 NC were crystalline with a monoclinic crystal structure and contained functional groups responsible for catalytic activity. The size of the nanocomposites ranged from 39.5 to 45.9 nm, and they exhibited a variety of agglomerated or aggregated shapes. The CuO@Fe2O3 NC showed improved photocatalytic activity for the degradation of antibiotics in water and wastewater and promising antiviral activity against SARS-CoV-2, indicating its potential for use in disinfection applications. The study investigated the impact of irradiation time on the photocatalytic degradation of Amoxicillin and found that increasing the irradiation time led to a higher degradation rate. The band gap energy (Eg) for pure CuO NPs was around 2.4 eV and dropped to 1.6 eV with CuO@Fe2O3 NC. In summary, the CuO@Fe2O3 NC has the potential to be an efficient photocatalyst and promising antiviral agent for environmental remediation. The CuO@Fe2O3 nanocomposites have been found to possess a high degree of efficacy in inactivating SARS-CoV-2 infectivity. The results of the study indicate that the nanocomposites exhibit potent anti-viral properties and hold significant potential for use in mitigating the spread of the virus.

Phyto-synthesis of Pure and Mn Doped SnO2 Nanoparticles: Evaluation of Antimicrobial, Antioxidant and Photocatalytic Activities

Phyto-synthesis of Pure and Mn Doped SnO2 Nanoparticles: Evaluation of Antimicrobial, Antioxidant and Photocatalytic Activities

Seed-Assisted Hydrothermal Synthesis of Radial TiO2 Homomesocrystals and the Application as a Support for Plasmonic Photocatalysts

Radial homomesocrystals consisting of rutile TiO2 nanorods (NRs) were hydrothermally synthesized with TiO2 seed nanocrystals (rad-TiO2 HOMCs). The addition of the seeds greatly reduces the synthesis temperature and time. Transmission electron microscopic analyses show that the formation of rad-TiO2 HOMCs proceeds via epitaxial generation of nanoneedle-like nuclei on the seed surface, the growth of TiO2 NRs in the [001] direction, and their radial self-assembling with the transformation of amorphous to rutile TiO2. Au nanoparticles (NPs) with similar sizes and amounts were highly dispersed on rad-TiO2 HOMCs (Au/rad-TiO2 HOMCs) and two kinds of commercially available rutile TiO2 NPs (Au/TiO2 NPs) by the deposition precipitation method. As a test reaction for the evaluation of the plasmonic photocatalytic activity, degradation of 2-naphthol was examined by using it as a model water pollutant under illumination of weak visible light (λex > 430 nm, AM-1.5, 12.5 mW cm–2). In the Au/TiO2 systems, a positive correlation holds between the photocatalytic activity and the faceting probability of Au NPs on TiO2. The photocatalytic activity of Au/rad-TiO2 HOMCs much higher than those of Au/TiO2 NPs can stem from the plasmonic hot spot formation near the corners and edges of the faceted Au NPs and effective charge separation characteristics of the Au/rad-TiO2 HOMC system.

Evaluation of Photocatalytic Activity and Electrochemical Properties of Hematite Nanoparticles

The symmetric nano morphologies, asymmetric electronic structures, and as well as the heterojunctions of the developed photocatalytic systems perform a vital role in promoting light absorption, separation of electron and hole pairs and charge carrier transport to the surface when exposed to near-infrared (NIR) light. In this present work, we synthesized hematite (α-Fe2O3) nanoparticles (NPs) by a facile hydrothermal method and studied their structural, optical, and photocatalytic properties. Powder X-ray diffraction (XRD) confirmed the rhombohedral phase of the α-Fe2O3 NPs, and Fourier transform infrared spectroscopy (FT-IR) was used to investigate symmetric and asymmetric stretching vibrations of the functional groups on the surface of the catalysts. The optical bandgap energy was estimated to be 2.25 eV using UV-Vis diffuse reflectance spectroscopy (UV-Vis DRS) and scanning electron microscopy (SEM) images indicated sphere like morphology. The oxidation and reduction properties of α-Fe2O3 NPs were analyzed by cyclic voltammetry (CV). The α-Fe2O3 NPs were utilized for the degradation of methylene blue (MB) dye under natural sunlight. The experimental results demonstrate that the degradation efficiency was achieved at 33% in 2 h, and the pseudo-first-order rate constant was calculated to be 0.0033 min−1.

G-C3N4/Fe3O4 composites synthesized via solid-state reaction and photocatalytic activity evaluation of methyl blue degradation under visible light irradiation

This study applied the solid-state reaction technique to synthesize g-C3N4, Fe3O4, and g-C3N4/Fe3O4composites in various ratios. XRD confirmed the formation of g-C3N4, Fe3O4, and a g-C3N4/Fe3O4heterostructure. SEM confirmed the rod-shaped structure of Fe2O3and the layered-like fabrication of g-C3N4. The Egof g-C3N4/Fe3O4was approximately 1.9 eV, making it a beneficial composite material for visible response in photocatalysis activity, which was confirmed by UV-Vis spectroscopy. Dielectrics were used to study ferrite nanoparticles and provide information on the mechanism of conductivity in the parts of the dielectric that responded to an applied alternating electric field. In polycrystalline ceramics, the resistive and capacitive grains, contributions, electrode specimen interfaces, and grain boundaries may all be distinguished using impedance analysis, a crucial tool for the study of complicated electrical performance. The g-C3N4/Fe3O4composite material showed high photocatalytic activity against methylene blue (MB) dye.

PEG functionalized ZnO nanoparticles by fusion of precipitation-cum-hydrothermal method with enhanced photocatalytic activity

In this study, polyethylene glycol (PEG)-aided zinc oxide (ZnO) nanoparticles (NPs) have been synthesized by fusion of precipitation-cum-hydrothermal method. The PEG/ZnO NPs were investigated by x-ray diffraction (XRD), Fourier-transform infrared (FTIR) transformation, UV-visible field emission scanning electron microscope (FESEM), energy dispersive x-ray, high resolution transmission electron microscope (HRTEM), and RAMAN techniques. XRD analysis confirms the formation of the wurtzite phase with a crystallite size of 8 nm of synthesized PEG/ZnO. While FESEM and HRTEM investigations reveal the formation of distinct structural forms, FTIR investigations show interactions between PEG and ZnO. High crystallinity of PEG/ZnO is observed in the selected area electron diffraction pattern. The Brunauer–Emmett–Teller (BET) study revealed that ZnO NPs have a mesoporous structure with a significant specific surface area of 42 m2 g−1. The evaluation of photocatalytic activity of PEG/ZnO-based photocatalyst was carried out via the degradation of typical azo dye (industrial methylene blue (MB) dye) along with total organic carbon (TOC) analysis. The PEG-ZnO (dose 200 mg l−1) was found to be an efficient photocatalyst for the degradation of MB dye. The degradation reaction exhibits pseudo-first-order kinetics. Additionally, TOC removal was monitored, elucidating almost complete mineralization.