Reflux Condensation Method Research Articles

Efficient triethylamine sensing achieved by in-situ Zn2+ doping regulated Mo-MOFs derived MoO3/ZnMoO4 heterostructures

Triethylamine (TEA) poses severe safety hazards to industrial production and human health. To accurately detect TEA concentrations and rapidly warn of leakage, a simple reflux condensation method was deployed to successfully incorporate Zn2+ in situ into Mo-MOFs precursor in a green, safe, and time-efficient synthesis condition. Subsequently, through calcination, MoO3/ZnMoO4-X (MMZ-X) were prepared, which exhibited an increased number of defects and enriched porosity, facilitating the access and interaction of TEA with adsorption sites. Simultaneously, rationally built in situ MoO3/ZnMoO4 heterostructures accelerated carrier migration and induced a drastic resistive change. MMZ-2 demonstrated outstanding TEA sensing performance, exhibiting extremely high sensitivity (R = 572.3, 100 ppm), along with superior selectivity, repeatability and stability, rapid response and recovery times, and a low detection limit. Moreover, the key intrinsic parameters of the heterostructure on the atomic scale were determined by density functional theory (DFT) calculations, providing a detailed elucidation of the sensing enhancement mechanism of the MoO3/ZnMoO4 heterostructure. The simple and efficient synthesis method and the related mechanistic analysis pave a new path for designing high-performance TEA gas sensors with practical applications.

Utilization of copper chromite-reduced graphene oxide nanocomposite for the wastewater remediation and effective supercapacitive performance

This article has detailed the growth of virgin copper chromite nanoparticles (CuCr2O4 NPs) and reduced graphene oxide sheet (rGO)-based CuCr2O4 nanocomposite through the process of reflux condensation method and calcination process. When exposed to visible light, these two synthesized nanomaterials exhibit enhanced photocatalytic activity which helps in the degradation of organic dyes such as methylene blue. Numerous characterization methods, including FTIR, UV–visible analysis, and XRD, verify the creation of these nanomaterials. The CuCr2O4-rGO nanocomposite's semiconductor nature is confirmed by the band gap analysis using Tauc's formula. The CuCr2O4 NPs grown on the rGO surface have a dimension of 6 nm, according to the TEM study and particle distribution graph. To find the reason for the enhanced photo-activity, we have proposed a photocatalytic mechanism which is supported by photoluminescence result. Recyclability in five more cycles is used to measure the stability of the nanocomposite, and it is found that photocatalytic efficiency does not significantly decline up to five cycles. When exploring the CuCr2O4-rGO nanocomposite as a material for supercapacitor electrodes, it showcased a remarkable specific capacity of 681.43 F/g at 0.5 A g−1. Moreover, the CuCr2O4-rGO nanocomposite electrode displayed a long-term life cycle, retaining 93.8 % of its initial capacity after 1200 cycles, paired with a commendable Coulombic efficiency of 95.31 % and outstanding power and energy density of 1504 W/kg and 23.66 Wh/kg respectively.

Effect of annealing environment on the electrochemical performance of biosynthesized V2O5@C thin films

In the present work, the V2O5 thin films were prepared on flexible stainless steel mesh (FSSM) substrate using Bengal gram bean extract (BGBE) as a medium by reflux condensation method for its use as an electrode for supercapacitor application. The bio-molecules present in BGBE were in-situ converted into carbonaceous material after the annealing process. A systematic study of the influence of the annealing environment was investigated by heating the as-prepared V2O5 thin films in two different annealing atmospheres viz nitrogen and air. The annealing of the as-prepared V2O5 thin films under N2 atmosphere (V2O5-N) produces more carbonaceous material when compared to V2O5 thin films annealed in air atmosphere (V2O5-A). Interestingly, annealing in air atmosphere completely oxidizes the biomass, while annealing in nitrogen leaves traces of carbonaceous matrix in the thin film. This improves the conductivity and electrical properties of the material and its advantage is taken in fabricating supercapacitor devices. The obtained V2O5-N and V2O5-A thin films were characterized using X-ray diffraction (XRD), Scanning Electron Microscopy (SEM), Raman, and X-ray Photoelectron Microscopy (XPS). Moreover, the electrochemical performance of V2O5-N and V2O5-A was investigated. The V2O5-N electrode exhibited a specific capacitance (Csp) of 633.3 F g−1 with an energy density (ED) of 87.9 wh kg−1 at 2 mA cm−2 current density and good cycles stability with capacitive retention of 86.2 % over the 10,000 continuous GCD cycles which is higher than the V2O5-A. A flexible symmetric solid state (SSC) device was assembled using V2O5-N electrodes with PVA-LiClO4 gel electrolyte. The device exhibited a Csp of 82.6 F g−1 with an ED of 22.4 wh kg−1 at 1 mA cm−2 current density. In summary, the V2O5-N demonstrated significantly improved electrochemical performance than the V2O5-A electrode and is supported with the appropriate data.

Economic and binder-free synthesis of NiCo2O4 nanosheets on a Flexible stainless steel mesh as a bifunctional electrode for water splitting

Water as a green source of hydrogen has attracted the attention of researchers considering its potential applications in the energy sector. Thus, developing efficient bifunctional electrocatalysts for water splitting is a potential challenge perceived by researchers exploring the development of sustainable energy technologies. With this motive, the present study focuses on the preparation of the highly active, economic, binder-free, and bifunctional NiCo2O4 nanosheets@ Flexible Stainless Steel Mesh substrate (NCO@FSSM) electrocatalyst via reflux condensation method for the bulk O2 and H2 production. The influence of reflux condensation temperatures (100, 120, 140 °C) on the morphology and electrocatalytic activity is investigated. Electrocatalytic properties for NCO@FSSM synthesized at 120 °C were noted exhibiting smaller overpotentials for oxygen evolution reaction (OER, 310 mV) and hydrogen evolution reaction (HER, 79 mV) at 10 mA cm−2, which were lowest among the previously reported Ni, and Co-based electrodes. Additionally, the scale-up experiments with NCO-120@FSSM film (8 cm X 8 cm) as an anode and FSSM as a cathode and vice-versa, in a specially designed scale-up electrochemical cell revealed steady electrocatalytic performance. The real-time water splitting was studied for 25 h and was noted to produce 7.4 L of (O2) and 11.5 L of hydrogen (H2).

Synthesis of Tio2 photocatalyst with tunable optical properties and exposed facet for textile wastewater treatment

TiO2 semiconductor plays a paramount important as an active photocatalyst mainly due to its photo-induced electron transfer properties. The metastable anatase in particular are widely accepted to have the most photoactive activity in catalytic application as opposed to rutile TiO2. This is majorly due to the significantly lower recombination rate of electron pair possesses by anatase TiO2. Unfortunately, high recombination rate in anatase TiO2 hinders its application as a functional photocatalyst. Therefore, it is crucial to further enhance the photocatalytic activity of anatase TiO2, by modifying its optical properties, morphological properties, and crystal facet. The study aims to provide a benign synthesis method for TiO2 with a co-exposed {001}/{100} anatase TiO2 facet. The synthesis was conducted via one-pot reflux condensation method. A concise evaluation upon the effect of different synthesis heating duration, temperature and doping materials towards the crystal phase, morphology, and photocatalytic performance of TiO2 were conducted. Anatase TiO2 with high percentage of the high-energy {001} facet have the ability to boost the adsorption and photocatalytic performance as opposed to anatase TiO2 dominated with a thermodynamically stable {101} facet. The incorporation of non-metal dopant (HF) acts as surface modifier which leads to the enhancement of {001} facet percentage. This study further evaluates the functionalities of HCl in paving way towards the formation of mid-gap state, hence improving Anatase TiO2 optical properties. The reduction of band gap of the anatase TiO2 can clearly be identified from the shifts in the adsorption band towards higher wavelength. From the findings, it was found that the synergistic effect upon co-doping anatase TiO2 with the two non-metal dopants plays an important role in altering the ratio of exposed facet hence leading towards improving the photocatalytic efficiency of the nanomaterial. To evaluate the photocatalytic performance of the synthesized TiO2, Remazol Brilliant Blue (0.01 g/L) was chosen as the target pollutant. The enhanced photodegradation of co-doped F/Cl-TiO2 was evaluated and it was found that 87.21% and 43.21% of Remazol Brilliant Blue had successfully been degraded within 120 min with irradiation of broad spectrum and blue light (475 nm) respectively. This is mainly attributed to the co-exposed {001}/{100} anatase TiO2 facet presence in the F/Cl-TiO2 sample.

Construction of Well-Defined Two-Dimensional Architectures of Trimetallic Metal-Organic Frameworks for High-Performance Symmetric Supercapacitors.

The high surface-to-volume ratio and extraordinarily large-surface area of two-dimensional (2D) metal-organic framework (MOF) architectures have drawn particular interest for use in supercapacitors. To achieve an excellent electrode material for supercapacitors, well-defined 2D nanostructures of novel trimetallic MOFs were developed for supercapacitor applications. Multivariate MOFs (terephthalate and trimesate MOF) with distinctive nanobrick and nanoplate-like structures were successfully synthesized using a straightforward one-step reflux condensation method by combining Ni, Co, and Zn metal species in equimolar ratios with two different ligands. Furthermore, the effects of the tricarboxylic and dicarboxylic ligands on cyclic voltammetry, charge-discharge cycling, and electrochemical impedance spectroscopy were studied. The derived terephthalate and trimesate MOFs are supported with stainless-steel mesh and provide a suitable electrolyte environment for rapid faradaic reactions with an elevated specific capacity, excellent rate capability, and exceptional cycling stability. It shows a specific capacitance of 582.8 F g-1, a good energy density of 40.47 W h kg-1, and a power density of 687.5 W kg-1 at 5 mA cm-2 with an excellent cyclic stability of 92.44% for 3000 charge-discharge cycles. A symmetric BDC-MOF//BDC-MOF supercapacitor device shows a specific capacitance of 95.22 F g-1 with low capacitance decay, high energy, and power densities which is used for electronic applications. These brand-new trimetallic MOFs display outstanding electrochemical performance and provide a novel strategy for systematically developing high-efficiency energy storage systems.

Effect of Small Change in Reaction Conditions on the Size of Monoclinic BiVO4 Nanoparticles and their Photocatalytic Abilities

AbstractBiVO4 is an effective material and highly used in different applications. Here, we have synthesized BiVO4 using bismuth nitrate pentahydrate and ammonium metavanadate by simple reflux condensation method without addition of any surfactant. To check the effect on the structure and activity of BiVO4 different ratios of bismuth nitrate pentahydrate to ammonium metavanadate e. g. 1 : 1, 1 : 2 and 2 : 1 were used. Obtained BiVO4 nanomaterial was successfully analysed using various analytical techniques such X‐ray diffraction (XRD), Brunauer–Emmett–Teller (BET), Field emission scanning electron microscopy (FE‐SEM) and X‐ray photoelectron spectroscopy (XPS). The nanoparticles were shown spherical morphology, high porosity and monoclinic scheelite (m) crystalline phase. It was observed that BiVO4 nanoparticles prepared using 1 : 1 ratio have very small size as compared to those prepared using other ratios. Further, the photocatalytic activity of the BiVO4 nanoparticles was assessed by photodegradation of crystal violet dye (CV) under visible light irradiation and found that the particles prepared with 1 : 1 ratio were showing high efficiency of degradation. In addition, prepared nanoparticles have shown good antibacterial properties.

Structural and biological properties of novel Vanadium and Strontium co-doped HAp for tissue engineering applications

The development of novel bioactive materials with improved physical and biological properties is crucial for advancing tissue engineering applications. In this study, we synthesized a Vanadium and Strontium co-doped hydroxyapatite (V–Sr:HAp) nanoparticle intending to enhance the performance of pure HAp. The V–Sr:HAp nanoparticles were synthesized using a microwave-assisted reflux condensation method, and their structural and chemical characteristics were investigated using X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, Raman spectroscopy, and X-ray photoelectron spectroscopy (XPS). The morphology and elemental composition of the nanoparticles were examined through scanning electron microscopy (SEM) and energy-dispersive X-ray analysis (EDX). The XRD analysis confirmed the presence of characteristic peaks of HAp in each sample. SEM images revealed well-connected and highly agglomerated small sphere-like morphology in both pure HAp and V–Sr:HAp nanoparticles. The Vickers hardness test demonstrated the improved mechanical strength in V–Sr:HAp compared to pure HAp. Antibacterial efficacy was evaluated using an agar diffusion test, which showed enhanced antibacterial activity in the co-doped HAp samples against S. aureus and P. aeruginosa. Moreover, the Ca–P deposition rate on the surface of the co-doped HAp samples during biomineralization was higher. Hemolysis assay results have indicated compatibility of both pure HAp and V–Sr:HAp with human blood (<5% lysis). The results of cell viability tests demonstrate that the V and Sr co-doped HAp samples do not exhibit any cytotoxic effects and instead promote cell proliferation. Overall, the incorporation of V and Sr metal ions into HAp presents a promising bio-functional tool for tissue engineering applications, offering improved mechanical and antibacterial properties.

Enhancing photodegradation of Methyl Orange by coupling piezo-phototronic effect and localized surface plasmon resonance

Piezo-potential promoted photocatalysis enables a scalable and high-efficiency dye decomposition by conjugating the photoexcitation and mechanical stimulus. However, its catalytic efficiency is significantly restricted by the limited quantum yield and piezoelectric activity of catalysts. Herein, a heterogeneous CdS-Au composite photocatalyst was synthesized via a facile water bath heating and reflux condensation method for organic pollutants degradation. The synergism between piezo-phototronic effect and localized surface plasmon resonance facilitates photon-generated carrier separation and internal quantum efficiency. The loading of Au nanoparticles remarkably modulates the morphologies, surface defect, effective optronics utilization and photocatalytic activities of CdS nanospheres. A 2.3 folds enhancement in the photodegradation of Methyl Orange (MO) was observed with the optimal 4 mol% Au loading. Furthermore, the impact of frequency and intensity of ultrasonication on the electrochemical impedance and photocatalytic activity was systematically investigated. This work offers a promising approach for harnessing noise or vibration for environmental remediation and opens up a new route for designing and developing high-performance piezo-photocatalyst.

Structure-engineering of core-shell ZnCo2O4@NiO composites for high-performance asymmetric supercapacitors.

The implementation of a structure-designed strategy to construct hierarchical architectures of multicomponent metal oxide-based electrode materials for energy storage devices is in the limelight. Herein, we report NiO nanoflakes impregnated on ZnCo2O4 nanorod arrays as ZnCo2O4@NiO core–shell structures on a flexible stainless-steel mesh substrate, fabricated by a simple, cost-effective and environmentally friendly reflux condensation method. The core–shell structure of ZnCo2O4@NiO is used as an electrode material in a supercapacitor as it provides a high specific surface area (134.79 m2 g−1) offering high electroactive sites for a redox reaction, reduces the electron and ion diffusion path, and promotes an efficient contact between the electroactive material and electrolyte. The binder-free ZnCo2O4@NiO electrode delivers a high specific capacitance of 882 F g−1 at 4 mA cm−2 current density and exhibits remarkable cycling stability (∼85% initial capacitance retention after 5000 charge–discharge cycles at 10 mA cm−2). The asymmetric supercapacitor device ZnCo2O4@NiO//rGO delivered a maximum energy density of 46.66 W h kg−1 at a power density of 800 W kg−1. The device exhibited 90.20% capacitance retention after 4000 cycles. These results indicate that the ZnCo2O4@NiO architecture electrode is a promising functional material for energy storage devices.

Extraction and Isolation of Phenolic compounds from Sweet lime and Evaluation of Anticancer potentiality followed by Molecular docking against Topoisomerase II

The main aim and objective of the present research work was the isolation of some novel bioflavanoids from methanolic extract of peels of sweet lime (MEE-PSWL) and evaluation of in vitro anticancer activity followed by molecular docking against target protein topoisomerase II. The extraction was done by reflux condensation method and preliminary phytochemical screening of MEE-PSWL was carried out for the evaluation of bioactive molecules, the bioflavanoids present in MEE-PSWL was confirmed by spectral analysis such as ESI-MS-MS and FTIR. Molecular docking of isolated compounds was carried out against target protein Topoisomerase II with PDB id 1ZXM by Auto dock program and the best dock pose was selected based on the interaction study analysis. In vitro anticancer activity MEE-PSWL was evaluated by SRB assay toward human colon adenocarcinoma cell line SW620 and the test was carried out at different concentrations. A preliminary screening displayed that the MEE-PSWL was able to inhibit the proliferation of more than 60% of human colon adenocarcinoma SW620 cells. The maximum growth of inhibition was found to be at 125µg/ml (IC50 4.5µg/ml) and the standard drug doxorubicin was found to inhibit the maximum proliferation at concentration 75µg/ml (IC50 3µg/ml).

Synthesis of luminescent Mg-incorporated hydroxyapatite by reflux condensation method: Photoluminescence, in-vitro drug release and kinetic studies

The role of biomaterials in the field of medicine has immense applications because they are engineered to be in close proximity to the biological organ or tissue and thereby healing or replacing the damaged tissues or organs. These biomaterials are of natural and synthetic made of different components to interact with the biological system. They can be tailored in such a way either for therapeutic or diagnostic purposes. The focus of the present study is to prepare nanosized magnesium doped hydroxyapatite (Mg-HAp) using magnesium nitrate as the source of magnesium (Mg). The reflux condensation method was used to synthesize pure HAp and Mg-HAp samples that were subjected to microwave irradiation. XRD studies verify that the integration of Mg into HAp did not bring about any phase changes in HAp. Further, the changes in the lattice parameters of Mg-HAp show that Mg is well incorporated into the HAp lattice. FTIR and Raman spectroscopic investigations show the absence of the hydroxyl group, which adds to the confirmation of Mg substitution in the HAp lattice. Crystallinity and size of the Mg-HAp decreased for microwave irradiated samples compared to as-synthesized samples because of the uniform heating of the sample. The morphology of Mg-HAp samples further indicates that particle size reduces with increasing Mg concentration which was proven by SEM results. Photoluminescence spectra of microwave irradiated Mg-HAp samples exhibit increased intensity for increased Mg concentration because of the blocking of recombination of charge carriers. The self-luminescent property of Mg-HAp particles, which is because of their surface plasmon, can be used in imaging and drug delivery applications.

Preparation and spectral properties of CuSe/ZnSe core-shell nanomaterials

In this research, first, CuSe nanoparticles (NPs) were synthesized by using the reflux condensation method. Then, a ZnSe shell was grown on the CuSe NPs by using a simple, rapid photochemical approach. Synthesized CuSe/ZnSe core-shell NPs were characterized by means of different analyses, such as X-ray diffraction (XRD), energy dispersive X-ray spectroscopy (EDS), X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM), UV-visible (UV-Vis) spectroscopy and photoluminescence (PL) spectroscopy. The XRD analysis of the sample shows the formation of core-shell NPs with the structure of hexagonal CuSe and cubic ZnSe. The core-shell structure of the product has been formed and the size of the synthesized core-shell NPs is about 20–50 nm. The band gap of the CuSe/ZnSe core-shell NPs was higher than that for CuSe or ZnSe in bulk. The fluorescence properties were greatly enhanced by successful growth of the ZnSe shell and decreased with the extension of illumination time.

Heterogeneous WO3/H2O2 system for degradation of Indigo Carmin dye from aqueous solution

In this work, tungsten oxide crystals (WO3), with different sizes and morphologies were prepared using the reflux condensation method. Tungsten oxide crystals were characterized by X-ray diffraction, scanning electron microscopy, Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy. Then, the particles were used as a heterogeneous Fenton-like catalyst in the presence of green oxidant H2O2 for Indigo Carmin (IC) dye degradation. The efficiency of the coupling WO3/H2O2 showed at 600 °C, that it was possible to remove about 90% of the initial color of IC after 120 min in a batch reaction at 65 °C. Moreover, the coupling maintained high activity after four continuous cycles when tungsten oxide particles were recorvered.

Structural, thermal and electro-optical properties of guanidine based Metal-Organic Framework (MOF)

An hybrid metal-organic framework formulated as 3[2(CH6N3)+.Cl4 Mn(II)] has been synthesized by reflux condensation method of reacting guanidinium carbonate with manganese chloride. From synthesized material, good quality of single crystals have been harvested by solvent evaporation technique and characterized by single crystal XRD (SCXRD), DT-TGA analysis, UV–visible spectroscopy and Z-Scan. SCXRD investigation establishes that grown crystal crystallizes in the monoclinic crystal system with space group P 21/c. The crystal structure features strong metal-organic frameworks through Mn-Cl bonds, it limits its coordination for three adjacently connected octahedrons and making a closed metal-chlorine volume. Thermal properties have been examined by differential thermal (DT) and thermogravimetric analysis (TGA). Temperature and frequency-dependent dielectric properties have been investigated by LCR meter. The existence of third order nonlinear optical susceptibility and intensity tunable optical limiting responses have been confirmed by the Z-scan technique.

Hybrid photocatalytic systems comprising a manganese complex anchored on g-C3N4 for efficient visible-light photoreduction of CO2

Inorganic–organic composites are triggering an increasing interest in the photocatalytic reduction of CO2 due to its stability and high efficiency. In this study, the reflux condensation method was used to synthesize 2,2-bipyridine-4,4-bisphosphonic acid tricarbonyl manganese bromide complex (MnP), which was then anchored onto g-C3N4 via a facile self-assembly method. The resulting g-C3N4/MnP composites catalysts exhibited efficient photocatalytic reduction of CO2 under visible light irradiation. Moreover, the yield of CO of g-C3N4/MnP catalyst was 5 times more compared with pure g-C3N4 catalyst. Additionally, the only product of catalytic reduction of CO2 was CO. These results were attributed to that the Mn complex played important role in the photocatalytic reduction of CO2 to CO by the composite catalyst. An integrated “Z-scheme” mechanism was proposed for CO2 reduction using the g-C3N4/MnP system. This hybrid photocatalyst system has good application prospects in the field of photocatalysis owing to its environmental friendliness and strong visible- light absorption.

The favourable synergistic operation of photocatalysis and catalytic oxygen reduction reaction by a novel heterogeneous CoFe2O4-TiO2 nanocomposite

The improved photocatalytic activity of TiO2 with the addition of spinel CoFe2O4 as an effective catalyst for O2 reduction reaction (ORR) is studied and proved in this study. CoFe2O4-TiO2 heterostructure nanoparticles are prepared by a reflux condensation and two-step hydrolysis-hydrothermal method. The addition of trace CoFe2O4 onto TiO2 can improve its affinity to O2, generate a faster transportation of photo-induced carriers, but hardly affect band structure. With an appropriate amount of CoFe2O4 to TiO2, a remarkable acceleration occurs in photocatalytic decolorization of dye wastewater, and the calculated apparent kinetic constant (kapp) of the composite (0.020 min−1) is 2.4 and 5.6 times of pure TiO2 (0.0085 min−1) and CoFe2O4 (0.0036 min−1), respectively. Quenching experiments with different radical scavengers show that O2–∙ is the key oxidative radical in all photocatalytical reactions. Meanwhile, the rapid growth of O2–∙ production by CoFe2O4-TiO2 is proved to be a major cause for photocatalytic performance improvement. Furthermore, an improved electrochemical ORR catalytic ability by CoFe2O4-TiO2 is verified and the 2-plus-2 electron route generates the same product (H2O2) as the photocatalytic process. Therefore, the synergistic operation of photocatalytic and catalytic ORR process by CoFe2O4-TiO2 resulted in a rapid degradation of dye wastewater.

Synthesis and characterization of nano α-Fe2O3/Mn2P2O7 for photocatalytic decomposition of p-xylene: using Box-Behnken design

α-Fe2O3/Mn2P2O7 photocatalyst was synthesized by forced hydrolysis and reflux condensation (FHRC) method. In order to fully evaluate of the structure, chemical composition and morphology of synthesized composite, various analyses such as XRD, FT-IR, BET, EDX, SEM were applied. In this research, para-xylene was selected as the model substance for photocatalytic reactions to evaluate catalytic ability. To investigate the effect of parameters and selecting the optimum condition for the understudied process, Box Behnken Design (BBD) due to the Response Surface Methodology (RSM) was performed. For this purpose, catalyst concentration, hydrogen peroxide concentration, initial p-Xylene concentration and, pH was selected as important and effective variables. Results showed that the optimized degradation efficiency was close to 96.68% within 90 min. Based on the results, it was found that the initial concentration of p-Xylene had the greatest effect on the removal of contamination. Moreover, it was determined that the photocatalytic efficiency of the synthesized composite is more favorable than the non-supported α-Fe2O3.

Glutathione capped inverted core-shell quantum dots as an efficient photocatalyst for degradation of organic dyes

Herein, we focused on the preparation of Glutathione (GHS) capped ZnS, CdS and inverted type-I ZnS@CdS core-shell quantum dots (QDs) through reflux condensation method. The XRD and HR-TEM analysis confirms the formation of core-shell QDs with corresponding crystal structures. The optical properties and band energy of the as prepared samples were evaluated from optical absorption study. The blue shift of absorption was observed in the core-shell QDs system which may be due to the quantum size effect. The EDX and elemental mapping study confirm the existence of Zn, Cd and S elements in the as-prepared material. When compared to ZnS and CdS QDs, the as prepared ZnS@CdS QDs shows improved photocatalytic activity toward the MB dye degradation due to the effective separation of the photogenerated electron-hole pair. The inverted ZnS@CdS core-shell structure not only enhances the light absorption also to reduce the charge recombination of the photocatalysts for the effective charge and energy transfer between the components during degradation. Finally, the scavenging activity and reusability of the ZnS@CdS core-shell QDs samples were examined under UV–Vis. Light irradiation.

Heterogeneous catalytic ozonation of oxalic acid with an effective catalyst based on copper oxide modified g-C3N4

Various amounts of copper oxide (CuO) modified graphitic carbon nitride (g-C3N4) denoted as CuO-CNx composites were successfully fabricated via a reflux condensation method and used as efficient ozonation catalysts for oxalic acid (OA) degradation in aqueous solution. The BET, FT-IR, HRSEM, TEM, XPS, etc. characterizations revealed the chemical composition, bond structure and morphologies of as-prepared CuO-CNx composites. The results indicated that the introduction of CuO into g-C3N4 relying on the chemical interaction rather than simple physical mixture. Moreover, the increased active sites and the intense chemical bonds could play important roles in improving the catalytic ozonation performances of CuO-CNx composites. In this study, the practical applications of catalysts at different conditions were also investigated. When the mass ratio of CuO/g-C3N4 was 10, the CuO-CN10 composite exhibited superior catalytic ozonation activity with 97.9% OA removal efficiency after 30 min at pH 5.0. Meanwhile, the CuO-CN10 showed excellent stability and reusability for contaminant degradation during multiple consecutive cycles. Furthermore, hydroxyl radical and superoxide radical as the major reactive radicals were identified and the catalytic mechanism for OA degradation improvement was also elucidated. Overall, this work would provide an efficient and eco-friendly catalyst for water treatment as well as a new idea for future environmental purification.