Co-doped TiO2 Nanomaterials Research Articles

Influence of calcination temperature on the microstructure and photocatalysis performance of B/Sm-TiO2 nanomaterials

In this work, we fabricated boron/samarium co-doped TiO2 nanomaterials (B/Sm-TiO2) by a sol-gel method. The effects of calcination temperature on the crystal texture, grain size, and photocatalytic characteristics were investigated by XRD, XPS, SEM, TEM, and UV–vis DRS. Using the Materials Studio software and density functional theory, the band structures and state densities of TiO2 single or codoped B and Sm ions have been determined. The photocatalytic degradation of methyl orange under visible light was used to evaluate the photocatalytic performance of B/Sm-TiO2 nanomaterials. The results demonstrate that the photocatalytic performance of B/Sm-TiO2 nanomaterials is significantly affected by different calcination temperatures. With the increase of calcination temperature, the size of TiO2 particles increases, and the TiO2 phase changes from anatase to rutile with a crystalline transition temperature of 700 °C. The visible light absorption of B/Sm-TiO2 under the forging condition of 600 °C is enhanced accordingly, the degradation efficiency is improved, and the degradation rate of methyl orange reaches 89% after 60 min of light irradiation.

Biogenic surfactant mediated facile synthesis of visible light sensitized Zn/Mg co-doped TiO2 nanomaterials – a green approach: evaluation of photocatalytic activity by degradation of Amido Black 10B

Visible light-driven Zn and Mg co-doped TiO2 nanomaterials were synthesized by varying dopant concentrations in presence of biogenic surfactant Sapindus emerginatus (biogenic extract) via the Sol-gel method and have been successfully applicated to the degradation of Amido Black 10B (AB 10B), an exemplary anionic textile azo dye pollutant. This study explored the potent capping properties of biogenic extract surfactant by encapsulating the Zn/Mg co-doped TiO2. In a view to assessing the physical and optical properties of the as-synthesized catalysts, various advanced instrumental techniques were adopted. The Transmission Electron Microscopy and Scanning Electron Microscopy analysis show the formation of small particle sizes (6.9 nm) pertaining to biogenic surfactant-assisted Zn/Mg co-doped TiO2 (ZMT4S2). The substitutional doping of Zn and Mg into the TiO2 framework by substituting Ti4+ ion and the encapsulation of surfactant around catalyst was confirmed by Fourier Transform-Infrared Spectroscopy (FTIR) spectral studies. The surface area of the ZMT4S2 was found to be high (195 m2 g− 1) as compared with undoped TiO2 (74 m2 g− 1) and Zn (1.00 wt%) / Mg (0.25 wt%) co-doped TiO2 (ZMT4) (132 m2 g− 1). The red shift in the absorbance was observed for all the catalysts analyzed using UV-Vis-Diffuse Reflectance Spectroscopy (UV-Vis-DRS) confirms the ZMT4S2 showing less band gap of 2.1 eV than other catalysts. Further the electrical property of the catalyst was studied using Electrochemical Impedance Spectroscopy. The results obtained from impedance and Mott-Schotky plots show the reduced electrical resistance and electron hole recombination respectively. The sensitivity of the catalyst towards visible light was confirmed by its band gap energy measurement using UV-Vis-DRS. The anatase phase of all the catalysts was confirmed using powder X-ray diffraction. The composition and wt% of dopants revealed the Energy Dispersive X-ray spectra agree well with the calculated value. The slightly shifted frequency bands (FTIR) further confirmed the doping of Zn and Mg. The characterization analysis reports further accounts for the effective degradation of AB 10B dye (99%) taking place within 20 min of irradiation time at optimized reaction parameters such as best dopant concentration ZMT4, catalyst dosage (100 mg L− 1), dye concentration (10 mg L− 1) and solution pH 3.

UV–Visible Light Driven Photocatalytic Degradation of Ciprofloxacin by N,S Co-doped TiO2: The Effect of Operational Parameters

Photocatalytic degradation using TiO2 is one of the most effective techniques for treating residual emerging compounds present in water. However, practical applications are limited since it only absorbs ultraviolet irradiation. Nitrogen and sulfur (N, S) co-doped TiO2 nanomaterials (N,S-TiO2) were prepared by a controlled sol–gel method; the characterization and photocatalytic activity have been studied for the removal of ciprofloxacin antibiotic under UV–Visible light. The interstitial doping of nitrogen and sulfur substitute oxygen and titanium into the TiO2 lattice, which increases the valence band and decreases the conduction band, respectively. The lowest value band-gap of 2.5 eV and the crystallite size of 5.13 nm compared to other available synthesis methods was observed on N,S-TiO2 which allowed to broaden the light absorption to the visible region. The low level electron and hole recombination was related by the N, S doping. The optimal ciprofloxacin removal was obtained at pH 5.5, a dosage of 0.05 g, initial concentration of 30 mg L−1 with a removal efficiency of 78.7%. A comparison of the effectiveness of antibiotic treatment of N,S-TiO2 with synthetic TiO2 and commercial TiO2 was also made, taking the potential for regeneration into account. The photocatalytic degradation of ciprofloxacin catalyzed by N,S-TiO2 was described by pseudo-first-order kinetics.

A systemic study on Gd, Fe and N co-doped TiO2 nanomaterials for enhanced photocatalytic activity under visible light irradiation

In this study, the gadolinium (Gd), iron (Fe), and nitrogen (N) doped TiO2 nanomaterials have been synthesized by a sol–gel method with slight modification. While the effect of Gd on the crystalline morphology, specific surface area, chemical composition, and bandgap of the doped samples have been investigated by SEM, TEM, BET, XRD, UV–vis, and XPS. The bonds of Ti–O–Gd, N–Ti–O, and O–N–Ti induced by Gd and N substitution inside the TiO2 crystal lattice structure have been investigated by XPS. The UV–vis spectra showed that the absorption edges of all doped samples are significantly red-shifted, further extending towards the visible spectrum, owing to the impurity band formation of the above valence band (VB) by doping of N. With the increase in the Gd doping amount, the photocatalytic efficiency of GFNTO (tri-doped samples) followed the sequence: G2.0FNTO > G2.5FNTO > G3.0FNTO > G1.5FNTO > G3.5FNTO > G1.0FNTO. The first-order reaction constant of G2.0FNTO for photodegradation of methylene blue (MB) is ten times higher than that of un-doped TiO2. The significant improvement in the performance of the co-doped sample is due to the finer particle size, larger specific surface area, narrowed bandgap, more defect sites, and oxygen vacancies induced by the substitution of Ti4+ by N, Fe3+, and Gd3+. The recycling experiment showed that the photocatalytic efficiency of G2.0FNTO can still reach 95% after its five cycles, further exhibiting the excellent stability and re-usability.

Zn–F co-doped TiO2 nanomaterials: Synthesis, structure and photocatalytic activity

Zn–F co-doped TiO2 nanomaterials were prepared by the sol-gel method. The effect of various amounts of modifying additives (0.1–2 mol% Zn and 0.1–4 mol% F) and calcined temperature (500–900 °C) on the properties of the obtained materials were studied. X-ray diffraction, transmission electron microscopy, scanning electron microscopy, UV–Vis spectroscopy, fluorescence, and EDX spectroscopy were used to analyze the crystal structure, surface morphology, elemental composition, and stability of the prepared nanomaterials. The introduction of ions was found to increase the thermal stability of anatase modification of titanium dioxide. The photocatalytic activity of obtained materials was studied in the reaction of a model pollutant photodegradation under UV and visible light activation. The photocatalytic activity induced by UV exposure is higher than that of commercial material Degussa P25. It was shown that the best photocatalytic activity exhibit materials with minimum amounts of modifying additives (0.1 mol% of Zn and F).

Sol-Gel Synthesized N and Mn Co-Doped TiO2 Nanomaterial for Photocatalytic Degradation of Malathion under Visible Light Irradiation

Different weight percentages (0.25-1.00 wt%) of Nitrogen (Non-Metal) and Manganese (Metal) co-doped nano titania were synthesized by sol-gel method and characterized by XRD, UV-vis.DRS, FT-IR, XPS, SEM and TEM. The XRD results has shown that all the prepared catalysts are in anatase phase indicating that co-doping of N and Mn did not affect the crystal structure of TiO2. From the UV-vis.DRS spectra a significant absorption shift towards visible region was noticed in N and Mn co-doped TiO2 and their presence was confirmed by XPS and FT-IR results. SEM and TEM results showed spherical nanoparticles with average particle size of 9 nm. Photocatalytic efficiency of synthesized nano materials was tested on non-biodegradable organophosphorous pesticide, Malathion under visible light irradiation. The effect of dopant concentration, pH, catalyst dosage, and initial pesticide concentration on photocatalytic degradation of malathion was studied and optimum conditions were established. Among the synthesized samples 0.50 wt% N & 1.00 wt% Mn-TiO2 exhibited best photocatalytic performance. Photoluminiscent spectroscopy (PL) was used to examine the rate of production of oxidative species, hydroxyl radicals which play key role in photocatalytic degradation.

Synthesis of Fe- and Co-Doped TiO2 with Improved Photocatalytic Activity Under Visible Irradiation Toward Carbamazepine Degradation.

Pure TiO2 and Fe- and Co-doped TiO2 nanoparticles (NPs) as photocatalysts were synthesized using wet chemical methods (sol-gel + precipitation). Their crystalline structure and optical properties were analyzed using X-ray diffraction (XRD), Raman spectroscopy and Fourier-transform infrared (FTIR) spectroscopy, ultraviolet-visible light (UV-Vis) diffuse reflectance spectroscopy (DRS), and photoluminescence (PL) spectroscopy. The photocatalytic activity of the synthesized nanoparticles was evaluated through degradation of carbamazepine (CBZ) under UV-A and visible-light irradiations. The XRD and Raman analyses revealed that all synthesized nanomaterials showed only the anatase phase. The DRS results showed that the absorption edge was blue-shifted for Fe-doped TiO2 NPs. The decrease in charge recombination was evidenced from the PL investigation for both Co-doped and Fe-doped TiO2 nanomaterials. An enhancement in photocatalytic degradation of carbamazepine in aqueous suspension under both UV-A light and visible-light irradiations was observed for Fe-doped Titania NPs by comparison with pure TiO2. These results suggest that the doping cations could suppress the electron/hole recombination. Therefore, the photocatalytic activity of TiO2-based nanomaterials was enhanced.

Preparation and Photocatalytic Properties of Ce/g-C3N4 Co-doped TiO2 Nanomaterials

A Ce/TiO2/g-C3N4 composite material was prepared by sol-gel method using g-C3N4 as support and Ce(NH4)2(NO3)6 as dopant. The structural and morphological characterization of the samples was detected by TEM, XRD, FTIR, UV-Vis. RhB was selected as the target pollutant, the photocatalytic and renewable properties of the samples driven by visible light were evaluated. The results showed that Ce/TiO2/g-C3N4 had excellent heterojunction structure. The ternary components cooperate with each other to show excellent photocatalytic performance for RhB solution with molar concentration of 0.5×10−5mol·L−1 under the condition of dosage of 20.0mg, pH 5.0 and visible light-driven 180min. The degradation rate of RhB was 99.3% better than that of g-C3N4, TiO2 and Ce/TiO2. Cyclic degradation experiments indicated that the Ce/TiO2/g-C3N4 had high photocatalysis stability and reusability. Active group capture experiments revealed that ·O2- was the main active species in the photocatalytic degradation of RhB over Ce/TiO2/g-C3N4, and the corresponding contribution rate of ·O2- was 84.1%.

Study on Structural and Optical Properties of Ni and Mn Codoped TiO2 Nanomaterials and Its Application in Visible Light Photocatalytic Activity of Indigo Caramine Dye

Study on Structural and Optical Properties of Ni and Mn Codoped TiO2 Nanomaterials and Its Application in Visible Light Photocatalytic Activity of Indigo Caramine Dye

Synthesis and Characterization of Copper and Boron Codoped TiO2 Nanomaterials for the Photocatalytic Degradation of Methyl Orange Dye

Synthesis and Characterization of Copper and Boron Codoped TiO2 Nanomaterials for the Photocatalytic Degradation of Methyl Orange Dye

Structure, photocatalytic and antibacterial activity study of Meso porous Ni and S co-doped TiO2 nano material under visible light irradiation

Abstract Undoped and Ni–S co-doped mesoporous TiO2 nano materials were synthesized by using sol–gel method. The characteristic features of as prepared catalyst samples were investigated using various advanced spectroscopic and analytical techniques. The characterization results of the samples revealed that all the samples exhibited anatase phase (XRD), decreasing band gap (2.68 eV) (UV–Vis-DRS), small particle size (9.2 nm) (TEM), high surface area (142.156 m2·g−1) (BET), particles with spherical shape and smooth morphology (SEM); there is a frequency shift observed for co-doped sample (FT-IR) and the elemental composition electronic states and position of the doped elements (Ni and S) in the TiO2 lattice analyzed by XPS and EDX. These results supported the photocatalytic degradation of Bismarck Brown Red (BBR) achieved with in 110 min and also exhibited the antibacterial activity on Staphylococcus aureus (MTCC-3160), Pseudomonas fluorescence (MTCC-1688) under visible light irradiation.

Visible light driven mesoporous Mn and S co-doped TiO2 nano material: Characterization and applications in photocatalytic degradation of indigocarmine dye and antibacterial activity

The present study explored the Photocatalytic & antibacterial activity of Mesoporous Mn and S co-doped TiO2 nano material synthesized by sol-gel method. As prepared samples were characterized by X-ray diffraction (XRD), X-ray photo electron spectroscopy (XPS), Scanning electron microscopy (SEM), Energy dispersive X-ray Spectroscopy (EDX), Fourier transform infrared spectroscopy (FT-IR), UV–vis Diffused Reflectance Spectroscopy (UV–vis-DRS), Transmission electron Microscopy (TEM), Brunauer-Emmett-Teller (BET) and Photoluminescence (PL). The Characterization results revealed that all the co-doped and undoped samples shows anatase phase. The Frequency shift of Ti-O-Ti in the catalyst samples was observed in FT-IR due to substitutional doping of Mn and S by replacing Ti and O, Further the catalyst shows smooth spherically shaped small particle size (7.6 nm) with high surface area (155.87 m2/g) and having less band gap energy (2.58 eV). The most reactive •OH are produced during the progress of reaction was determined by using Photo luminescence (PL) technique. The photocatalytic efficiency and antibacterial activity was evaluated by degradation of Indigo carmine(IC), Bacillus coagulans and klebsiella pneumonia respectively. The complete degradation of IC was achieved at optimum reaction parameters such as 0.150 g of the catalyst dosage, solution pH = 4 and initial dye concentration 20 ppm with the catalyst of 1.0 Wt% of Mn-0.25 Wt% of S co-doped Titania with in 90 min. The zone of inhibition bacterial growth was observed (24 mm and 23 mm) compared to control value (Chloramphenicol) 25 mm and 24 mm.

Preparation and characterization of Sn/La co-doped TiO2 nanomaterials and their phase transformation and photocatalytic activity

The pure, tin (Sn)-doped, lanthanum (La)-doped and Sn/La co-doped titanium dioxide (TiO2) nanomaterials were synthesized using sol-gel method followed by calcination at the temperature of 360 °C, 450 °C and 600 °C, respectively. The structures of the nanomaterials were characterized by X-ray diffraction (XRD), Thermogravimetric (TG), Differential Thermal Analysis (DTA), Scanning Electron Microscopy (SEM), Energy Dispersive Spectrum (EDS), Transmission Electron Microscopy (TEM), X-ray Photoelectron Spectrum (XPS), Diffuse Reflectance Spectrum (DRS), Photoluminescence Spectrum (PL), Brunauer-Emmett-Teller Measurements (BET), respectively. The photocatalytic property of the photocatalysts under UV light was evaluated through the degradation of Rhodamine B (RhB). The results show that the anatase-rutile phase transition is promoted by Sn-doping while La-doping retards the phase transition. However, La doping plays a major role in the process of phase transformation. The photocatalytic activity of pure TiO2 is affected by annealing temperature remarkably and the optimal annealing temperature is 450 °C. The photocatalytic activity of TiO2 is enhanced significantly by Sn and La doping at three different temperatures. Sn/La-TiO2 exhibits the highest degradation rates and the fastest reaction rates probably owing to the synergistic effect of Sn4+ and La3+ ions in inhibiting the recombination of photogenerated electron-hole pairs. The formation of extra surface hydroxyl groups and additional surface area are also beneficial for the photocatalytic activity.

Enhanced electrochemical performance of porous Co-doped TiO2 nanomaterials prepared by a solvothermal method

Abstract Highly porous nanostructures having large specific surface areas are very desirable for electrochemical supercapacitors to achieve a large energy storage capacity. We synthesized porous Co-doped TiO2 nanostructures with an average diameter of 450 nm through a simple solvothermal method by using tetrabutyl titanate and cobalt acetate as precursors and polystyrene beads as templates. The optimized 7% Co-doped TiO2 nanostructures-based supercapacitor electrodes exhibited a specific capacitance of 352 F g-1 at a current density of 0.5 A g−1 while retaining a capacity of 97.2% after 3000 cycles. This excellent electrochemical performance may be ascribed to the synergistic effects originating from conductivity enhancement of TiO2 through optimized Co-doping and larger specific surface areas rendered by structural porosity, when compared to the undoped TiO2 samples. Our results suggest that porous Co-doped TiO2 nanostructures can be explored for potential electrochemical applications.

Fabrication of visible light driven nano structured Copper, Boron codoped TiO2 for photocatalytic removal of Lissamine Green B

In the present research work a potentially improved Copper (Cu) and Boron (B) codoped TiO2 nano materials were synthesized by varying the different dopant concentrations (Copper 0.25, 0.50, 0.75, 1 wt% and Boron 0.25, 0.50, 0.75, 1 wt%) using solgel method for the photocatalytic degradation of Lissamine Green B. In order to investigate the physical, chemical and optical properties of a catalyst, which play a key role in its photocatalytic activity, as prepared samples were characterized by various instrumental techniques. The crystalline phase study performed for all the samples using X-ray powder diffraction (XRD) confirmed the formation of anatase TiO2. Chemical composition of the prepared catalyst investigated by X-ray photo electron spectroscopy (XPS) affirmed the presence of constituent elements (Ti, O, Cu & B) on the catalyst surface. The surface microstructure studied by field emission scanning electron microscopy (FE-SEM) revealed that the TiO2 particles having spherical shape with rough surface morphology. The average particle size and surface area of the catalyst determined by high-resolution transmission electron microscopy (HRTEM) and Brunauer-Emmett-Teller (BET) surface area analyser, revealed that the codoped catalyst shows a high percentage of small particles of size 6.8 nm and a high surface area of 135.6 m2/g, respectively. The band edge absorption shift of the samples was determined by diffuse reflectance spectroscopy analysis (DRS) and the results exhibited that among all the codoped samples Copper 0.25 wt% and Boron 1 wt% (CBT1) catalyst shows a reduced band gap energy of 2.73 eV. The characterization results supported the photocatalytic activity of the catalyst for the degradation of Lissamine Green B within 90 min at the optimum reaction parameters such as dopant concentration of Cu at 0.25 wt% & B at 1 wt%, pH = 3, catalyst dosage 0.075 g/L and dye concentration 10 mg/L under visible light irradiation. The mechanism of enhanced photocatalytic performance of the catalyst was proposed by the results obtained from the PL spectra and main reactive species trapping measurements.

Synergistic Effects of Phosphorus and Cobalt Binary Doping on Visible Light Activity of TiO2 by Sol-Gel Method and Evaluation of Photocatalytic Efficiency

Phosphorus and cobalt codoped TiO2 nanomaterial was successfully prepared by single step sol-gel method by doping different weight percentages of dopants concentrations into TiO2 lattice. The co-doped TiO2 samples were characterized to confirm the structural and morphological changes in TiO2 crystal lattice by using X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray (EDX), transmission electron microscopy (TEM), UV-visible diffuse reflectance spectroscopy (UV-vis. DRS), X-ray photo electron spectroscopy (XPS), Brunauer-Emmmett-Teller surface area analyzer (BET) and Fourier transform infrared spectroscopy (FT-IR). The characterization results revealed that all the codoped samples show anatase phase, nanoparticle (5.8 nm) and narrow band gap (2.54 eV). These results enhance the photocatylytic activity of codoped TiO2 in visible light for the degradation of Fast Green dye within 60 min.

Photochemical quenching of aqueous methylene blue by N, Nb co-doped TiO2 nanomaterials under visible light: a confirmatory UV/LC-MS study

Nanodimensional un-doped, Nb doped, N doped and N,Nb co-doped TiO2 particles have been prepared by the sol-gel procedure. Phase identification of the anatase particles was done by X-ray powder diffraction and Deby–Scherrer calculations revealed their particle sizes to range from 20 to 30 nm. The band gap energies of the samples were measured by UV–Vis-diffuse reflectance (UV-DRS) spectra. While un-doped TiO2 showed wide optical absorption in the UV region. The co-doped TiO2 particles exhibited narrow band gaps of ~2.7 eV, which showed absorption in the visible region. A decline in charge carrier recombination rates in the prepared samples was confirmed through photoluminescence (PL). The morphological appearances of the particles have been examined by scanning electron microscopy. X-ray photoelectron spectroscopy (XPS) of the samples confirmed the incorporations of N and Nb into the TiO2 matrices. The photocatalytic efficiencies of the prepared particles have been determined by the degradation of the non-biodegradable dye methylene blue (MB) under electromagnetic radiation. The co-doped sample showed superior photocatalytic activity under the visible light (λ > 400) over the other samples. Photochemical quenching of aqueous MB was further analysed by UV/LC-MS which confirmed the attenuation of methylene blue.

Effect of calcination temperature on the microstructure and antimicrobial activity of boron and cerium co-doped titania nanomaterials

The photocatalytic antimicrobial activities of B and Ce co-doped TiO2 nanomaterials calcinated at different temperatures under visible-light illumination were investigated. B/Ce–TiO2 nanomaterials were characterised by X-ray diffraction (XRD), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS) and UV-Vis absorption spectrum (DRS) Photocatalytic antimicrobial activities of the nanomaterials were determined by the inhibition zone and shaking-flask method against Escherichia coli and Staphylococcus aureus. Results show that the phase of B/Ce–TiO2 could be transformed from amorphous to anatase and then to rutile by increasing the calcination temperature. At lower calcination temperature, B/Ce–TiO2 nanomaterials exhibit smaller crystal size and higher specific surface area. The present forms of B ions were a substitution B occupying O sites, interstitial B atoms and B–O–B bonds. Ce3+ and Ce4+ co-existed in the materials. Results of the antimicrobial experiment under visible-light irradiation show that B/Ce–TiO2 nanomaterials exhibited enhanced antimicrobial activities. Ultimately, the action mechanism of B/Ce–TiO2 was discussed.

Synthesis, characterization and visible light photocatalytic activity of Mg2+ and Zr4+ co-doped TiO2 nanomaterial for degradation of methylene blue

Mg2+ and Zr4+ co-doped TiO2 was synthesized by sol–gel method. Catalysts were characterized by XRD, UV–vis DRS, SEM-EDX, TEM, BET, XPS and FT-IR to evaluate the crystal patterns and crystallite size (5.07–18.9 nm), bandgap energy, morphology, surface area, surface composition with oxidation states and incorporation of dopants into TiO2 lattice. Degradation of methylene blue was carried out under visible light irradiation by varying the reaction parameters such as initial dye concentration, catalyst loading and pH of the solution. 1.0 wt% Mg2+ and 0.25 wt% Zr4+ codoped TiO2 was found to be an efficient catalyst.

Assembly of CdS nanoparticles on boron and fluoride co-doped TiO2 nanofilm for solar energy conversion applications

Boron and fluoride co-doped TiO2 nanomaterial is successfully synthetized using a facile process, followed by chemical bath deposition in an organic solution to ensure high wettability and superior penetration ability of the B/F co-doped TiO2 films.