Pure TiO2 Nanoparticles Research Articles

Multi-antibiotics removal under UV-A light using sol-gel prepared TiO2: Central composite design, effect of persulfate addition and degradation pathway study

The removal of three antibiotics i.e., metronidazole (MNZ), ciprofloxacin (CIP) and tetracycline (TET), from aqueous system via TiO2 photocatalysis under UV-A light was investigated. Photocatalyst(s) were prepared using sol-gel method under different calcination temperatures (400–800 °C) and water-alcohol ratio. The spherical shaped catalyst (mean particle size ∼ 61 nm) was characterized via FTIR, XRD, BET, SEM, Raman, XPS, UV-DRS, and Fluorometry, and point of zero charge was also determined (pHPZC ∼ 6.6). Batch photo-catalytic degradation studies have shown complete degradation of MNZ, CIP and TET after 50, 75 and 20 min with a TOC removal of 37%, 44% and 31%, respectively. The activity of sol-gel prepared TiO2 was comparatively higher than commercially available pure anatase TiO2 nanoparticles due to lesser mean particle size. The ratio of water to alcohol in the preparation of TiO2 catalyst was found to have significant effect on antibiotic removal. Moreover, persulfate (PS) addition of 0.1 g/L amplified the pseudo-first-order removal-rate constant by 2.75, 3.3 and 1.6 times for MNZ, CIP and TET, respectively. The higher initial pH values (8 and 10) have shown the best removal efficiency for all antibiotics. Subsequently, central composite design (CCD) experiments were conducted under multi-antibiotic conditions. Near complete removal of all antibiotics were observed within 120 min. Scavenging studies revealed that hydroxyl and superoxide radicals play major roles in photo-catalytic degradation of MNZ, CIP and TET. During photocatalysis, MNZ degradation was initiated by hydroxylation reaction, CIP by piperazine ring opening by hydroxyl attack and TET by multiple hydroxylation process. Overall, TiO2 showed good efficiency at degrading multiple antibiotics and has the potential for practical application on a larger scale.

Visible and Solar Light Degradation of Ciprofloxacin and Norfloxacin using Titania Nanocomposite

A simple sol-gel approach was used to synthesize TiO2 nanoparticles and its composite TiO2-PEG (TPG) using polyethylene glycol (PEG). The synthesized samples were characterized by XRD, SEM -EDX, TEM, UV-DRS, photoluminescence, Raman, XPS and BET-surface area techniques. The development of non-toxic, cost-effective, biocompatible and efficient polymeric nanocomposite increases the mechanical, thermophysical and physico-chemical properties of prepared nanomaterials. PEG affected the reaction with the crystallization process of the prepared titania nanoparticles to a great extent. The antibiotics ciprofloxacin and norfloxacin of fluoroquinolone class are widely used to treat certain bacterial infections and at the same time their residues generate serious health issues due to the lack of proper waste water treatment systems thus causing environmental pollution. The present study is thus focused on synthesizing efficient titania PEG nanocomposite to enhance the photocatalytic degradation of antibiotics in both solar and visible light. Efficiency of degradation was achieved maximum upto 74% with TPG and 64% with pure TiO2 nanoparticles for ciprofloxacin in visible light, similarly the degradation of norfloxacin was achieved 65% with TPG and 57% with TiO2 nanoparticles. Sunlight irradiation resulted in the degradation of ciprofloxacin to 80.2% with TPG and 77% with TiO2 nanoparticles whereas it was 78.7% with TPG and 68.6% with TiO2 nanoparticles for the degradation of norfloxacin. These results indicate that the catalyst TPG showed higher activity in presence of solar and visible light than TiO2 nanoparticles. Recyclability was also studied showing the stability of the photocatalyst used even after five successive runs.

Structural, optical and magnetic studies of sol-gel synthesized Mg-doped pure anatase TiO2 nanoparticles for spintronic and optoelectronics applications

Here in we reported the synthesis of MgxT1−xO2 (for x = 0.00, 0.01, 0.02, 0.03, 0.04) nanoparticles via simple sol-gel technique. Mg-doped TiO2 is a hopeful material for the study of the origin of room-temperature ferromagnetism (RTFM) in dilute magnetic semiconductors (DMS) systems, but very scanty work on this material has been reported. The as-synthesized samples were subjected to X-ray diffraction (XRD) which shows that the samples aligned with tetragonal anatase phase of TiO2. UV\\Vis\\NIR diffuse reflectance spectroscopy analysis showed a slight increase in TiO2 energy band gap with Mg doping from 3.25eV to 3.33 eV as a result of blue shift in absorbance edge of the sample. The obtained recombination of photo-generated electrons and holes is excellently curbed by Mg doping which was examined by the photoluminescence study and the blue shift in the most intense Eg (3) Raman mode confirms integrated Mg in TiO2 lattice. As revealed by Field Emission Scanning Electron Microscopy (FESEM), the morphology of the samples showed irregularly distributed nanoparticles and to examine elemental composition of the samples, Energy Dispersive X-ray (EDX) were carried out which stipulates all elements like Ti and Mg are in the sample. Soft ferromagnetism at low magnetic field with hysteresis loop was noticed in all the samples, with values of coercivity in the range 206–309Oe. Maximum value of saturation magnetization was evident by the 2% doped sample. These materials can find applications in electronics, spintronics and magneto-optics devices.

Facile synthesis and enhanced acetone sensing properties of ZnO/TiO2 nanocomposite at room temperature

This paper reports a clear outline of the synthesis and gas-sensing characteristics of pure ZnO, TiO2 nanoparticles (NPs) and ZnO/TiO2 (ZT) nanocomposite (NC) for acetone detection at room temperature for diabetes screening. Thesamples were synthesized using an uncomplicated low-cost co-precipitation method. The ZT nanocomposites have shown a combined phase structure of ZnO (wurtzite) and TiO2 (anatase) from X-ray diffraction. The absorbance of the samples was analyzed by UV–Vis Spectrophotometer and a variation in the optical bandgap is studied.A high-performance ZT NC gas sensor is successfully realized for excellent selectivity, and quick response-recovery towards acetone detection. The sensing mechanism is ascribed to the composition, morphology, and enhanced oxygen adsorptionsites revealing better performances than the pure ZnO and TiO2 NPs. The ZT NC of composition ZnO (0.60 at.%):TiO2 (0.40 at.%) is observed to enhance the acetonegas detection signal for the lowest sub micro level ppb concentration of 100 ppb (parts per billion) in comparison to the pure ZnO and TiO2 nanoparticles. A superior response time (τres) of 13 s and recovery time (τrec) of 11 s are observed for ZT-1 sample with a high sensitivity response of 179 % is studied and therefore the nanocomposite material can be successfully utilized for acetone biomarker in diabetes.

Experimental investigations on preparation of silica coated TiO2 nanoparticles (S-TiO2) and its mechanical characterizations as reinforcement in polylactic acid (PLA)/thermoplastic polyurethane (TPU) composites

Polymer composites exhibit unique properties that make them ideal for an extended range of industrial and engineering fields. However, the mechanical characteristics of polymer composites play a crucial role in assessing their applicability for specific load-bearing applications, and their failure mechanisms are largely influenced by these characteristics. This study examines the mechanical characteristics of Polylactic acid (PLA)/Thermoplastic polyurethane (TPU) polymer composites reinforced with silica-coated TiO2 nanoparticles(S-TiO2). The Sol-gel method was employed to coat nanoparticles with silica, to enhance their surface properties and functionalization, as well as to mitigate the photo-degradation of pure TiO2 nanoparticles. Morphology and micro structure of nano particles were evaluated by transmission electron microscopy (TEM), Energy-dispersive x-ray spectroscopy (EDS), Fourier-Transform Infrared Spectroscopy (FTIR) and x-ray diffraction (XRD). The PLA/TPU pellets were blended at 70/30 ratio and then reinforced with S-TiO2 at weight percentages ranging from 0.5% to 2.0%, in increments of 0.5%. SEM images have shown the existence and uniform distribution of TPU and S-TiO2 in PLA. The mechanical properties of fabricated polymer composites such as hardness, tensile strength, elongation at break, flexural strength, and impact strength were determined using various mechanical tests. Thermal behaviour of polymer composite was analysed by using Thermogravimetric Analysis (TGA). It was found that polymer composite containing 2% by weight of S-TiO2 exhibited an increase in hardness, tensile strength, and flexural strength by 10.3%, 23.2%, and 20%, respectively.

TiO2-CuO heterojunction nanoparticles synthesized by green chemistry supported on beach sand granules: Optical, morphological and structural characterization

This research has studied the optical, morphological/textural and structural properties of pulverized TiO2-CuO heterostructures and their immobilization on chemically purified beach sand granules to evaluate the potential of these materials for wastewater treatment. The preparation of TiO2-CuO heterojunctions was developed by the ultrasound-assisted wet impregnation method in the presence of PEG-400. For this methodology, the TiO2 and CuO nanoparticles were first synthesized by green chemistry using Moringa (Moringa Oleifera) leaves aqueous extract and an ultrasound bath. Then, the metal oxide nanoparticles were calcinated and immobilized on etched sand granules via immersion in a coating suspension. All materials were characterized by UV–Vis DRS, photoluminescence (PL), SEM-EDS, HRTEM-SAED, BET area, Raman spectroscopy, XRD and XPS. Optical characterization revealed that the CuO incorporation favors light adsorption in the visible spectrum and reduces the band gap energy from 3.14 to 1.28 eV. Morphological studies showed that the pulverized materials are agglomerated with an affinity for the high porosity regions of the beach sand granules. Also, TiO2-CuO heterojunctions exhibited a broader size distribution (15.81 ± 7.45 nm) than pure TiO2 nanoparticles (10.38 ± 1.24 nm). The structural analysis confirmed that the pure TiO2 and CuO nanoparticles are formed exclusively in the anatase and tenorite phases. At the same time, the heterostructures’ process preparation favors the partial transition from CuO to Cu2O. Finally, the purified sand support is mainly based on α-Quartz (trigonal); the as-prepared material is a potentially versatile and reusable candidate for pollutant photodegradation under UV or visible light sources.

Effect of MgO recombination barrier layer on the performance of monolithic-structured solid-state dye sensitized solar cells

ABSTRACT In this paper, the optical, structural and electrical properties of pure and magnesium-doped TiO2 nanoparticles (NPs) of different cycles (2, 4, 6 and 8 cycles) were explored systematically. The magnesium-doped TiO2 was synthesised through successive ionic layer adsorption and reaction (SILAR) and deployed into dye sensitised solar cells. The effects of the MgO barrier layer was evaluated . The results show enhanced optical properties with MgO coating with a diminished band gap energy. The X-ray diffraction studies show that the anatase phase was preserved after doping and the dopant does not change the crystalline phase of the TiO2. The SEM results show well-dispersed morphology. For the device with 4 SILAR cycles of MgO, gains in open-circuit voltage, current density and simultaneous increase in efficiency were observed which is attributed to improved charge collection efficiency as electrons diffusing through TiO2 have a better chance of reaching the electrode before recombining. At greater SILAR cycles (6 and 8), losses in photocurrent caused net decrease in efficiencies. The results presented in this report implies that the modification of TiO2 with a metal oxide (MgO) can result to good photon management.

Production of the protein-based nitrogen-doped carbon quantum dots/TiO2 nanoparticles with rapid and efficient photocatalytic degradation of hexavalent chromium

Hexavalent chromium (Cr (VI)) is a typical heavy metal ion caused numerous wastewater, and the photocatalysis is an attractive advanced treatment process for Cr (VI) removal. Biomass material bovine serum albumin and tetrabutyl titanate were used to prepare nitrogen-doped carbon quantum dots and TiO2 (N-CQDs/TiO2) nanoparticles by a facile one-step hydrothermal method. The excellent photonic conversion function of N-CQDs narrowed band gap widths of TiO2 to 2.84 eV due to the N element and the CQDs introduced to the TiO2 successfully. When the mass ratio of BSA and TiO2 was 1 and the hydrothermal reaction time was 48 h, the obtained nanoparticle can rapidly and efficiently degrade of Cr (VI) in 40 min of reaction, and the kinetic reaction rate reached 10.7 times that of pure TiO2 nanoparticles. And the Cr (VI) was reduced in 10 min by 1 mg/L nanoparticle under the pH of 2 or tartaric acid content of 1 g/L due to the electrons were transferred from N-CQDs to the TiO2 surface to achieve effective electron/hole separation and reacted with the Cr (VI) to reduce it to Cr (III). The N-CQDs/TiO2 also exhibited degradation of Congo red completely and killing of E. coli under simulated solar light.

Improved photocatalytic degradation of methylene blue under visible light using acrylic nanocomposite contained silane grafted nano TiO2

Removal of organic dyes from wastewater by photocatalytic oxidation (PCO) under visible light has attracted attention of many scientists. In this research, TiO2 nanoparticles were surface modified by aminopropyltriethoxysilane (APTES) at different concentrations (1, 3, 5, 7, and 10 wt%). The nanoparticles were applied to acrylic latex at 1, 3, and 5 wt% to prepare photocatalytic nanocomposite paints. The modified nanoparticles were evaluated for photocatalytic degradation of methylene blue in an aqueous solution as model-polluted wastewater. The modified nanoparticles showed 30, 29, and 22% enhancement in photocatalytic degradation of methylene blue compared to the pure TiO2 nanoparticles under UV, visible and solar lights, respectively. Using the modified nanoparticles in the acrylic film caused 31.6 and 56.3% improvement in the tensile strength and toughness compared to the pure nanoparticles containing sample. The modified nanoparticles considerably enhanced the light absorbance capacity of the acrylic paint. On this basis, the modified paints (at 3 wt% loading of nanoparticles) showed 29, 27, and 20% improvements in discoloration of methylene blue stain compared to the pure nano TiO2 containing nanocomposite under UV, visible, and solar lights, respectively.

Preparation and characterization of rare earth element nanoparticles for enhanced photocatalytic degradation

The present work focuses on the photocatalytic degradation of methylene blue (MB) on erbium ion (Er3+) doped TiO2 under visible light. Pure TiO2 nanoparticles and erbium (Er3+) doped TiO2 nanocomposite (Er3+/TiO2) NCs were synthesized using the sol–gel method. The synthesized (Er3+/TiO2) NCs were characterized using Fourier transform infrared spectroscopy (FTIR), high resolution scanning electron microscopy (HR-SEM), elementary dispersive X-ray (EDX), X-ray diffraction (XRD), and X-ray photoelectron spectra (XPS), specific surface area (BET), zeta potential, and particle size. Different parameters were used to study their efficiency for the photoreactor (PR) and the synthesized catalyst. These parameters include pH of the feed solution, the rate of flow, the presence of an oxidizing agent (aeration pump), different ratios of nanoparticles, the amount of catalyst, and the concentrations of pollutants. An example of an organic contaminant was the dye methylene blue (MB). The result achieved using the synthesized nanoparticles (I) under ultraviolet light pure TiO2 was found to have degraded by 85%. For (Er3+/TiO2) NCs under visible light, dye removal increased with pH to a maximum of 77% degradation at pH 5. Furthermore, photocatalytic efficiency improves to 80% at 40 rpm (3 l/h) low motor speed. The degradation efficiency decreased to 70% when the MB concentration was increased from 5 to 30 mg/L. When oxygen content was increased using an air pump, and deterioration reached 85% under visible light, it improved performance.

Zeolite Y-supported carbon-doped TiO2 nanocomposites: Efficient solar photocatalysts for the purification of medicinal wastewater

The existence of antibiotics in aquatic streams destroys water quality and thereby poses serious ecological hitches. Photocatalysis involving nanosemiconductors is an environmentally benign technique for the mineralization of antibiotics. Herein, we prepared a new visible light-sensitive photocatalyst, zeolite Y-supported carbon-doped TiO2 nanocomposite (zeolite Y-c-TiO2), for the elimination of cefazolin antibiotic in wastewater systems. The structural and optical properties of the synthesized nanocomposites were investigated by Fourier transform infrared spectroscopy (FT-IR), powder X-ray diffraction analysis (XRD), scanning electron microscopy (SEM), energy-dispersive X-ray analysis (EDX), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), and Brunauer-Emmett-Teller surface area analysis (BET) as well as diffuse reflectance spectroscopy (UV-DRS) and photoluminescence spectroscopy (PL). The UV-Vis absorbance spectrum of zeolite Y-c-TiO2 exhibited a red shift towards longer wavelength with an increase in visible light absorption as compared to pure TiO2 nanoparticles and zeolite Y-supported TiO2 nanocomposites (zeolite Y-TiO2). Accordingly, the photocatalytic action of the zeolite Y-c-TiO2 for the degradation of methylene blue was evaluated under solar simulator, and it turned out to be highly efficient (100%) mineralization as compared to TiO2-nanoparticles (42%) and zeolite Y-TiO2 (62%) after 70 min irradiation for a 50mg L-1 methylene blue solution. Radical scavenging experiments revealed the involvement of hydroxyl radicals, superoxide radicals, and photogenerated holes in the degradation process. Consequently, zeolite Y-c-TiO2 was applied for the photocatalytic degradation of the cefazolin antibiotic in water, and complete degradation of cefazolin (50 mg L-1) was observed within 6 h of solar light irradiation on zeolite Y-c-TiO2. The degradation pathway of cefazolin was proposed by considering various intermediates detected via LC-MS analysis. The study points to the significant potential of zeolite Y-c-TiO2 photocatalyst for the purification of medicinal wastewater under sunlight.

MRC-5 Human Lung Fibroblasts Alleviate the Genotoxic Effect of Fe-N Co-Doped Titanium Dioxide Nanoparticles through an OGG1/2-Dependent Reparatory Mechanism

The current study was focused on the potential of pure P25 TiO2 nanoparticles (NPs) and Fe(1%)-N co-doped P25 TiO2 NPs to induce cyto- and genotoxic effects in MRC-5 human pulmonary fibroblasts. The oxidative lesions of P25 NPs were reflected in the amount of 8-hydroxydeoxyguanosine accumulated in DNA and the lysosomal damage produced, but iron-doping partially suppressed these effects. However, neither P25 nor Fe(1%)-N co-doped P25 NPs had such a serious effect of inducing DNA fragmentation or activating apoptosis signaling. Moreover, oxo-guanine glycosylase 1/2, a key enzyme of the base excision repair mechanism, was overexpressed in response to the oxidative DNA deterioration induced by P25 and P25-Fe(1%)-N NPs.

Investigation on interfacial properties of conventional and functional modified TiO2/water nanofluids

The interfacial properties of conventional and functional modified nanofluids, including tension and contact angle, are investigated experimentally. The conventional nanofluids are prepared by mixing pure TiO2 nanoparticles into water containing surfactants, and the functional modified nanofluids are prepared by adding 3-aminpropyltriethoxysilane (APTS) or γ-glycidoxypropyltrimethoxysilane (GPTMS) treated nanoparticles into water. The results show that the surface tension of both conventional and functional modified nanofluids shows a decreasing trend with the elevating nanoparticle concentration and temperature. The surface roughness of copper plates as well as the nanoparticle loading would both have obvious effects on the contact angle. The surface tension and contact angle of conventional nanofluids decrease with the increasing surfactant concentration. Among all tested samples, the APTS modified nanofluids have larger surface tension and contact angle, which indicates a poorer wettability. The sodium dodecyl sulfate (SDS) added nanofluids have better wettability, in which smaller surface tension and contact angle are found.

Synergetic adsorption-photocatalysis process of titania-silica photocatalysts and their immobilization on PEEK nonwoven filter for VOC removal

Studying the synergistic mechanisms of removing volatile organic compounds (VOCs) in an adsorption-photocatalytic oxidation process, remains a major challenge. This study explores the synergistic effects of SiO2 nanoparticles and anatase TiO2 nanocomposites in removing ethyl acetate, as a VOC test model, under solar irradiation in a photo-reactor. The physiochemical properties of the synthesized TiO2/SiO2 nanocomposites (70/30 and 50/50, molar ratio) and pure TiO2 nanoparticles were systematically characterized. It was found that the TiO2/SiO2 nanocomposite with 30% SiO2 showed the best synergistic adsorption and photocatalytic activity for the elimination of ethyl acetate among the tested samples. The integrated adsorption-photocatalytic mechanisms of TiO2/SiO2 nanocomposites were revealed by inverse gas chromatography (IGC), electron paramagnetic resonance (EPR), photoluminescence (PL) techniques and kinetic analysis. Moreover, a facile ambient-temperature immobilization method was successfully developed to load photocatalysts onto poly-ether ether-ketone (PEEK) nonwoven. In addition, the photo-induced chemiluminescence (PICL) analysis confirmed that the TiO2/SiO2 coating prevented the photodegradation of PEEK substrate under UVA radiation and improved its photostability. These results provided new understanding on designing highly adsorptive photocatalysts which are commercially applicable on filter materials for efficient VOC removal and air purification.

Nanowires-Assembled TiO2 Nanorods Anchored on Multilayer Graphene for High-Performance Anodes of Lithium-Ion Batteries.

Multilayer graphene (MLG) prepared via ultrasonic exfoliation has many advantages such as its low-cost and defect-free nature, high electronic conductivity, and large specific surface area, which make it an apt conductive substrate for TiO2 composites. To synthesize graphene/TiO2 hybrids, traditional methods that greatly depend on the chemical bond of oxygen-containing functional groups on graphene with titanium cations are not applicable due to the absence of these functional groups on MLG. In this work, a facile chemical method is developed to directly deposit TiO2 on the MLG surface without the introduction of chemically active groups. With this method, four types of TiO2 materials, that is pure anatase TiO2 nanoparticles, a mixture of anatase TiO2 nanoparticles and rutile TiO2 nanoflowers, pure rutile TiO2 nanoflowers, and pure rutile TiO2 nanorods, are homogeneously anchored on the MLG surface by controlling the amount of HCl in the reactant. Interestingly, the rutile TiO2 nanorods in the TiO2/MLG composite are assembled by many TiO2 nanowires with an ultra-small diameter and ultra-long length, which provides a better synergetic effect for high performances as LIB anodes than other composites. A specific capacity of 631.4 mAh g−1 after 100 cycles at a current density of 100 mA g−1 is delivered, indicating it to be a valuable LIB anode material with low cost and high electrochemical performances.

Structural, Optical, and Arsenic Removal Properties of Sol-Gel Synthesized Fe-Doped TiO2 Nanoparticles.

Pure and Fe-doped TiO2 nanoparticles were synthesized by the sol–gel method. The samples were characterized by X-ray diffraction, Raman spectroscopy, BET, UV-vis diffuse reflectance spectroscopy, and scanning electron microscopy. The results show a dependence between the crystallite size and the amount of dopant, which decreases from 13.02 to 12.81 nm. The same behavior was observed in the optical properties, where the band gap decreased from 3.2 to 2.86 eV. The arsenic (V) adsorption was tested in aqueous solution containing 5 mg/L of arsenic and 0.5 g/L of adsorbent at pH 7 and in dark conditions. The results indicate that the TiO2-B sample shows a higher arsenic removal, reaching 88% arsenic removal from the water at pH 7. Thus, it is also shown that the best performance occurs at pH 5, where it reaches an arsenic removal of 94%. Ion competition studies show that arsenic removal capacity is slightly affected by chloride, carbonate, nitrate, and sulfate ions. According to the results, the synthesized samples are a promising material for treating arsenic-contaminated water.

MoS2/Ag/TiO2 for photoanode of dye sensitized solar cells

In this paper, we demonstrate the application of a novel ternary nanocomposite MoS2/Ag/TiO2 photoanode in high efficiency plasma dye sensitive solar cell (PDSSC). Ternary nanocomposites MoS2/Ag/TiO2 was successfully synthesized by a simple solvothermal method without any hazardous substances. In order to achieve higher photoelectric conversion efficiency of DSSC, the photoanode’s ability of capturing light and electron transfer rates needs to be improved. Ag provides a power for light capture, while MoS2 inhibits electron–hole recombination and promotes electron transport in the ternary nano-composite MoS2/Ag/TiO2. The nanocomposite was characterized by scanning electron microscope and transmission electronmicroscope, which indicated that the MoS2/Ag/TiO2 was synthesized. Due to local surface plasmon resonance (LSPR), silver nanoparticles were doped onto TiO2 nanoparticles, which greatly improved the optical parameters. The synthesis of Ag nanoparticles and MoS2 was confirmed by X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). The performance of dye sensitive solar cell (DSSC) composed of ternary nano-composite material MoS2/Ag/TiO2 was tested, the photoelectric conversion efficiency (PCE) reaches 9.3%, which is 26% higher than that of pure TiO2 nanoparticle photoanode.

Synthesis and Characterization of N-Modified TiO2 for Efficient Removal of Rhodamine B Dye under Natural Sun Irradiation

In this work, Nitrogen modified TiO2 nanoparticles were successfully synthesized via fast acid catalyzed sol-gel route with ammonia solution as a primary nitrogen precursor. The effect of amount of nitrogen was investigated by further incorporating secondary nitrogen in prepared sample with urea precursor by adopting wet impregnation approach. Pure TiO2 nanoparticles were also synthesized for comparison. Prepared photo-catalysts were characterized by Fourier-Transform Infrared spectroscopy, X-Ray diffraction and diffuse reflectance spectroscopic analysis. XRD results confirmed the formation of anatase crystalline phase for all prepared samples. Laboratory test experiments on Rhodamine B (RhB) decomposition under artificial visible light (20W White LED) revealed the highest photocatalytic activity of catalyst doubly doped with ammonia solution and urea whereas pure TiO2 showed poor activity under visible light illumination. The effect of operational parameters such as catalyst dose, solution pH and substrate concentration on photocatalytic efficiency was also evaluated to obtain optimal conditions. Photocatalysis of RhB under natural sunlight with doubly-doped photo-catalyst (T5N2) showed remarkable photocatalytic performance of 99.9% after 1 hour illumination.

Synthesis of the high durability photocatalytic materials with tertiary components

The high durability, re-collectable and low-cost materials with tertiary (reduced graphene-TiO2-Fe3O4, denoted as GrTiFe) components for degradation of toxic organic compounds have been prepared from different precursors by coprecipitation and hydrothermal methods. By this procedure, TiO2 and Fe3O4 nanoparticles have been growing on the reduced graphene oxide. The as-synthesized nanocomposites have been characterized with X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), scanning electron microscope and magnetic hysteresis, and studied on the photo-degradation reaction of Moderacid Black (MDB). The result shows that the photocatalytic activity of as-synthesized composites is much higher than that of pure TiO2 nanoparticles and the composites can be easily collected from water using a magnet for reusing. In addition, the GrTiFe is also able to degrade the organic compounds under modeling sunlight radiation.

Investigation of Morphological, Elemental, Structural, and Optical Properties of Fe-Doped TiO2 Nanoparticles

In this research, Fe-doped TiO2 nanoparticles were synthesized by sol-gel technique followed by annealing at 450 oC in a vacuum. The effects of Fe-doping on the morphological, elemental, structural and optical properties of TiO2 nanoparticles have been investigated. XRD analysis was performed to examine the structural properties of synthesized pure TiO2 nanoparticles and Fe-doped TiO2 nanoparticles. Surface analysis was done using Scanning Electron Microscopy. Optical properties were determined using UV/Vis spectroscopy. Morphological analysis revealed that TiO2 nanoparticles have a spherical shape. EDX analysis confirmed the elemental composition of Fe-doped TiO2 nanoparticles. XRD patterns showed that diffraction peaks can be attributed to TiO2 with the anatase phase.