Facile Co-precipitation Process Research Articles

Degradation of TCH by Fe3O4/B4C catalyzed heterogeneous Fenton oxidation

In this work, Fe3O4/B4C (FeB) composites were successfully prepared by a facile co-precipitation process. FeB composites were characterized using XRD, FTIR, N2 adsorption-desorption, XPS, etc techniques and then used as heterogeneous Fenton catalysts to activate green oxidant (H2O2) for the degradation of TCH. The removal efficiency of TCH by FeB composites was explored including different parameters of Fe3O4 loading on B4C, catalyst dosage, initial solution pH, H2O2 dosage, and reaction temperature. The highest photo-Fenton catalytic efficiency was obtained for the composites with a mass ratio of Fe3O4 to B4C of 1:0.75. At this time, the removal efficiency of Fe3O4/B4C was 2 times and 391 times that of the parent Fe3O4 and B4C, respectively, and B4C can effectively improve the efficiency of the Fenton cycle. h+, e-, and ·OH were mainly responsible for the degradation of TCH by Fe1B0.75 composites. After repeated use for five times, the removal efficiency of the catalyst was reduced by only 8.0%. The disparity in work functions by density functional theory calculations confirmed the formation of an internal electric field at the Fe3O4/B4C composites interface, which contributed the transfer of charge carriers between the Fe3O4 and B4C. Moreover, the FeB composite showed a high stability, indicating that FeB composites may be a promising heterogeneous catalyst.

Control of Gradient Concentration Prussian White Cathodes for High-Performance Potassium-Ion Batteries.

Owing to their abundant resources and low cost, potassium-ion batteries (PIBs) have become a promising alternative to lithium-ion batteries (LIBs). However, the larger ionic radius and higher mass of K+ propose a challenging issue for finding suitable cathode materials. Prussian whites (PWs) have a rigid open framework and affordable synthesis method, but they suffer quick capacity fade due to lattice volume change and structural instability during K+ insertion/extraction. Here, we prepared controllable gradient concentration KxFeaNibMn1-a-b[Fe(CN)6]y·zH2O particles via a facile coprecipitation process, demonstrating high-performance potassium-ion storage. The high-Mn content in the interior can minimize capacity loss caused by electrochemically inert Ni and achieve a high reversible capacity; meanwhile, the high-FeNi content in the exterior can alleviate the volume change of the core material upon cycling, thus enhancing structural stability. Taking the above synergistic effect, the controllable gradient concentration PWs deliver a high reversible capacity of 109.8 mAh g-1 at 100 mA g-1 and good capacity retention of 77.8% after 200 cycles. The gradient concentration PWs can retain structural integrity and stability during long-term cycling. This work provides a prospective strategy to fabricate PWs with stable structure and excellent electrochemical performance for developing high-performance PIBs.

Structural and optical properties of composite phosphor Thx(MoO4)2/Bi2(1-x)Mo2O9; [formula omitted] doped with Ho3+/Yb3+ as a multifunctional materials

Composite phosphor’s, Thx(MoO4)2/Bi2(1-x)Mo2O9:2Ho3+/5Yb3+ have been synthesized cumulatively by facile co-precipitation process in ethylene glycol (EG) medium and subsequently placed for calcinations. Rietveld refinement of XRD patterns and FTIR analysis confirms the phase formation with a systematic variation of individual phases in dual-phase composite system [Th(MoO4)2-Orthorhombic; β-Bi2Mo2O9-Mononclinic]. Phase-dependent UV-Vis absorption of REs ions (Ho3+/Yb3+) has been observed and the difference between the optical bandgap of both phases leads to show the different aspect of the efficacy of optical properties. PL emission spectra of these phosphors show a strong green, relatively weak red and NIR emissions under λexci= 450 nm. The Yb3+ ions in the phosphor act as sensitizer and responsible for commencing the efficient UC emission, which shows nearly identical emission behavior under 980 nm excitation. Drastic changes in emission intensity (UC/DC) are observed with a relative dual-phase variation. Basically, the different crystal field scenarios around REs ions pertaining to both phases are responsible for the changes in emission intensity. The properties like dual-mode emission, phase dependent emission, color tuning properties, make them multifarious, that can be used for biological cell imaging, phototherapy, optical switching, display devices, solar cells, LEDs, etc.

Magnetic CoFe2O4@HAp-GQDs nanocomposites for removal of Brilliant crysel blue dye using FCCD optimization and adsorption characterization

A novel adsorbent CoFe2O4@HAp-GQDs nanocomposites were synthesized through the facile co-precipitation process and used for the removal of Brilliant Cresyl Blue (BCB) dye from aqueous solutions for the first time. FESEM, XRD, EDX, FT − IR, and VSM techniques were used to characterize the prepared nanocomposites. To optimize BCB removal by CoFe2O4@HAp-GQDs, a face-centered central composite design (FCCD) with three levels was utilized. The maximum removal percent (93 %) of BCB was obtained at the optimum conditions of initial dye concentration of 221 mg L−1, 0.05 g adsorbent amount, and pH 5.7. The experimental equilibrium data were examined by D-R, Langmuir, Temkin, and Freundlich isotherm models. The adsorption isotherm follows the Langmuir model with a maximum adsorption capacity of about 139.4 mg g−1. Adsorption kinetic data were also considered using pseudo 1st order, Elovich, pseudo 2nd order, and intra-particle diffusion models. Thermodynamic results show that the BCB dye was adsorbed exothermically, and spontaneously.

Achieving high-efficiency and broad bandwidth with low filler loading for hierarchical Fe3O4/Co-MOF absorbers

Metal-organic frameworks (MOFs) with intrinsic porosity and high specific surface area have aroused broad interests as a promising electromagnetic (EM) absorbing material. However, the introduction of magnetic components in MOFs has remained as a formidable obstacle for subsequent development. Herein, Fe3O4/Co-MOF composites were fabricated via a facile and scalable co-precipitation process. The microstructure and morphology of the composites were characterized and the combination of hollow Fe3O4 and Co-MOFs was found to contribute towards the dissipation of incident waves due to the magnetic-dielectric synergistic effect. Impressive microwave absorption ability was obtained with a minimum reflection loss of –56.1 dB over a qualified bandwidth (7.9 GHz) at 2.0 mm. Moreover, the radar cross section simulation further confirmed the effective suppression of radar wave scattering using Fe3O4/Co-MOF composites. This study provides a versatile strategy for designing magnetic-dielectric composites based on MOFs as effective and broadband microwave absorbers.

Halogen doped g-C3N4/ZnAl-LDH hybrid as a Z-scheme photocatalyst for efficient degradation for tetracycline in seawater

The present research centered on the fabrication of halogen (F and Cl) doping g-C3N4 modified ZnAl-LDH (FCCN/LDH) nanohybrids and its application in the photodegradation of tetracycline (TC) in artificial seawater. Halogen doping g-C3N4 was prepared via hydrothermal and thermal polycondensation methods using melamine as the precursor. Heterostructural FCCN/LDH binary nanocomposites were synthesized by a facile co-precipitation process. The morphological analysis of binary heterojunction exhibited uniformed decoration of FCCN on the LDH nanosheet surface. FCCN/LDH hybrid displayed enhanced photocatalytic degradation efficiency in the artificial seawater compared with pure FCCN and LDH, which is attributed to appropriate band alignment and Z-scheme electron-hole pairs transfer mechanism to suppress the recombination of photogenerated charge carriers. Electrochemical properties and PL results confirmed the proposed mechanism for extended visible-light response range over FCCN/LDH nanocomposites. Finally, the degradation efficiency of other pollutants (MB, MO, CIP, Rh B, and Cr(VI)) and the photocatalytic stability over FCCN/LDH nanocomposites in the seawater system were also reconnoitered. The plausible Z-scheme mechanism signposted that h+ and O2– active species are foremost free radicals that play a pivotal role in photodegradation.

Efficient Photocatalytic Dye Degradation and Bacterial Inactivation by Graphitic Carbon Nitride and Starch-Doped Magnesium Hydroxide Nanostructures.

The removal of hazardous pollutants from water is becoming an increasingly interesting topic of research considering their impact on the environment and the ecosystem. This work was carried out to synthesize graphitic carbon nitride (g-C3N4) and starch-doped magnesium hydroxide (g-C3N4/St-Mg(OH)2) nanostructures via a facile co-precipitation process. The focus of this study is to treat polluted water and bactericidal behavior with a ternary system (doping-dependent Mg(OH)2). Different concentrations (2 and 4 wt %) of g-C3N4 were doped in a fixed amount of starch and Mg(OH)2 to degrade methylene blue dye from an aqueous solution with bactericidal potential against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) pathogens. The textural structures, morphological evolutions, and optical characteristics of the as-prepared samples were analyzed using advanced characterization techniques. X-ray diffraction confirmed the hexagonal phase of Mg(OH)2 with improved crystallinity upon doping. Fourier transform infrared spectroscopy revealed Mg(OH)2 stretching vibrations and other functional groups. UV-visible spectroscopy exhibited a red shift (bathochromic effect) in absorption spectra representing the decrease in energy band gap (E g). Photoluminescence patterns were recorded to study recombination of charge carriers (e- and h+). A significant enhancement in photodegradation efficiency (97.62%) and efficient bactericidal actions against E. coli (14.10 mm inhibition zone) and S. aureus (7.45 mm inhibition zone) were observed for higher doped specimen 4% g-C3N4/St-Mg(OH)2.

Non-enzymatic glucose sensor fabricated by CoFe2O4 nanosheets grown on Reduced Graphene Oxide

ABSTRACT A non-enzymatic glucose sensing nanocomposite comprised of CoFe2O4 nanosheets grown on Reduced Graphene Oxide (CoFe2O4@rGO) has been triumphantly prepared by a facile co-precipitation process. The characterisation results reveal that the CoFe2O4 nanosheets are vertically grown on the rGO substrate and form a porous network structure. Next, Electrochemical workstation is applied to study the glucose detection performance of the CoFe2O4@rGO. The sensing tests exhibit that when the volume ratio of anhydrous ethanol and deionised water is 10 ml: 30 ml, the fabricated CoFe2O4@rGO has better glucose detection performance. Its linear detection ranges from 0.5 mM – 10 mM and 10 mM – 35 mM, and the sensitivity reaches 50.5 μAmM−1cm−2 and 143.6 μAmM−1cm−2 respectively, which is significantly better than the previously reported non-enzyme glucose sensing materials. Furthermore, the CoFe2O4@rGO has good anti-interference and stability.

Designing a multifunctional nanoplatform based on PEGylated cobalt ferrite magnetic nanoparticles containing capecitabine for cancer theranostics

Anticancer drugs can be delivered more efficiently to tumor sites with fewer side effects by utilizing magnetic nanoparticles. In this research detailed examinations of the effect of polyethylene glycol (PEG) on microstructure, size distribution, morphology, magnetic performance and coating of cobalt ferrite nanoparticles (CFO) were conducted. CFO nanoparticles were functionalized by PEG under different conditions, using a facile co-precipitation process. X-ray diffraction (XRD) patterns confirmed that all detected peaks were related to the cubic single-phase spinel structure. Fourier transform infrared spectroscopy (FTIR) revealed the chemical interactions between CFO and PEG. The results of field emission scanning electron microscopy (FE-SEM) showed a uniform spherical morphology with a mean size of 24, 32, and 40 nm at PEG molecular weights of 600, 1500 and 6000, respectively. Furthermore, vibrating sample magnetometer (VSM) revealed that saturation magnetization of nanoparticles decreased by coating with PEG. Results also confirmed that PEG with a higher molecular weight created a thicker coating on CFO. Estimation of capecitabine anticancer drug loading in CFO-PEG nanoparticles investigated by UV-VIS spectroscopy indicated that composite nanoparticles with a PEG molecular weight of 6000 had the highest loading efficiency of 13.67%. Over 40% of capecitabine was released in tumor-like acidic pH (5.5) compared to 23% in normal tissue pH (7.4). Nanoparticles proved blood biocompatible in terms of hemolysis up to a high concentration of 800 μg/ml. Eventually, magnetic resonance imaging (MRI) analyses displayed that CFO-PEG6000 nanoparticles with a relaxivity of 81.12 mM−1 S−1 can be successfully used as an MRI contrast agent. Overall, the developed multifunctional CFO-PEG nanoparticle with potential localized and efficient drug delivery and favorable imaging capability is a promising candidate as a cancer theranostic nanoplatform.

Highly selective adsorption and lattice process of cesium by cubic cyanide-based functional materials

Cesium (Cs) is a byproduct of nuclear bombs, nuclear weapons testing, and nuclear fission in nuclear reactors. Cs can enter the human body through food or air and cause lasting damage. Highly efficient and selective removal of 137Cs from low-level radioactive effluents (LLREs), which contain many radionuclides and dissolved heavy metal species, is imperative for minimizing LLRE volume, and facilitating their final disposal. Prussian blue analogs (PBAs) have received much attention as materials for the removal of radioactive Cs because of their affinity for adsorbing Cs+. In this study, an inexpensive and readily available cyanide-based functional material (PBACu) exhibiting high efficiency and excellent selectivity toward Cs capture was designed through a facile low-temperature co-precipitation process. Nano-PBACu, crystallizing in the cubic space group (Fm-3m (225)), has an average pore size of 6.53 nm; consequently, PBACu can offer abundant atomic occupation sites for capturing and incorporating Cs. Here, the pseudo-second-order kinetic model and Langmuir model fitted well with the adsorption of Cs + on PBACu, with a maximum capture capacity of 95.75 mg/g within 5 min, confirming that PBACu could rapidly capture Cs ions. PBACu strongly and selectively interacted with Cs even in a simulant containing large Na+, NH4+, Ca2+, and Mg2+ ion concentrations in an aqueous solution. The process of Cs + adsorption by cyanide-based functional crystals was confirmed to involve the entry of Cs+ into cyanide-based functional crystals to replace K+ and finally achieve the lattice incorporation of Cs. The current results broaden the lattice theory of radionuclide Cs removal and provide a promising alternative for the immobilization of Cs from radioactive wastewater.

Facile coating of the methotrexate-layered double hydroxide nanohybrid via carboxymethyl starch as a pH-responsive biopolymer to improve its performance for colon-specific therapy

In view of biopolymer's importance in the drug delivery area, this study aimed to investigate the potential of a new drug carrier based on methotrexate-loaded layered double hydroxide (ZnAl-LDH/MTX) and carboxymethyl starch (CMS) as a specific intestinal delivery vehicle. Briefly, the ZnAl-LDH was first synthesized via a facile co-precipitation process and then the MTX was loaded on it. MTX loading capacity of ZnAl-LDH was calculated up to ∼23.7%. FT-IR, UV–Vis, and XRD analysis confirmed the successful formation of ZnAl-LDH/MTX. ZnAl-LDH/MTX released about 100% of the loaded MTX in the initial 2 h in simulated stomach media. To overcome this challenge the ZnAl-LDH/MTX was coated with CMS (CMS@ZnAl-LDH/MTX). The CMS@ZnAl-LDH/MTX displayed limited drug releases at pH 1.2 and a higher percentage of the drug was released at pH 6.8 and 7.4; owing to the pH-responsive nature of CMS. The CMS@ZnAl-LDH exhibited good biocompatibility, but CMS@ZnAl-LDH/MTX was toxic toward the studied cell line. In comparison to the pristine LDHs based drug carriers, the controlled and sustained drug delivery of CMS@ZnAl-LDH/MTX could be a valuable advantage for it, so, the results strongly suggest the potential of CMS@ZnAl-LDH/MTX with biodegradable nature for controlled drug delivery to the lower gastrointestinal tract.

An investigation on the promoting effect of Pr modification on SO2 resistance over MnOx catalysts for selective reduction of NO with NH3.

Pr-modified MnOx catalyst was synthesized through a facile co-precipitation process, and the results showed that MnPrOx catalyst exhibited much better selective catalytic reduction (SCR) activity and SO2 resistance performance than pristine MnOx catalyst. The addition of Pr in MnOx catalyst led to a complete NO conversion efficiency in 120-220°C. Moreover, Pr-modified MnOx catalyst exhibited a superior resistance to H2O and SO2 compared with MnOx catalyst. After exposing to SO2 and H2O for 4h, the NO conversion efficiency of MnPrOx catalyst could remain to 87.6%. The characterization techniques of XRD, BET, hydrogen-temperature programmed reduction (H2-TPR), ammonia-temperatureprogrammed desorption (NH3-TPD), XPS, TG and in situ diffuse reflectance infrared spectroscopy (DRIFTS) were adopted to further explore the promoting effect of Pr doping in MnOx catalyst on SO2 resistance performance. The results showed that MnPrOx catalyst had larger specific surface area, stronger reducibility, and more L acid sites compared with MnOx catalyst. The relative percentage of Mn4+/Mnn+ on the MnPrOx-S catalyst surface was also much higher than those of MnOx catalyst. Importantly, when SO2 exists in feed gas, PrOx species in MnPrOx catalyst would preferentially react with SO2, thus protecting the Mn active sites. In addition, the introduction of Pr might promote the reaction between SO2 and NH3 rather than between SO2 and Mn active sites, which was also conductive to protect the Mn active sites to a great extent. Since the presence of SO2 in feed gas had little effect on NH3 adsorption on the MnPrOx catalyst surface, and the inhibiting effect of SO2 on NO adsorption was alleviated, SCR reactions could still proceed in a near-normal way through the Eley-Rideal (E-R) mechanism on Pr-modified MnOx catalyst, while SCR reactions through the Langmuir-Hinshelwood (L-H) mechanism were suppressed slightly.

In doping effect on the structural, morphological, optical and enhanced antimicrobial activity of facilely synthesized novel CuS nanostructures

In this paper, we report the impact of Indium on the structural, morphological, optical, and antibacterial properties of copper sulfide (CuS) nanoparticles produced by facile chemical Co-precipitation process. X-ray diffraction, Raman, scanning electron microscope and X-ray photoelectron spectroscopy techniques were used to investigate the phase composition and purity. Antibacterial tests were performed by well diffusion method and growth kinetics assay. The hexagonal structure of CuS nanoparticles is revealed by XRD/Raman analysis, with crystallite size ranging from 6 to 11 nm. SEM pictures also revealed a larger crystallite size with the addition of indium doping. For maximum indium doping (5 wt.%), the morphology was modified from nanoparticle to nanosheet. The existence of indium dopant was also confirmed by XPS analysis. The energy band gap shifted from 2.16 – 2.47 eV with altering indium concentrations in CuS. Indium doped CuS NPs exhibited highest antibacterial effect against Mycobacterium smegmatis (20–24 mm) while Pseudomonas aeruginosa had the lowest antimicrobial activity (12–14 mm). Growth kinetics study delineated that In:CuS had high antibacterial efficacy against all the tested microbial strains and suppress the microbial growth in the logarithmic growth phase. Hence, In:CuS might be applied as antimicrobial coatings to inhibit microbial biofilm development.

Fe3O4-Bi2O3 nanostructures for efficient energy generation application-water oxidation under visible light irradiation

• Facile synthesis of Fe 3 O 4 -Bi 2 O 3 nanostructures for energy generation applications. • Fe 3 O 4 -Bi 2 O 3 nanostructures showed highest photocurrent density. • The lowest charge transfer resistance is achieved for Fe 3 O 4 -Bi 2 O 3 nanostructures. • Potentiodynamic of Fe 3 O 4 -Bi 2 O 3 nanostructures showed enhanced properties. Nanostructures of Fe 3 O 4 , Bi 2 O 3 , and Fe 3 O 4 -Bi 2 O 3 were synthesized by a facile coprecipitation process for energy generation applications. Various analyses are carried out to confirm the formation of the nanostructures. The prepared samples showed cube structures with optical bandgaps of 2.21, 2.50, and 2.32 eV for the Fe 3 O 4 , Bi 2 O 3 , and Fe 3 O 4 -Bi 2 O 3 nanostructures, respectively. In the X-ray photoelectron spectroscopy analysis, Fe 2+ , Fe 3+ , Bi 3+ , and Bi 5+ chemical states were observed for the Fe 3 O 4 -Bi 2 O 3 nanostructures. The lowest charge transfer resistance of 46.04 Ω and ion-conducting path resistance of 26.11 Ω were observed in electrochemical impedance spectroscopy in 0.1 M KOH for Fe 3 O 4 -Bi 2 O 3 nanostructures compared with other samples. In the potentiodynamic analysis of the Fe 3 O 4 -Bi 2 O 3 nanostructures, the enhanced Tafel slopes, exchange current density, and limiting diffusion current density under illumination associated with the Fe 3 O 4 and Bi 2 O 3 nanostructures. The maximum photocurrent density of 3.61 × 10 -4 Acm −2 was one order of magnitude higher than that of the pure Fe 3 O 4 and Bi 2 O 3 samples. Hence, the prepared Fe 3 O 4 -Bi 2 O 3 nanostructures can be utilized in energy generation applications.

Orange light emission from co-precipitation derived CaZr4(PO4)6 doped with Sm3+ phosphor

We report on the preparation and characterization of orange light-emitting CaZr4(PO4)6:Sm3+ phosphors using a facile co-precipitation process. The crystal structure, photoluminescence (PL), and color chromaticity coordinates of the prepared phosphors were investigated. The PL emission spectra of the synthesized CaZr4(PO4)6:Sm3+ phosphor shows a strong emission at around 556 nm, 564 nm, 598 nm, and 644 nm under 399 nm excitation, which is ascribed 4G5/2→ 6H5/2, 6H7/2, and 6H9/2 electronic transitions of the Sm3+ ions, respectively. The PL emission spectra were analyzed for various concentrations of Sm3+ ions. The maximum PL intensity was observed at the Sm3+ concentration of 0.07 mol. In the present work, the concentration quenching process occurred in the CaZr4(PO4)6:Sm3+ phosphors due to the dipole-dipole interaction mechanism. Under a 399 nm excitation wavelength, the synthesized phosphor shows a visible orange color emission with magnificent CIE coordinates and color purity. The synthesized CaZr4(PO4)6:Sm3+ phosphor shows strong orange emitting properties at around 598 nm, which will be good as an enhancement in the color index in the WLEDs. These results all indicate that the Sm3+-activated CaZr4(PO4)6 phosphors were promising orange-emitting materials for WLEDs.

Fenton Degradation of Ofloxacin Using a Montmorillonite–Fe3O4 Composite

In this work, FeM composites consisting of montmorillonite and variable amounts of Fe3O4 were successfully synthesized via a facile co-precipitation process. They were characterized using X-ray photoelectron spectroscopy (XPS), a field emission scanning electron microscope (FESEM), energy-dispersive X-ray spectroscopy (EDX), a transmission electron microscope (TEM), N2 adsorption–desorption, and Fourier transform infrared spectroscopy (FTIR) techniques to explain the effect of Fe3O4 content on the physicochemical properties of the Fe3O4–montmorillonite (FeM) composites. The FeM composites were subsequently used as heterogeneous Fenton catalysts to activate green oxidant (H2O2) for the subsequent degradation of ofloxacin (OFL) antibiotic. The efficiency of the FeM composites was studied by varying various parameters of Fe3O4 loading on montmorillonite, catalyst dosage, initial solution pH, initial OFL concentration, different oxidants, H2O2 dosage, reaction temperature, inorganic salts, and solar irradiation. Under the conditions of 0.75 g/L FeM-10, 5 mL/L H2O2, and natural pH, almost 81% of 50 mg/L of OFL was degraded within 120 min in the dark, while total organic carbon (TOC) reduction was about 56%. Although FeM composites could be a promising heterogeneous catalyst for the activation of H2O2 to degrade organic pollutants, including OFL antibiotic, the FeM-10 composite shows a significant drop in efficiency after five cycles, which indicates that more studies to improve this weakness should be conducted.

Bimetallic Sulfide/Sulfur Doped T3C2Tx MXene Nanocomposites as High-performance Anode Materials for Sodium-ion Batteries

The application of transition metal dichalcogenides(TMDs) as anode materials in sodium-ion batteries (SIBs) has been hindered by low conductivity and poor cyclability. Herein, we report the synthesis of CoxFe1−xS2 bimetallic sulfide/sulfur-doped Ti3C2 MXene nanocomposites(CoxFe1−xS2@S-Ti3C2) by a facile co-precipitation process and thermal-sulfurization reaction. The interconnected 3D frameworks consisting of MXene nanosheets can effectively buffer the volume change and enhance the charge transfer. In particular, sulfur-doped MXene nanosheets provide rich active sites for sodium storage and restrain sulfur loss during charging/discharging processes, leading the increase of specific capacity and cycling the stability of anode materials. As a result, CoxFe1−xS2@S-Ti3C2 anodes exhibited high capacity, high rate capability and long cycle life(399 m·Ah/g at 5 A/g with an 94% capacity retention after 600 cycles).

Optimization of Boron Doped TiO2 as an Efficient Visible Light-Driven Photocatalyst for Organic Dye Degradation With High Reusability.

No visible light activity is the bottle neck for wide application of TiO2, and Boron doping is one of the effective way to broaden the adsorption edge of TiO2. In this study, several Boron doped TiO2 materials were prepared via a facile co-precipitation and calcination process. The B doping amounts were optimized by the degradation of rhodamine B (Rh B) under visible light irradiation, which indicated that when the mass fraction of boron is 6% (denoted as 6B-TiO2), the boron doped TiO2 materials exhibited the highest activity. In order to investigate the enhanced mechanism, the difference between B-doped TiO2 and bare TiO2 including visible light harvesting abilities, separation efficiencies of photo-generated electron-hole pairs, photo-induced electrons generation abilities, photo-induced charges transferring speed were studied and compared in details. h+ and · were determined to be the two main responsible active species in the photocatalytic oxidation process. Besides the high degradation efficiency, 6B-TiO2 also exhibited high reusability in the photocatalysis, which could be reused at least 5 cycles with almost no active reduction. The results indicate that 6B-TiO2 has high photocatalytic degradation ability toward organic dye of rhodamine B under visible light irradiation, which is a highly potential photocatalyst to cope with organic pollution.

Mo-substituted CeVO4 system: solid solution formation and implications on sorption behaviour

Synthesis of Mo-substituted CeVO4 systems by facile co-precipitation process is reported wherein an upper solubility limit of 40 mol% Mo was obtained retaining the tetragonal structure. Solid solution formation was investigated by X-ray diffraction, X-ray fluorescence and Raman spectroscopy and XPS. Introduction of Mo into the anionic framework yielded hierarchical mesoporous structures with substantial increase in surface area from 76 to 147 m2/g as exhibited by TEM and BET analysis. Complete uptake of Pb2+ ions from aqueous solutions was shown by both CeVO4 and Mo-CeVO4 with sorption capacity of 100 mg/g. In addition, the presence of Mo in CeVO4 depicted five times faster and superior kinetics than pure CeVO4. Various isotherms have been used to model the data. This study not only unravels the structural aspects of Mo-substituted CeVO4 system but also discusses new promising sorbents for toxic Pb2+ ions obtained by simple synthetic route.

Enhanced catalytic activation of photo-Fenton process by Cu0·5Mn0·5Fe2O4 for effective removal of organic contaminants

In this study, Cu0·5Mn0·5Fe2O4 nanoparticles were synthesized through a facile coprecipitation process, evaluated as highly efficient photo-Fenton catalyst for removal of bisphenol A (BPA). Benefit for its larger surface area and unique chemical composition, the Cu0·5Mn0·5Fe2O4 catalyst exhibited superior catalytic activity toward the degradation of BPA, with a rate constant values ranging from 0.247 to 1.090 min−1 based on different operating parameters (catalyst load, initial solution pH, H2O2 concentration and reaction temperature). Importantly, an excellent BPA removal efficiency exceeding 95.2% were obtained after eight successive runs of photo-Fenton process. Electron paramagnetic resonance (EPR) spectroscopy and radical scavenger experiments demonstrated that the hydroxyl radical was the dominant radical in degradation of BPA. A possible BPA degradation pathway was proposed according to the detected intermediates by GC-MS and HPLC. In brief, this work is expected to provide a new heterogeneous photo-Fenton catalyst for the organic pollutants removal from wastewater.