ZnO TiO2 Nanoparticles Research Articles

Sun-powered Wastewater Treatment with a Hydrogen Bonus: Unveiling the Potential of Zno-Tio2 Nanoparticles

Sun-powered Wastewater Treatment with a Hydrogen Bonus: Unveiling the Potential of Zno-Tio2 Nanoparticles

Photocatalytic degradation of malachite green dye under solar light irradiation using ZnO and ZnO–TiO2 nanoparticles

Photocatalytic degradation of malachite green dye under solar light irradiation using ZnO and ZnO–TiO2 nanoparticles

Synthesis of ZnO-TiO2 Nanoparticles by Sol-Gel Process and its Application for Solar Cell Semiconductor

ZnO-TiO2 semiconductor can be used in Dye-Sensitized Solar Cell (DSSC) devices as an alternative to renewable energy. This semiconductor can be synthesized by sol-gel method. The objective of this study is synthesizing the TiO2-doped ZnO nanoparticle semiconductors for DSSC devices with mangosteen peel extract dye. Avocado seeds were extracted with water, as a capping agent in the synthesis of ZnO-TiO2 (TiO2 ratio of 0,3,5,7 and 10% to ZnO). XRD results show the success of ZnO-TiO2 doping, due to the 2θ shift and changes in the crystal lattice. The average crystal size obtained was 33.7972 nm. The SEM results showed that the particle size of ZnO ranged from 45-100 nm. The UV-Vis dye measurements of mangosteen peel extract showed an absorption peak at 296-483 nm wavelength, with a corresponding band gap energy value of 3.04 eV. The UV-Vis DRS ZnO-TiO2 measurements have an average band gap energy of 3.1425 eV and ZnOof 3.1915 eV. The highest DSSC efficiency value is 2.15 x 10-2% at 7% ZnO-TiO2 semiconductor.

Facile synthetic route of TiO2–ZnO heteronanostructure coated by oxovanadium (IV) bis-Schiff base complex as a potential effective homogeneous/heterogeneous catalysts for alcohols redox systems

Oxovanadium (IV) bis-Schiff base complex was synthesized by a facile complexation of 2 molar ratio of 2‑hydroxy-Schiff base ligand (HL) with 1 molar ratio of VO2+ ion giving mononuclear VOL2 complex with a square pyramidal geometry. The structure conformation of HL and its corresponding VOL2 complex was assigned within various spectroscopic tools (IR, UV–vis. Mass spectra), as well as the elemental analyses (EA). The deprotonated 4-OH group in VOL2 caused a successful coating of VOL2 on a mixed oxides of TiO2–ZnO nanoparticles awarding nanocomposite of TiO2–ZnO@VOL2. By applying alternative analytical techniques, the surface morphology and internal structure TiO2–ZnO@VOL2 nanocomposites were investigated compared to that of TiO2–ZnO, i.e. by XRD, FESEM, HR-TEM, EDS and IR spectra), and also with TGA and BET (adsorption–desorption isotherm).The catalytic effectiveness of both homogeneous and heterogeneous catalysts (VOL2 and TiO2–ZnO@VOL2) was examined in the productive oxygenation reactions of BA (benzyl alcohol) by an aqueous hydrogen peroxide under an aerobic environment to the chemo-selective product benzaldehyde (BZ), and benzoic acid (BO), as the overodixation product. Both VOL2 and TiO2-ZnO@VOL2 catalysts exhibited obvious classified action by 89% and 91% yielding amount of benzaldehyde after 4 h for reaction temperature 80 and 90 °C, respectively. The differentiation between them in the catalytic reactivity was depending on the heterogeneity and the effect of the coated TiO2–ZnO nanoparticles on the VOL2 catalytic potential. The kinetic parameter of the productive redox protocols for both catalyst was examined. Additionally, some other cyclic and acyclic alcohols were exhibited the productive redox protocol in the optimum control of both catalysts.

Structural and electronic properties of PANI-ZnO-TiO2 nanocomposite

The nanocomposites of doped Polyaniline (PANI) with ZnO-TiO2 nanoparticles have been prepared by in-situ polymerization method. The structural properties of synthesized PANI and PANI/ZnO-TiO2 were studied by X-ray diffraction (XRD) analysis. XRD pattern show that PANI is intercalated into the layers of ZnO-TiO2 successfully and thus the degree of crystallinity increases due to crystalline nature of ZnO-TiO2. FTIR analysis indicated that there is a strong interaction between ZnO-TiO2 nanoparticles and PANI. Electronic properties (Dielectric and Conductivity) of PANI and PANI/ZnO-TiO2 nanocomposite have been investigated between frequency ranges from 20Hz to 01MHz, higher dielectric constants and dielectric losses of PANI/ZnO-TiO2 nanocomposites were found. As the content of ZnO-TiO2 increased, the dielectric constant and loss also increased. The value of dielectric constant for all samples is very high at low frequency but decreases with increase in frequency. Synthesis of PANI/ZnO-TiO2 nanocomposite materials with a large dielectric constant is promising for charge storage devices applications

Preparation of Cellulose Acetate Nanocomposite Films Based on TiO2-ZnO Nanoparticles Modification as Food Packaging Applications

To develop bio-packaging materials, nanocomposite films of cellulose acetate reinforced with titanium dioxide and zinc oxide nanoparticles were prepared, by the casting method at different weight ratios of ZnO nanoparticles (1.5, 2, and 2.5) wt% and a constant weight ratio of 2 wt% TiO2. ZnO and TiO2 nanoparticles were tested using scanning electron microscopy (SEM). The mechanical properties (tensile strength and elongation) were improved at a fixed level of Cellulose Acetate+ 2% TiO2+1.5wt% ZnO loading. Beyond that level of loading, they decreased. The tensile strength was decreased due to some degrees of agglomeration of filler particles above a critical content. Fourier-Transform Infrared Spectroscopy (FTIR) was conducted to reveal the microstructures and chemical composition of as-prepared composite films. The wettability of the films was also determined by the sessile drop method. An increase in contact angle was also observed by the addition of ZnO content from 70.6° to 77.1° compared to pure Cellulose Acetate, which indicated a value of 61.3°. Antibacterial activity against Escherichia coli and Staphylococcus aureus was enhanced after incorporation of ZnO-TiO2 compared with pure CA. The enhanced wettability and antibacterial activity of the prepared films suggest that they could be used for packaging applications.

Evaluation of performance characteristics of nano TiO2 and TiO2-ZnO composite for DSSC applications and electrochemical determination of potassium ferrocyanide using cyclic voltammetry

Nanoparticles of TiO2 and TiO2-ZnO composite (2:1 molar ratio) were synthesized utilizing the sol-gel and solution combustion approaches, respectively. Scanning electron microscopic, energy dispersive x-ray, x-ray diffraction, UV-visible spectroscopy, and Brunauer–Emmett–Teller analysis were employed to characterize the synthesized nanoporous TiO2 and the composite of TiO2-ZnO nanoparticles. Fabrication of dye-sensitized solar cells (DSSCs) was carried out by incorporating the synthesized nanoporous materials coating on the photoanodes using the doctor blade technique. Nano TiO2 and the composite of TiO2-ZnO were also analyzed using cyclic voltammetry test, and their performance was compared for the electrochemical detection of potassium ferrocyanide. The composite of TiO2-ZnO exhibited better electrocatalytic activity in comparison with the pure TiO2 nanoparticles. The fabricated DSSCs by employing nano TiO2 particles and TiO2-ZnO composite as the semiconductor photoanode materials were compared for photovoltaic performance. The DSSC fabricated with TiO2 nanoparticles exhibited better photovoltaic performance with an efficiency of 2.22% and a current density of 4.152 mA cm−2 than that fabricated with TiO2-ZnO composite with an efficiency of 0.0022% and a short circuit current density of 0.014 mA cm−2.

Fabrication of binary (ZnO)x(TiO2)1−x nanoparticles via thermal treatment route and evaluating the impact of various molar concentrations on the structure and optical behaviors

Numerous studies have explored the behaviors of ZnO–TiO2 nanoparticles resulting through various routes of fabrication. To date, the utilization of thermal treatment method to convey ZnO–TiO2 nanoparticles has never been considered. In the present study, binary (ZnO)x(TiO2)1−x NPs were effectively blended by using thermal treatment technique. Zinc nitrate and titanium(IV) propoxide with polyvinylpyrrolidone, PVP, were utilized to set up the samples. Energy-dispersive X-ray (EDX) spectroscopy, Fourier-transform infrared spectroscopy, X-ray diffraction (XRD) spectroscopy, ultraviolet–visible (UV–Vis) spectrophotometer transmission electron microscopy (TEM) and photoluminescence spectroscopy were utilized to examine the impact of changing the molar proportion to the structure and optical features of (ZnO)x(TiO2)1−x NPs. The XRD spectra revealed that after calcination, the amorphous sample had transformed into crystalline nanoparticles. The prepared (ZnO)x(TiO2)1−x NPs average diameter was around 25.922–28.531 nm according to TEM analysis. The analyzation of UV–Vis spectroscopy determined the optical measurements parameters including the energy gap and Urbach energy of binary (ZnO)x(TiO2)1−x NPs. The optical energy gap varied in the range of 3.2496–3.2863 eV as the molar ratio increases from x = 0.24 to x = 0.72. The enhancement within the nanoparticles optical properties suggests a good potential for photocatalysis application.

Preparation ultrafine l-Methionine (C,N,S triple doped)-TiO2-ZnO nanoparticles and their photocatalytic performance for fouling alleviation in PES nanocomposite membrane

TiO2, and ultrafine l-Methionine (C,N,S triple doped)-TiO2-ZnO nanoparticles (NPs) were synthesized and blended in polyethersulfone (PES) matrix with various loadings (0.1, 0.5, and 1 wt %). The prepared nanoparticles (NPs) were characterized by XRD, FT-IR, FE-SEM, PL, and DRS analyses. The effect of embedded NPs on the morphology and hydrophilic properties of the fabricated membranes was also analyzed by AFM, SEM and contact angle measurement. The results showed that the membrane structure (morphology and porosity) and its hydrophilic properties are changed with addition of the NPs in the PES casting solution. Results showed that the membrane hydrophilicity and permeation flux improved by embedding the NPs in the PES mix matrix. The influence of embedded NPs on the membrane performance and antifouling properties was also studied in a dead end and cross flow systems. The nanofiltration performance was investigated by rejection of Direct Red 16 (DR16). The results indicated that 0.5 wt % of the NPs had the highest pure water flux (PWF), flux recover ratio (FRR), and rejection efficiency compared to the other concentrations of NPs. Finally, the photocatalytic properties of the M3 (optimum blended membrane) and unfilled PES was investigated in a cross flow system for filtration of biologically treated palm oil mill effluent (POME) under continuous visible light irradiation. The value of permeation flux for unfilled PES membrane showed a significant decline while it was not obviously changed for M3 during filtration biologically treated POME under continuous visible light irradiation. The results revealed that the M3 membrane presented the best antibiofouling characteristics due to high hydrophilic properties and low surface roughness and strong photocatalytic activity.

Tuning the photocatalytic properties of sol–gel-derived single, coupled, and alloyed ZnO–TiO2 nanoparticles

Existing industrial titania production lines and their intermediate products are economically attractive precursors for synthesis of highly concentrated TiO2 coating sols and soluble nanopowders. Refluxing of aliphatic alcoholic TiOCl2 solutions (with up to 500 g TiO2/L) allows straightforward formation of nonaggregated anatase nanocrystals with size between 5 and 8 nm. Surface modification of these nanoparticles with organosilanes shifts the pH value of point of zero charge from initially 5.3 down to around 2.8. At appropriate Ti/Si ratios, complete suppression of the anatase ultraviolet (UV) photoactivity is possible. Furthermore, we address the optical and photocatalytic data of transparent nanocrystalline layers produced from superconcentrated ZnxTiyOz heterosols. Depending on the Zn/Ti ratio and processing temperature, colorless cubic c-ZnTiO3 and c-Zn2TiO4 spinel nanophases or coupled r-ZnTiO3-ilmenite/r-TiO2-rutile heterojunctions (Zn/Ti = 2/3) can be produced. The cubic spinel films are indirect semiconductors showing band gap transition of around 3.7 eV. In contrast, r-ZnTiO3-ilmenite films have slightly lower band gap of around 3.6 eV. Organic dye photodegradation studies reveal the highest catalytic activity for the coupled r-ZnTiO3-ilmenite/r-TiO2-rutile systems compared with colored (nitridated) or colorless cubic spinel film samples.

Comparison of the adsorption of H2S by ZnO–TiO2 and Ni–ZnO–TiO2 nanoparticles: An adsorption isotherm and thermodynamic study

AbstractNanoparticles were synthesized by the sol–gel method and evaluated for adsorption of hydrogen sulfide using a continuous fixed‐bed column. The effects of the parameters were examined, and the optimum values for nanoparticles were found to be mass of adsorbent 0.2 g, gas volume 5.7 L, flow rate 0.22 L min−1, and gas pressure 7 Psi at 12 °C. These conditions resulted in a maximum adsorption of H2S of 83.24% and 90.43% for ZnO–TiO2 and Ni–ZnO–TiO2 nanoparticles, respectively. The equilibrium data were best represented by the Freundlich isotherm. The thermodynamic parameters indicated that the adsorption was spontaneous and exothermic in nature.

Fabrication and characterization of ZnO-TiO2-PANI (ZTP) micro/nanoballs for the detection of flammable and toxic gases.

The present paper reports the in-situ chemical polymerization of nanocomposites thin film composed by titanium dioxide (TiO2), zinc oxide (ZnO) and polyaniline (PANI). It was found that nanocomposites sensor is highly selective and shows response to low concentration. To improve the sensing response characteristics of ZT thin film, PANI is incorporated. Thin film based LPG sensor of ZnO-TiO2-PANI composite was fabricated by spin coating of ZnO-TiO2 nanoparticles doped with PANI over inter digital electrodes (IDEs). The thin film was characterized by using XRD, SEM, TEM, UV-vis, BET and FTIR. It was also tested for gas sensing properties of LPG/NO2 which are well known flammable and toxic gases. The measured response for ZnO-TiO2-PANI based sensor was 87 for 2000 ppm of LPG and 412 for 20 ppm of NO2 at room temperature towards other testing gases together with Acetone, IPA, NH3 and CO2.

Antimicrobial activity of ZnO-TiO2 nanomaterials synthesized from three different precursors of ZnO: influence of ZnO/TiO2 weight ratio

In this study, ZnO-TiO2 nanoparticles were synthesized from three different precursors for ZnO (zinc acetate di-hydrate, zinc nitrate hexahydrate and zinc sulfate heptahydrate) and titanium (IV) isopropoxide for TiO2. The prepared nanomaterials were calcined at 500 °C for 3 h and characterized by various physicochemical techniques such as X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR) and transmission electron microscopy, combined with energy dispersive X-ray spectroscopy (TEM-EDS). The obtained results showed that the crystalline structure, size and morphology of the ZnO-TiO2 nanoparticles are strongly influenced by the nature of the precursor of ZnO, as well as the ZnO/TiO2 weight ratio. The antibacterial and antifungal activities of the synthesized nanomaterials were evaluated, in the dark, against five multi-resistant of Gram positive (Staphylococcus aureus) and Gram negative (Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa and Salmonella Paratyphi A) bacteria and a fungus (Candida albicans), which are pathogenic for humans. The obtained results showed that pure TiO2 anatase is inactive against the tested strains, while the addition of ZnO to TiO2 improves noticeably the effectiveness of TiO2 nanoparticles, depending on the nature of the precursor of ZnO and the ZnO/TiO2 weight ratio.

Low‐density Polyethylene Films Loaded by Titanium Dioxide and Zinc Oxide Nanoparticles as a New Active Packaging System against Escherichia coli O157:H7 in Fresh Calf Minced Meat

Antibacterial packaging is introduced as a new method to prevent microbial food spoilage. Antibacterial effects of TiO2, ZnO and mixed TiO2–ZnO nanoparticle‐coated low‐density polyethylene (LDPE) films on Escherichia coli PTCC1330 were investigated. Bactericidal efficiency of 0.5%, 1% and 2% TiO2 and ZnO nanoparticles and also 1% mixed TiO2–ZnO nanoparticles with ratios of 25/75, 50/50 and 75/25 were tested under ultraviolet (UV) and fluorescent lights at two states: films alone and fresh calf minced meat packed. Maximum colony‐forming unit (CFU) reduction of 99.8% and 99.7% were obtained using 1% and 2% ZnO nanoparticle‐coated LDPE film under fluorescent light for films alone as well as 99.8% and 99.6% for fresh calf minced meat packed. 90.3% and 51.8% CFU reduction were recorded for 1% TiO2 nanoparticle‐coated LDPE films in the presence of UV light at direct contact with bacteria and fresh calf minced meat packed, respectively. Maximum CFU reductions of 96% and 64.1% were obtained using 50/50 ratio of TiO2/ZnO nanoparticles at the presence of UV light for film alone and fresh calf minced meat packed, respectively. ZnO nanoparticle‐coated LDPE films were identified as the best case to improve shelf life and prevent E. coli growth in fresh calf minced meat.

Preparation, Characterization and Comparative Study of Antibacterial Properties of Ag-TiO2 and ZnO-TiO2 Nanoparticles

هدیکچ مویناتیت دیسکا ) TiO2 ( هک تسا يداوم هلمج زا هب هلمج زا فلتخم صاوخ ندوب اراد تلع تسیز يراگزاـس ، تـمواقم نویـسادیسکا يوق صاوخ و یکیناکم اتبسن یتسیز فراصم رد بوخ کشزپ و ی تسا هتفای ناوارف دربراک . شیازـفا فدـه اـب هزورما راـک ا یی ،مویناـتیت دیـسکا رصانع اب هدام نیا شیلاآزا ي یم هدافتسا نهآ و يور ،هرقن دننام دوش . قـیرط زا يور و هرـقن زا هدافتسا اب مویناتیت دیسکا شیلاآ ،شهوژپ نیا رد دنیارف لس بیکرت تارذ ونان و دش ماجنا لژ تا هب دمآ تسد ه تفرگ رارق هسیاقم و یبایزرا دروم ، دن . يارـب زاـف ییاـسانش رد هدـش لیکـشت ياـه تابیکرت Ag-TiO2 و ZnO-TiO2 نومزآ زا فلتخم ياهامد رد دش هدافتسا سکیا يوترپ شارپ . مه نینچ يارـب هـصخشم وناـن یباـی زا تارذ فـیط یئرم ینورتکلا بذج یجنس شفنبارف ) UV-Vis ( کیا يوترپ يژرنا عیزوت ، س ) EDS ( ، ینادـیم لیسگ یشبور ینورتکلا پوکسورکیم ) FE-SEM ( و دش هدافتسا اتز لیسناتپ . ونان لایرتکاب یتنآ تیلاعف هسیاقم و یبایزرا زین تارذ دش . جیاتن هک داد ناشن ونان تارذ Ag-TiO2 و ZnO-TiO2 بیکرت اب راظتنا دروم هب لس شور لژ تیقفوم اب هتخاس دندش . یتنآ صاوخ یسررب هـک داد ناشن لایرتکاب بـیکرت Ag-TiO2 تـظلغ رد ياـه یگدـنرادزاب نییاپ ،رت تیلاعف ونان هب تبسن يرتلااب لایرتکاب یتنآ تارذ ZnO-TiO2 یم هئارا دهد .

Synthesis and characterization of ZnO–TiO2 nanopowders doped with fe via sol–gel method and their application in photocatalytic degradation of anionic surfactant

ZnO and 0, 5, and 10 mol % Fe-doped ZnO–TiO2 nanopowders were synthesized by the sol–gel Pechini method. The successful synthesis of coupled ZnO–TiO2 nanopowders was evident by XRD. Scanning electron microscopy (SEM) revealed that the Fe ions were well incorporated into the ZnO–TiO2 crystal lattice. The photocatalytic degradation of anionic surfactant (linear alkylbenzene sulfonate (LABS), was investigated in aqueous solution using ZnO and Fe-doped ZnO–TiO2 nanoparticles. The degradation was studied under different conditions such as the Fe3+ concentration, amount of photocatalyst, irradiation time, pH, initial concentration and presence of electron acceptor. The results showed that photocatalytic degradation of LABS was strongly influenced by these parameters. The best conditions for the photocatalytic degradation of LABS were obtained. It is found that under UV light irradiation, Fe-doping of ZnO–TiO2 increases the efficiency of its photocatalytic activity in degradation of LABS than pure ZnO and ZnO–TiO2.

Decomposition of chlorinated volatile organic compounds (CVOCs) using NTP coupled with TiO2/GAC, ZnO/GAC, and TiO2–ZnO/GAC in a plasma-assisted catalysis system

No study was found in the literature on the catalytic effect of TiO2/GAC (Granular activated carbon), ZnO/GAC, and TiO2-ZnO/GAC combined with non-thermal plasma (NTP) for the decomposition of chlorinated volatile organic compounds (CVOCs) in gas streams. In the present study, this catalytic NTP process was investigated to examine the effect of specific input energy (SIE), initial concentration, as well as residence time on the removal efficiency (RE) of CVOCs in a corona discharge reactor energized by a high frequency pulsed power supply. A dip-coating sol-gel impregnation technique was used to coat TiO2, ZnO, and mixture of TiO2-ZnO nanoparticles on GAC, which were then combined with NTP in a two-stage configuration. The results revealed that the efficacy of the catalysts was in the order TiO2-ZnO/GACâ� TiO2/GAC>ZnO/GAC with chloroform feeding, while when chlorobenzene introduced, the order changed to TiO2-ZnO/GAC > ZnO/GAC>TiO2/GAC. A significant enhancement was observed with RE as catalysts coupled with NTP in all cases and a RE of 100 was achieved in the presence of both TiO2/GAC and TiO2-ZnO/GAC at SIE of ca. 400JL-1. Considerable improvement was also noticed for coupling TiO2 and ZnO in both efficiency and catalyst life time. © 2014 Elsevier B.V.

Fabrication and Microstructure of ZnO-TiO<sub>2</sub> Composite Membranes by a Reverse Micelle and Sol-Gel Processing

ZnO-TiO2 nanoparticles were synthesized by a reverse micelle and sol-gel process. The average particle size of the colloid was below 30 nm and well dispersed in the solution. ZnOTiO2 composite membranes were fabricated by using the dip-coating method on a porous alumina support. ZnO-TiO2 composite membranes showed a crack-free microstructure and narrow particle size distribution even after the heat treatment up to 600°C. The average particle size of the membrane was 30-40nm, and the pore size of ZnO-TiO2 composite membrane was below 10 nm.