Experimental analysis and optimization of the synthesizing property of nitrogen‐modified TiO2 visible‐light photocatalysts

BACKGROUND: The aim of this study was to investigate improvement of the photocatalytic activity of visible‐light driven nitrogen‐modified TiO₂ (N‐TiO₂) powder toward methyl blue (MB) and direct blue‐86 (DB‐86) dyes. The Taguchi method with an L₉ orthogonal array was applied to plan the synthesis parameters, i.e. nitrogen sources, nitrogen source concentrations, stirring time and calcined temperatures. 95% confirmation experiments were undertaken to verify the effectiveness of the Taguchi method. RESULTS: All N‐TiO₂ photocatalysts were shifted toward the visible light region with the optical band gap (Eg). Nitrogen source concentrations were significant parameters for the photocatalytic decolorization rate constants (k values). In comparison with pure TiO₂, the photodecolorization behavior of N‐TiO₂ toward DB‐86 was superior with a reaction rate constant of 1.68 × 10^?3 min^?1, and a 4 h photodecolorization efficiency of 34%. CONCLUSION: The Taguchi method was reported to alter the surface properties of commercial Degussa P25 TiO₂, which could then be used as a visible‐light driven photocatalyst. The visible‐light‐driven photocatalyst was investigated to determine material characteristics. Greater photodecolorization of MB and DB‐86 dye pollutants using optimally‐prepared N‐TiO₂ under visible light irradiation was successfully obtained. Copyright © 2011 Society of Chemical Industry     

Enhanced the photocatalytic activity of B–C–N–TiO2 under visible light:Synergistic effect of element doping and Z-scheme interface heterojunction constructed with Ag nanoparticles

In order to enhance the photocatalytic activity of TiO₂ under visible light, Ag nanoparticles were introduced into tridoped B–C–N–TiO₂ (TT) catalyst by photoreduction deposition. Ag/B–C–N–TiO₂ (ATT) catalysts with the functions of reducing band gap and carrier recombination were prepared. At the same time, the effect of the amount of Ag on the photocatalytic performance of ATT catalyst was investigated. Through XRD, XPS, PL and other characterization methods, the (211)/(101)/Ag interface heterojunction mechanism similar to the traditional Z-scheme heterojunction was proposed. The intervention of Ag nanoparticles changed the P–N interface heterojunction between (211)/(101) to the (211)/(101)/Ag Z-scheme interface heterojunction. The results show that ATT catalyst exhibits the highest photocatalytic activity when the molar amount of Ag is 0.005% with the MB degradation rate of the ATT catalyst (0.01707 min^?1), which is 14.59 times of TiO₂ (0.00117 min^?1) and 2.02 times of TT (0.00847 min^?1). In addition, the four cycles efficiencies of ATT for MB degradation were all above 94.00%.This study reveals the possibility of construction of Z-scheme heterojunctions between precious metal nanoparticles and different interfaces of TiO₂, and provides a reference for the construction of Z-scheme interface heterojunctions.     

The construction of TiO2 NTs/Ag3PO4–AgBr by SILAR deposition as promising photocatalysts for hydrogen production and pollutant treatment

The construction of ternary TiO₂ NTs/Ag₃PO₄–AgBr photocatalysts was carried out by the SILAR deposition of Ag₃PO₄ and AgBr on TiO₂ nanotube arrays (TiO₂ NTs) for enhancing the photocatalytic application in H₂ evolution and dyeing wastewater remediation. The adjustment of Ag₃PO₄/AgBr deposition cycles was used to optimize the optical absorption and photocatalytic property. The TiO₂ NTs/Ag₃PO₄–AgBr (5) prepared with 5 cycle deposition of Ag₃PO₄ and AgBr exhibited the optimal photoelectric activity and photocatalytic performances. The photocatalytic rate constants for the degradation of MO, RhB and MB dyes achieved 1.35 × 10⁻², 3.30 × 10⁻² and 4.47 × 10⁻² min⁻¹, respectively, and the visible light-driven photocatalytic H₂ evolution rate achieves 46.87 μmol cm⁻² h⁻¹. •O₂⁻ radicals exhibited the key influence on the organic dye degradation, and the as-prepared photocatalysts showed exceedingly high photocatalytic activity and stability. Furthermore, the photocatalytic mechanism was proposed based on the ESR result.     

Characterizations of TiO2/SiO2/Ni–Cu–Zn Ferrite Composite for Magnetic Photocatalysts

The TiO₂/SiO₂/Ni–Cu–Zn ferrite composite for magnetic photocatalysts with high photocatalytic activity is successfully prepared in this study. The composite are composed of spherical or elliptical Ni–Cu–Zn ferrite nanoparticles about 20–60 nm as magnetic cores, silica as barrier layers with thickness of 15 nm between the magnetic cores and titania shells with thickness approximately 1.5 nm. Photodegradation examination of TiO₂/SiO₂/ Ni–Cu–Zn ferrite composite was carried out in methylene blue (MB) solutions illuminated under a Xe arc lamp with 35 W and color temperature of 6000 K. The results indicated that about 47.1% of MB molecules adsorbed on the TiO₂/SiO₂/Ni–Cu–Zn ferrite composite within 30 min mixing due to it higher pore volume of 0.034 cm³/g, and after 6 h Xe lamp irradiation, 83.9% of MB 16.1% was photodegraded. Compared with the TiO₂ /Ni–Cu–Zn ferrite composite, the TiO₂/SiO₂/Ni–Cu–Zn ferrite composite with silica barrier layer prohibited the photodissolution and enhanced the photocatalytic ability. The magnetic photocatalyst shows high photocatalytic efficiency that the apparent first‐order rate constant k_obs is 0.18427 h^?1, and good magnetic property that the saturation magnetization (M_s) of is 37.45 emu/g, suggesting the magnetic photocatalyst can be easily recovered by the application of an external magnetic field.     

Photocatalytic Oxidation of Organic Micro-Pollutants: Pilot Plant Investigation and Mechanistic Aspects of the Degradation Reaction

An innovative pilot plant based on UVB and TiO₂ (Anatase) allowed for photocatalytic degradation of organic micro-pollutants. The catalyst was immobilized onto a channel through which the solution containing a target molecule (methylene blue, MB) was re-circulated. Due to the cationic nature of the MB substrate, the adsorption reaction onto the catalyst surface provided a significant contribution to the overall degradation mechanism due to the negatively charged surface at neutral pH (TiO₂ pH_zpc = 6.8). The influence of the initial MB concentration was investigated in the range 0.3–2.0 mg L^?1 with the Langmuir–Hinshelwood (LH) model showing good data correlations at concentrations up to 0.7 mg L^?1, whereas at higher concentrations a pure zero-order (catalytic) kinetic trend was observed. Flow rate of the re-circulating solution sensibly influenced kinetics after the larger volumes of liquid exposed to UVB/TiO₂ and to the better oxygen saturation in the liquid phase. UV?vis and HPLC-MS/MS experimental determinations allowed for identification of MB residual concentration and by-products.     

Synthesis of TiO2−xNy/Ag‐PbMoO4 Composite and Their Photocatalytic Activity Under Simulated Solar Light Irradiation

TiO_2?xN_y/Ag‐PbMoO₄ composite were synthesized by sonochemical method. The results revealed that the band‐gap energy absorption edge of TiO_2?xN_y/Ag‐PbMoO₄ composite was shifted to a longer wavelength as compared to TiO₂, TiO_2?xN_y, PbMoO_4, and Ag‐PbMoO₄. The TiO_2?xN_y/Ag‐PbMoO₄ composite showed the enhanced photocatalytic activity for degradation of indigo carmine dye (ICD) under simulated solar light irradiation. The TiO_2?xN_y/Ag‐PbMoO₄ composite exhibited the highest percentage (95.4%) of degradation of ICD and the highest reaction rate constant (0.0244 min^?1) in 2 h. The results suggested that a good combination of Ag and TiO_2?xN_y nanoparticles has great influence on the photocatalytic behavior of PbMoO₄.     

Preparation of a hydroxyethyl–titanium dioxide–carboxymethyl cellulose hydrogel cage and its effect on the removal of methylene blue

A novel TiO₂ hydrogel cage model was built for the removal of methylene blue (MB), an organic pollutant. This TiO₂ hydrogel cage was prepared with the biomass materials of hydroxyethyl cellulose (HEC) and carboxymethyl cellulose (CMC), and this hydrogel cage structure was characterized by scanning electron microscopy, transmission electron microscopy, and X‐ray diffraction. The contents of the encased TiO₂ and its swelling properties with different CMC proportions of this hydrogel cage were studied to obtain a suitable crosslinking network structure and optimal synthesis conditions. Compared to an equivalent amount of pure TiO₂, the much higher removal efficiency of MB with our prepared TiO₂ hydrogel cage was attributed to the synergistic effect of the photocatalytic degradation for TiO₂ and the adsorption enrichment for cellulose hydrogels. Furthermore, the adsorption kinetics of the intraparticle diffusion model were used to study the adsorption enrichment process of the TiO₂ hydrogel cage. In addition, on the basis of the results of photocatalytic degradation and recycling experiments, excellent performances with respect to self‐cleaning, regenerative ability, and easy recovery, were shown for this HEC–TiO₂–CMC cage material, which demonstrated ideal application potential for MB removal. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 44925.     

Novel chitosan‐TiO2 nanohybrid: Preparation,characterization, antibacterial,and photocatalytic properties

In this report, chitosan (CS) encapsulated titanium dioxide (TiO₂) nanohybrid was prepared by chemical precipitation method. Fourier transform infrared spectroscopy (FT‐IR) and X‐ray diffraction (XRD) confirmed the formation of nanohybrid. Transmission electron microscopy (TEM) analysis showed the immobilization of TiO₂ nanoparticles on the surface of CS. The nanohybrid was also characterized by thermogravimetric analysis (TGA) and zeta potential. The nanohybrid exhibited high photocatalytic activity as evident from the degradation of methylene blue (MB) dye. The result revealed substantial degradation of the MB dye (90%) under UV‐light illumination. The catalytic efficiency was unaltered even after five cycles of reuse. In addition, the nanohybrid exhibited a superior antibacterial activity of 100% within 24 h of treatment against Escherichia coli (E. coli) was measured by colony forming units (CFU). POLYM. COMPOS., 35:327–333, 2014. © 2013 Society of Plastics Engineers     

Photodegradation of four fluoroquinolone compounds by titanium dioxide under simulated solar light irradiation

BACKGROUND; In this study, simultaneous photocatalytic degradation of four fluoroquinolone (FQ) compounds (i.e. ofloxacin, norfloxacin, ciprofloxacin and enrofloxacin) was investigated in TiO₂ suspensions under simulated solar light irradiation. Effects of experimental variables including pH, TiO₂ dosage, initial substrate concentration and hydrogen peroxide (H₂O₂) on the degradation processes were also investigated. RESULTS: The antibiotics degradation was pH‐influenced. The photocatalytic reaction followed the pseudo‐first‐order model, with reaction rate constants (k) 0.026, 0.027, 0.022 and 0.026 min^?1 for ofloxacin, norfloxacin, ciprofloxacin and enrofloxacin, respectively. Complete elimination of four FQs was achieved in a reaction system composed of 0.5 g L^?1 of TiO₂ and 82.5 mg L^?1 of H₂O₂ at pH 6 after 90 min irradiation. Mineralization of FQs during TiO₂ photocatalysis was slower than the FQs conversion, and the antibacterial activity of the four FQs was completely removed by TiO₂ under simulated solar light irradiation. CONCLUSION: The four FQs can be simultaneously degraded and mineralized with commercially available TiO₂ under simulated solar light irradiation. Microbiological analysis showed that the antibacterial activity of the four FQs was completely removed. These results are helpful for antibiotics removal in the environment, and for exploring new technology for wastewater treatment. Copyright © 2012 Society of Chemical Industry     

Preparation of titanium dioxide/tungsten disulfide composite photocatalysts with enhanced photocatalytic activity under visible light

Titanium dioxide/tungsten disulfide (TiO₂/WS₂) composite photocatalysts were fabricated via a one-step hydrothermal synthesis process, using TiCl₄ as titanium source and bulk WS₂ as sensitizer. The morphology, structure, specific surface area and optical absorption properties of the composite photocatalysts were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), X-ray powder diffraction (XRD), specific surface area analyzer and ultraviolet-visible diffuse reflection spectrum (UV-vis DRS), respectively. The photocatalytic activity of as-prepared photocatalysts was evaluated by the degradation of methyl orange (MO) under illumination of 500W Xenon lamp. The results indicated that TiO₂/WS₂ composite photocatalysts possessed excellent photocatalytic activity, and ～95% of the degradation rate for MO was reached when molar ratio of WS₂ to TiO₂ was 0.004 and the irradiation time was 60 min. Moreover, the carrier trapping experiment and fluorescence spectra showed that ·O ₂ ^? was the key component in the photocatalytic degradation process and O₂ was reduced to be ·O ₂ ^? by the electrons from the conduction band of TiO₂ and WS₂ for the degradation of MO.     

Preparation and characterization of spindle-shaped nanoporous anatase TiO<Subscript>2</Subscript>–Ag<Subscript>3</Subscript>PO<Subscript>4</Subscript> heterostructure with enhanced visible light driven photocatalytic performance

A novel spindle-shaped nanoporous anatase TiO₂–Ag₃PO₄ heterostructure with high photocatalytic activity was successfully prepared by a simple method. The Ag₃PO₄ nanoparticles with a diameter of 20–50 nm were deposited on the surface of the spindle-shaped TiO₂. The effect of Ag₃PO₄ nanoparticles amounts on the photocatalytic activity was investigated. The results showed that the TiO₂–Ag₃PO₄ composite with the mass ratio of TiO₂:Ag₃PO₄ = 1:2 displayed the highest photodegradation efficiency of methylene blue (MB) and Bisphenol A (BPA), which was more highly than that of Ag₃PO₄ nanoparticles and also indicated a high stability of photocatalytic degradation. The improved activity of the TiO₂–Ag₃PO₄ composite could be attributed to the efficient separation of the photogenerated electron–hole pairs.     

Microwave photocatalysis III. Transition metal ion‐doped TiO2 thin films on mercury electrodeless discharge lamps: preparation,characterization and their effect on the photocatalytic degradation of mono‐chloroacetic acid and Rhodamine B

BACKGROUND: Mercury electrodeless discharge lamps (Hg‐EDLs) were used to generate UV radiation when exposed to a microwave field. EDLs were coated with doped TiO₂ in the form of thin films containing transition metal ions Mⁿ⁺ (M = Fe, Co, Ni, V, Cr, Mn, Zr, Ag). Photocatalytic degradation of mono‐chloroacetic acid (MCAA) to HCl, CO₂, and H₂O, and decomposition of Rhodamine B on the thin films were investigated in detail. RESULTS: Polycrystalline thin doped TiO₂ films were prepared by dip‐coating of EDL via a sol–gel method using titanium n‐butoxide, acetylacetone, and a transition metal acetylacetonate. The films were characterized by Raman spectroscopy, UV/Vis absorption spectroscopy, X‐ray photoelectron spectroscopy (XPS), electron microprobe analysis and by atomic force microscopy (AFM). The photocatalytic activity of doped TiO₂ films was monitored in the decomposition of Rhodamine B in water. Compared with the pure TiO₂ film, the UV/Vis spectra of V, Zr and Ag‐doped TiO₂ showed significant absorption in the visible region, and hence the photocatalytic degradation of MCAA had increased. The best apparent degradation rate constant (0.0125 min^?1), which was higher than that on the pure TiO₂ film by a factor of 1.7, was obtained with the Ag(3%)/TiO₂ photocatalyst. The effect of doping level of vanadium acetylacetonate on the photocatalytic efficiency of the V‐doped TiO₂ was determined. CONCLUSIONS: Transition metal ion‐doped TiO₂ thin films showed significant absorption in the visible region. The metal doped TiO₂ photocatalyst (with an appropriate amount of V, Zr and Ag) on the Hg‐EDLs increased the degradation efficiency of MCAA in a microwave field. Copyright © 2009 Society of Chemical Industry     

Carbon-based TiO2-x heterostructure nanocomposites for enhanced photocatalytic degradation of dye molecules

Application of brown titanium dioxide (TiO_2-x) and its modified composite forms in the photocatalytic decomposition of organic pollutants in the environment is a promising way to provide solutions for environmental redemption. Herein, we report the synthesis of effective and stable TiO_2-x nanoparticles with g-C₃N₄, RGO, and multiwalled carbon nanotubes (CNTs) using a simple hydrothermal method. Among all the as-synthesized samples, excellent photocatalytic degradation activity was observed for RGO-TiO_2-x nanocomposite with high rate constants of 0.075 min^?1_, 0.083 min^?1 and 0.093 min^?1 for methylene blue, rhodamine-B, and rosebengal dyes under UV–Visible light irradiation, respectively. The altered bandgap (1.8 eV) and the large surface area of RGO-TiO_2-x nanocomposite impacts on both absorption of visible light and efficiency of photogenerated charge electron (e^?)/hole (h⁺) pair separation. This resulted in enhanced photocatalytic property of carbon-based TiO_2-x nanocomposites. A systematic study on the influence of different carbon nanostructures on the photocatalytic activity of brown TiO_2-x is carried out.     

Crosslinked hydroxyl‐conductive copolymer/silica composite membranes based on addition‐type polynorbornene for alkaline anion exchange membrane fuel cell applications

Crosslinked hydroxyl‐conductive copolymer/silica composite membranes based on addition‐type polynorbornene, poly(dodoxymethylene norbornene‐co‐norbornene‐3‐(trimethylpropyl ammonium)‐functionalized silica (QP(DNB/NB‐SiO₂), were prepared by a sol–gel method. Copolymer composite membranes with different degree of quaternary ammonium functional silica, designated as QP(DNB/NB‐SiO₂‐X) (X = 5, 10, 15 and 25 wt%, respectively), displayed good dimensional stabilities with low in‐plane swelling rate of 1.32–3.7%, good mechanical properties with high elastic modulus of 605.4–756.8 MPa and high tensile strength of 13.2–20 Mpa. The achieved copolymer composite membranes could self‐assemble into a microphase‐separated morphology with randomly oriented long‐range aliphatic chain/cylinder ionic channels that were imbedded in the hydrophobic PNB matrix. Among these membranes, the QP(DNB/NB‐SiO₂‐25) showed the parameter with ionic conductivity of 9.33 × 10^?3S cm^?1, methanol permeability of 2.89 × 10^?7cm² s^?1, and ion‐exchange capacity(IEC) of 1.19 × 10^?3 mol g^?1. A current density of 82.3mA cm^?2, the open circuit voltage of 0.65 V and a peek power density of 32 mW cm^?2 were obtained. POLYM. ENG. SCI., 58:13–21, 2018. © 2017 Society of Plastics Engineers     

Photoelectrocatalytic humic acid degradation kinetics and effect of pH,applied potential and inorganic ions

This study addresses the removal of humic acid (HA) dissolved in an aqueous medium by a photoelectrocatalytic process. UV₂₅₄ removal and the degradation of color (Vis₄₀₀) followed pseudo‐first order kinetics. Rate constants were 1.1 × 10^?1 min^?1, 8.3 × 10^?2 min^?1 and 2.49 × 10^?2 min^?1 (R² > 0.97) for UV₂₅₄ degradation and 1.7 × 10^?1 min^?1, 6.5 × 10^?2 min^?1 and 2.0 × 10^?2 min^?1 for color removal from 5 mg dm^?3, 10 mg dm^?3 and 25 mg dm^?3 HA respectively. Following a 2 h irradiation time, 96% of the color, 98% of the humic acid and 85% of the total organic carbon (TOC) was removed from an initial 25 mg dm^?3 HA solution in the photoanode cell. Photocatalytic removal on the same photoanode was also studied in order to compare the two methods of degradation. Results showed that the photoelectrocatalytic method was much more effective than the photocatalytic method especially at high pH values and with respect to UV₂₅₄ removal. The effect of other important reaction variables, eg pH, external potential and electrolyte concentration, on the photoelectrocatalytic HA degradation was also studied. Copyright © 2003 Society of Chemical Industry     

Enhanced photocatalytic activity of highly transparent superhydrophilic doped TiO2 thin films for improving the self-cleaning property of solar panel covers

Undoped and metal doped nanocrystalline TiO₂ transparent thin films were synthesized on glass substrates via sol-gel/dip-coating method. TiO₂ thin film coatings can be applied to the surfaces of solar panels to impart self-cleaning properties to them. The structural and optical properties of few nanometer-thick films were characterized by XRD, SEM, CA, AFM, XPS, and UV–Vis spectrophotometry techniques. The stoichiometric TiO₂ films crystallized in anatase phase, with a particle size of ～100 nm, which were uniformly distributed on the surface. The prepared films with a roughness of ～1–5 nm, increased the hydrophilicity of the glass surface. Reducing the amount of Ti precursor (X) favored the improvement of film quality. To improve the photocatalytic activity of the TiO₂ thin film, it was doped with Ni, Cd, Mo, Bi and Sr metal ions. The effect of metal doping on the photocatalytic activity of the films was investigated using the degradation process of methylene blue (MB) dye as the model contaminant. Among the prepared coatings, the Sr–TiO₂ film showed the highest efficiency for MB degradation. It increased the dye degradation efficiency of the films under both UV and Vis lights. The kinetic investigations also showed that the degradation of MB by TiO₂ and M ? TiO₂ films obeyed the pseudo-first order kinetics.     

Comparison on photocatalytic degradation of gaseous formaldehyde by TiO2, ZnO and their composite

In order to compare the photocatalytic properties of TiO₂, ZnO and their composite in the gas phase pollutant environment, nanocomposite with different mole ratios of TiO₂/ZnO were designed to degrade gaseous formaldehyde. The results showed that the rate constant of TiO₂ for formaldehyde degradation was 0.05 min^?1 which was two orders of magnitude larger than that of ZnO in our experiment. Through comprehensive analysis of UV–vis diffuse reflectance (UV–vis) spectra, photoluminescence spectra (PL) and energy band diagram, it was found that the differences of photocatalytic properties between ZnO and TiO₂ may mainly originate from the increased recombination of photoinduced charges in ZnO. The photocatalytic properties of TiO₂/ZnO composite for formaldehyde degradation were much worse than those of TiO₂, while better than those of ZnO. The addition of a small amount of ZnO weakened the photocatalytic properties of TiO₂. It may be attributed to that the recombination action of photoinduced electron–hole pairs in ZnO.     

Methylene blue adsorption from aqueous solutions to flexible poly(vinyl chloride) silica composites

Methylene blue (MB) adsorption studies were performed with poly(vinyl chloride)‐(dioctyl phthalate)‐silica composites, which were obtained by using plastisol‐plastigel technology. The films were flexible, having elastic modulus of 1.0–1.5 GPa. Diminishing MB concentration in the aqueous phase was followed as the adsorption process advanced by using visible spectroscopy. Contributions of the individual components of the composites to adsorption were also investigated. Although the MB adsorption capacity was extensively high for silica, it was moderate for the composite, most likely owing to the occlusion of pores of silica by plasticizer to some extent. The improvement of MB adsorption capacity of the composites as the silica ratio increased was explicitly deduced from the optical microscopy photographs. The diffusion coefficients of MB through the composites were 5 × 10^?13, 6 × 10^?13, and 3 × 10^?13 m² s^?1 with regression coefficients of 0.73, 0.89, and 0.88 for 0, 2, and 16% silica‐containing composites, respectively. Because of the slow diffusion of MB in poly(vinyl chloride)‐silica composites, using them as dynamic column adsorbent was not practical. However, these versatile plastics can be used as plastic labels, colored clothing, leather substitutes, antimicrobial medical devices, and laser printable surfaces. J. VINYL ADDIT. TECHNOL., 21:42–50, 2015. © 2014 Society of Plastics Engineers     

The comparative study of photocatalytic self‐cleaning properties of synthesized nanoscale titania and zirconia onto polyacrylonitrile fibers

The photocatalytic activity of TiO₂ and ZrO₂‐coated polyacrylonitrile (PAN) fibers was compared through the self‐cleaning of methylene blue and eosin yellowish. TiO₂ and ZrO₂ nanocrystals were successfully synthesized and deposited onto PAN fibers with photocatalytic self‐cleaning activity using the sol‐gel process at low temperature. The pristine and treated samples have been characterized by several techniques, such as scanning electron microscopy, transmission electron microscopy, Fourier transform infrared spectroscopy, diffuse reflectance spectroscopy, X‐ray diffraction, and thermogravimetric analysis. The TiO₂ nanoparticles with 10–20 nm in size, and ZrO₂ with 20–40 nm have been synthesized to form dispersed particles on the fiber surface, which shows photocatalytic properties when exposed to UV–Vis light. The photocatalytic activity, tested by measuring the degradation of adsorbed methylene blue and Eosin Y. Photocatalytic activity of TiO₂‐coated fibers toward dyes degradation was higher than that of ZrO₂‐coated fibers. This preparation technique can be also applied to new fabrics to create self‐cleaning and UV irradiation protection properties in them. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Regulating Photocatalytic Selectivity of Anatase TiO2 with {101}, {001}, and {111} Facets

In this work, we demonstrate a novel approach to control the photocatalytic selectivity of TiO₂ though different dominant crystal facets. {101}, {111}, and {001} facets exposed nanoscale anatase TiO₂ were obtained by a simple hydrothermal route with different ratio of NH₄⁺ and F^?, then a calcined progress to clear surface adsorbent atoms. Results reveal that {101} exposed TiO₂ has some remain binding N with a mode of unsaturated N_3c exhibits selectively photocatalytic degradation of methylene orange (MO) in a methylene blue (MB) and methyl orange (MO) mixed solution, whereas TiO₂ with exposed {111} and {001} facets exhibits photocatalytic selectivity for MB. The {111} facets of anatase TiO₂ exhibit a better photocatalytic selective ability than {001} facets. It confirms that the photocatalytic selectivity can be affected by different dominant crystal facets. In a deeper analysis, there are many unsaturated O_2c on the surface of {001} and {111} facets, which enhances adsorbent selectivity and relevant photocatalytic activity of MB, at the same time, the unsaturated O_2c on the surface of {111} facets is much more than that on the surface of {001} facets results in a better photocatalytic selectivity of {111} facets. This research hopes that developing a new strategy for photocatalytic selectivity and providing a deeper understanding of different crystal facets of TiO₂.