Functionalized TiO₂ nanoparticles by single-step hydrothermal synthesis: the role of the silane coupling agents

• Antoine R. M. Dalod,
• Lars Henriksen,
• Tor Grande and
• Mari-Ann Einarsrud

Beilstein J. Nanotechnol. 2017, 8, 304–312, doi:10.3762/bjnano.8.33

• Because of the high surface-to-volume ratio, the intrinsic properties of titanium dioxide (TiO2) nanoparticles have led to exploitation in many fields such as in photocatalysis [1], solar cells [2], and in biomedical applications [3]. The naturally occurring phases of TiO2 are rutile (thermodynamically

• stable polymorph), brookite, and anatase [4]. Due to the differences in surface energy, anatase and brookite are more stable than rutile at nanosize, and anatase is more stable than brookite at even smaller sizes (generally below 15–30 nm) [5][6][7]. Surface modification of TiO2 nanoparticles, via core

• anatase to rutile, the thermodynamically stable polymorph of TiO2 [4]. In the case of in situ surface-functionalized TiO2 nanoparticles, the heat treatment has negligible effects on the crystallographic structure of the samples. The SEM images of heat-treated nanoparticles (Figure 8) confirmed the

Flexible photonic crystal membranes with nanoparticle high refractive index layers

• Torben Karrock,
• Moritz Paulsen and
• Martina Gerken

Beilstein J. Nanotechnol. 2017, 8, 203–209, doi:10.3762/bjnano.8.22

• (IV) oxide, mixture of rutile and anatase, 33–37 wt % in H2O from Sigma-Aldrich, St. Louis, Missouri, USA; diameter < 150 nm; ≈21 nm primary particle size of starting nanopowder). It has a high refractive index of 2.8 (rutile) to 2.5 (anatase) in the visible spectrum at 632 nm. While a continuous

Laser irradiation in water for the novel, scalable synthesis of black TiO_x photocatalyst for environmental remediation

• Massimo Zimbone,
• Giuseppe Cacciato,
• Mohamed Boutinguiza,
• Vittorio Privitera and
• Maria Grazia Grimaldi

Beilstein J. Nanotechnol. 2017, 8, 196–202, doi:10.3762/bjnano.8.21

• decrease of the photo-activity. Despite some controversial debates in the literature in the past years (mainly regarding the potential activity of the amorphous phase), it has been recently reported that both the presence of an amorphous phase or different crystalline phases (i.e., anatase and rutile, as

Nanocrystalline TiO₂/SnO₂ heterostructures for gas sensing

• Barbara Lyson-Sypien,
• Anna Kusior,
• Mieczylaw Rekas,
• Jan Zukrowski,
• Marta Gajewska,
• Katarzyna Michalow-Mauke,
• Thomas Graule,
• Marta Radecka and
• Katarzyna Zakrzewska

Beilstein J. Nanotechnol. 2017, 8, 108–122, doi:10.3762/bjnano.8.12

• experiments have been performed for H2 concentrations of 1–3000 ppm at 200–400 °C. The nanomaterials are well-crystallized, anatase TiO2, rutile TiO2 and cassiterite SnO2 polymorphic forms are present depending on the chemical composition of the powders. The crystallite sizes from XRD peak analysis are within

• diffractometer. Based on Rietveld refinement it was possible to determine the weight fractions of cassiterite SnO2, rutile TiO2 and anatase TiO2, the lattice constants and the crystallite sizes, dXRD. The 119Sn Mössbauer effect measurements were performed in transmission geometry using an MS-4 RENON spectrometer

• were found to be within a range of 54–62 m2·g−1, independent of the chemical composition. As it can be concluded from Table 3 and Figure 2, pure SnO2 exhibits the crystallographic structure of cassiterite, whereas in the case of pure TiO2 two polymorphic forms, anatase and rutile, are present with a

Ordering of Zn-centered porphyrin and phthalocyanine on TiO₂(011): STM studies

• Piotr Olszowski,
• Lukasz Zajac,
• Szymon Godlewski,
• Bartosz Such,
• Rémy Pawlak,
• Antoine Hinaut,
• Res Jöhr,
• Thilo Glatzel,
• Ernst Meyer and
• Marek Szymonski

Beilstein J. Nanotechnol. 2017, 8, 99–107, doi:10.3762/bjnano.8.11

• , Lojasiewicza 11, 30-348 Krakow, Poland, University of Basel, Department of Physics, Klingelbergstrasse 82, 4056 Basel, Switzerland 10.3762/bjnano.8.11 Abstract Zn(II)phthalocyanine molecules (ZnPc) were thermally deposited on a rutile TiO2(011) surface and on Zn(II)meso-tetraphenylporphyrin (ZnTPP) wetting

• conditions. Keywords: dye-sensitized solar cells; molecular nanostructures; phthalocyanines; porphyrins; rutile surfaces; STM imaging; Introduction There is an increasing interest in optoelectronic applications of organic molecular heterostructures which utilize inorganic substrates, such as titanium

• investigation of molecular adsorption is titanium dioxide [11][12]. The most stable and the most studied face of TiO2 is the rutile (110) surface. In the context of adsorption studies, it is important to note that the (110) face of rutile usually contains numerous oxygen vacancies, often filled with hydroxy

Nanostructured TiO₂-based gas sensors with enhanced sensitivity to reducing gases

• Wojciech Maziarz,
• Anna Kusior and
• Anita Trenczek-Zajac

Beilstein J. Nanotechnol. 2016, 7, 1718–1726, doi:10.3762/bjnano.7.164

• TiO2-based sensing materials were investigated. 2D TiO2 thin films crystallized mainly in the form of rutile, while the flower-like 3D nanostructures as anatase. The sensor based on the 2D TiO2 showed the best performance for H2 detection, while the flower-like 3D nanostructures exhibited enhanced

• XRD patterns of nanostructured TiO2 layers are demonstrated in Figure 2. It can be observed that flower-like nanostructures crystallize in the form of anatase, with rutile as a secondary phase. Due to the extremely small tin dioxide nanoparticles, no cassiterite (SnO2) diffraction peaks can be

• distinguished, which is clearly visible in Figure 2b. This problem was discussed in our previous papers [33][39]. In the case of the T30 sensor, only reflections originating from TiO2 rutile phase can be observed. Characteristic peaks at the 2θ values of 34.9°, 37.8° and 52.4° appear, which are assigned to the

Scanning probe microscopy studies on the adsorption of selected molecular dyes on titania

• Jakub S. Prauzner-Bechcicki,
• Lukasz Zajac,
• Piotr Olszowski,
• Res Jöhr,
• Antoine Hinaut,
• Thilo Glatzel,
• Bartosz Such,
• Ernst Meyer and
• Marek Szymonski

Beilstein J. Nanotechnol. 2016, 7, 1642–1653, doi:10.3762/bjnano.7.156

• the titania–sensitizer interface. In the following paper, we review the recent scanning probe microscopic research of a certain group of molecular assemblies on rutile titania surfaces as it pertains to dye-sensitized solar cell applications. We focus on experiments on adsorption of three types of

• dianhydride (PTCDA); phtalocyanines; porphyrins; rutile; scanning probe microscopy; scanning tunneling microscopy (STM); titanium dioxide (TiO2); Introduction Today it comes as no surprise that photovoltaic devices can be made of materials other than silicon. Nanocrystalline materials accompanied by organic

• ) utilizing titania as a semiconducting electrode has consistently increased [3][4][5][6][7][8][9][10][11][12]. In the following paper, we review some of the recent research of molecular assemblies on rutile titania surfaces as it pertains to dye-sensitized solar cell applications. Review Prototypical systems

Manufacturing and investigation of physical properties of polyacrylonitrile nanofibre composites with SiO₂, TiO₂ and Bi₂O₃ nanoparticles

• Tomasz Tański,
• Wiktor Matysiak and
• Barbara Hajduk

Beilstein J. Nanotechnol. 2016, 7, 1141–1155, doi:10.3762/bjnano.7.106

• results of the ellipsometry and UV–vis analyses are characterised by high accuracy and low error. Results and Discussion 1 Structural analysis of the nanoparticles The diffractogram of the TiO2 nanoparticles (Figure 2) shows diffraction lines characteristic for a tetragonal rutile (space group P42/mnm, 98

• obtained for TiO2 particles shows the (011), (020), (220) and (024) diffraction reflections corresponding to nanocrystal anatas, and (011) reflections of tetragonal rutile. In the case of Bi2O3 nanoparticles, diffraction occurred at the (021), (220), (222), (241), (243) planes of tetragonal β-Bi2O3. The

Fast diffusion of silver in TiO₂ nanotube arrays

• Wanggang Zhang,
• Yiming Liu,
• Diaoyu Zhou,
• Hui Wang,
• Wei Liang and
• Fuqian Yang

Beilstein J. Nanotechnol. 2016, 7, 1129–1140, doi:10.3762/bjnano.7.105

• structures, TiO2 nanotubes (TNT) seem to be an ideal candidate for the applications in energy storage and photovoltaics. The intrinsic poor electric conductivity and large bandgaps (approx. 3.4 eV for anatase TiO2 [18] and approx. 3.0 eV for rutile TiO2 [19][20]) have limited the applications of TiO2 of low

• correspond to the spacings of the (101), (004), (200), (105), and (215) crystal lattice planes of the anatase phase of TiO2 in accord with the values in the standard card (JCPDS NO.21-1272). No diffraction peaks for the rutile phase of TiO2 are detectable. The diffraction peaks with the 2θ values of ca. 38.1

Impact of ultrasonic dispersion on the photocatalytic activity of titania aggregates

• Hoai Nga Le,
• Frank Babick,
• Klaus Kühn,
• Minh Tan Nguyen,
• Michael Stintz and
• Gianaurelio Cuniberti

Beilstein J. Nanotechnol. 2015, 6, 2423–2430, doi:10.3762/bjnano.6.250

• conducted with commercial titanium(IV) oxide powder (Aeroxide® P25, Evonik, CAS-No. 13463-67-7), which consists of an approximately 80/20 w/w rutile/anatase mixture. MB (Merck, KGaA), a model substance in dye wastewater research [4][7], was chosen as the organic compound in the photocatalysis. The

Electrochemical coating of dental implants with anodic porous titania for enhanced osteointegration

• Amirreza Shayganpour,
• Alberto Rebaudi,
• Pierpaolo Cortella,
• Alberto Diaspro and
• Marco Salerno

Beilstein J. Nanotechnol. 2015, 6, 2183–2192, doi:10.3762/bjnano.6.224

• case, the pretreatment should not change either the crystalline phase of the formed APT or its thickness. With or without pretreatment, Tanaka et al. [23] observed a combination of anatase and rutile for APT by means of X-ray diffraction spectroscopy. On the other hand, Choi states in his extensive

• work that rutile is formed at an anodization voltage as high as 150 V, while amorphous titania is obtained at lower voltages [25]. The crystalline phase of APT is of some importance since it seems that, with respect to osteointegration, anatase is preferred over rutile [28]. Unfortunately, if rutile is

• . According to the triplet peaks appearing in Figure 5 at around 395, 519 and 639 cm−1 and upon comparison with former data available in the literature for Raman analysis of anatase titania [29][30], the APT formed in our case seems not to be rutile but rather anatase. This is in agreement with the results of

Transformations of PTCDA structures on rutile TiO₂ induced by thermal annealing and intermolecular forces

• Szymon Godlewski,
• Jakub S. Prauzner-Bechcicki,
• Thilo Glatzel,
• Ernst Meyer and
• Marek Szymoński

Beilstein J. Nanotechnol. 2015, 6, 1498–1507, doi:10.3762/bjnano.6.155

• 10.3762/bjnano.6.155 Abstract Transformations of molecular structures formed by perylene-3,4,9,10-tetracarboxylic dianhydride (PTCDA) molecules on a rutile TiO2(110) surface are studied with low-temperature scanning tunnelling microscopy. We demonstrate that metastable molecular assemblies transform into

• desired assemblies. Differences between PTCDA/TiO2(110) and PTCDA/TiO2(011) systems obtained through identical experimental procedures are discussed. Keywords: PTCDA, TiO2, rutile, self-assembly, STM; Introduction Molecular self-assembly appears to be a very powerful and versatile tool for the formation

• even more evident when combined materials, such as organic molecules adsorbed on a metal oxide surface, are examined. Thus, we have decided to perform our research on such a model system, comprising perylene-3,4,9,10-tetracarboxylic dianhydride (PTCDA) molecules adsorbed onto the (110) face of rutile

Nanostructuring of GeTiO amorphous films by pulsed laser irradiation

• Valentin S. Teodorescu,
• Cornel Ghica,
• Adrian V. Maraloiu,
• Mihai Vlaicu,
• Andrei Kuncser,
• Magdalena L. Ciurea,
• Ionel Stavarache,
• Ana M. Lepadatu,
• Nicu D. Scarisoreanu,
• Andreea Andrei,
• Valentin Ion and
• Maria Dinescu

Beilstein J. Nanotechnol. 2015, 6, 893–900, doi:10.3762/bjnano.6.92

• matrix was also evidenced in amorphous GeTiO films annealed in a conventional furnace [23]. The annealing at about 600 °C leads to the formation of Ge nanocrystals in the film matrix, which is formed by a crystallized mixture of two phases, the Ge in TiO2 anatase phase and the rutile phase (Ti in GeO2

• rutile phase). If annealing is performed at 700 °C, the (GeTi)O2 rutile phase decomposes and a layer of GeO2 nanocrystallites appears on the film surface. This clearly shows that Ge diffuses out of the film as GeO. In the case of laser annealing (irradiation), a fraction of Ge escapes from the top

• crystallized particle has the size of the initial spherical Ge amorphous particle. After the crystal growth process, the crystallized area becomes larger and the visible lattice spacing becomes 0.317 nm. The 0.317 nm lattice spacing suggests the formation of the (GeTi)O2 rutile structure [23]. The initial Ge

Tm-doped TiO₂ and Tm₂Ti₂O₇ pyrochlore nanoparticles: enhancing the photocatalytic activity of rutile with a pyrochlore phase

• Desiré M. De los Santos,
• Javier Navas,
• Teresa Aguilar,
• Antonio Sánchez-Coronilla,
• Concha Fernández-Lorenzo,
• Rodrigo Alcántara,
• Jose Carlos Piñero,
• Ginesa Blanco and
• Joaquín Martín-Calleja

Beilstein J. Nanotechnol. 2015, 6, 605–616, doi:10.3762/bjnano.6.62

• obtained with a predominant rutile phase. The photodegradation of methylene blue showed that this pyrochlore phase enhanced the photocatalytic activity of the rutile phase. Keywords: nanoparticles; photocatalysis; pyrochlore; titanium dioxide; thulium; Introduction TiO2 is one of the most efficient

• the samples annealed at 1173 K. In turn, the influence of this pyrochlore phase on the photocatalytic activity of rutile-phase TiO2 was analyzed by a study of the photodegradation of methylene blue. Experimental The synthesis method was based on the hydrolysis reaction of titanium(IV) isopropoxide

• scan conditions were from 20 to 75° with a resolution of 0.025°, taken at 40 kV and 30 mA. From the patterns obtained, the anatase and rutile mass fraction, the average crystallite size, the unit cell volume and the specific surface area were semiquantitatively estimated. The mass fraction of the

In situ scanning tunneling microscopy study of Ca-modified rutile TiO₂(110) in bulk water

• Giulia Serrano,
• Beatrice Bonanni,
• Tomasz Kosmala,
• Marco Di Giovannantonio,
• Ulrike Diebold,
• Klaus Wandelt and
• Claudio Goletti

Beilstein J. Nanotechnol. 2015, 6, 438–443, doi:10.3762/bjnano.6.44

• -modified rutile TiO2(110) surfaces immersed in high purity water. The TiO2 surface was prepared under ultrahigh vacuum (UHV) with repeated sputtering/annealing cycles. Low energy electron diffraction (LEED) analysis shows a pattern typical for the surface segregation of calcium, which is present as an

• ) rutile surface prepared under ultrahigh vacuum (UHV) conditions, which is considered to be a model system [10][11]. Ordered Ca layers have been obtained by thermally activated segregation from the bulk [1][2][3][4][5], where calcium was a common bulk impurity in the TiO2 samples [10]. A c(6 × 2

• application of Ti-based biomaterials, since the augmented wettability would enhance the interaction between the implant surface and the biological environment. In this paper we present an in situ STM investigation of a Ca overlayer thermally grown in UHV on the TiO2(110) rutile surface and then immersed in

Palladium nanoparticles anchored to anatase TiO₂ for enhanced surface plasmon resonance-stimulated, visible-light-driven photocatalytic activity

• Kah Hon Leong,
• Hong Ye Chu,
• Shaliza Ibrahim and
• Pichiah Saravanan

Beilstein J. Nanotechnol. 2015, 6, 428–437, doi:10.3762/bjnano.6.43

• ° (101) and 48.0° (200). The obtained pattern also proved the absence of the rutile and brookite phases. The presence of Pd NPs are indicated by diffraction peaks appearing at 2θ values of 40.1 and 46.7°. They were assigned to the (111) and (200) crystal plane spacings of face centered cubic (FCC) Pd

• prepared samples are purely in crystalline anatase phase with the absence of band at 445 and 612 cm−1 corresponding to the rutile phase [52]. BET surface area and XPS analysis The nitrogen adsorption–desorption isotherms and corresponding pore size distribution of the prepared samples are depicted in

A reproducible number-based sizing method for pigment-grade titanium dioxide

• Ralf Theissmann,
• Manfred Kluwig and
• Thomas Koch

Beilstein J. Nanotechnol. 2014, 5, 1815–1822, doi:10.3762/bjnano.5.192

• are separated by controlled precipitation, and colouring transition metals are removed in a bleaching process prior to calcination. In the chloride process, rutile in the form of sand or slag, for example, is treated with gaseous chlorine to form titanium tetrachloride. The titanium tetrachloride is

• crystallographic phase, anatase, or the high-temperature crystallographic phase, rutile. The chloride process leads to formation of rutile phase particles due to the high temperatures of the combustion process. Both phases have a number of advantages and disadvantages, which lead to their typical applications

• . Preferred fields of application for rutile pigments are coatings, paints, plastics and building materials, whereas anatase pigments are mainly used in cosmetics, pharmaceuticals or food. One of the most important properties of titanium dioxide is its UV absorption, which protects human skin against sunburn

Microstructural and plasmonic modifications in Ag–TiO₂ and Au–TiO₂ nanocomposites through ion beam irradiation

• Venkata Sai Kiran Chakravadhanula,
• Yogendra Kumar Mishra,
• Venkata Girish Kotnur,
• Devesh Kumar Avasthi,
• Thomas Strunskus,
• Vladimir Zaporotchenko,
• Dietmar Fink,
• Lorenz Kienle and
• Franz Faupel

Beilstein J. Nanotechnol. 2014, 5, 1419–1431, doi:10.3762/bjnano.5.154

• is amorphous as revealed by SAED pattern corresponding to bright-field TEM image of Figure 5a. After irradiation at fluences of 1 × 1012, 3 × 1012 and 1 × 1013 ions/cm2, an increase of the crystallinity of the TiO2 matrix (metrics from brookite and rutile structures) has been observed from selected

• films have been performed and it has been reported that under SHI irradiation, the crystallization evolves through the formation of TiO2 nanocrystals in rutile and anatase phases [37][45]. In a similar study an increase of the dielectric constant of the TiO2 film after 100 MeV Ag8+ ion irradiation has

• patterns with respect to pristine film (a) and different irradiation fluences are shown below. Crystallinity of the TiO2 matrix has been observed as a result of the reflections corresponding to the metrics from brookite and rutile structures from the SAED patterns from (b) to (d). UV–visible absorption and

Growth and characterization of CNT–TiO₂ heterostructures

• Yucheng Zhang,
• Ivo Utke,
• Johann Michler,
• Gabriele Ilari,
• Marta D. Rossell and
• Rolf Erni

Beilstein J. Nanotechnol. 2014, 5, 946–955, doi:10.3762/bjnano.5.108

• in the ELNES of the Ti_L2,3 and O_K edges between anatase and rutile TiO2, which could be modelled using real-space multiple-scattering calculations [57]. With all the advancements in the analytical TEM techniques and their application to characterization of carbon-based nanomaterials and metal/metal

Effects of the preparation method on the structure and the visible-light photocatalytic activity of Ag₂CrO₄

• Difa Xu,
• Shaowen Cao,
• Jinfeng Zhang,
• Bei Cheng and
• Jiaguo Yu

Beilstein J. Nanotechnol. 2014, 5, 658–666, doi:10.3762/bjnano.5.77

• within 90 min. The S-P and S-H samples exhibit a lower activity with rate constants of 0.020 and 0.012 min−1, respectively. P25 is a mixed-phase TiO2 containing 25% rutile, whit a band gap of 3.0 eV, which results in a weak visible-light absorption up to about 413 nm. Therefore, P25 still shows some

Quantum size effects in TiO₂ thin films grown by atomic layer deposition

• Massimo Tallarida,
• Chittaranjan Das and
• Dieter Schmeisser

Beilstein J. Nanotechnol. 2014, 5, 77–82, doi:10.3762/bjnano.5.7

• properties. Although the detailed interpretation of XAS measurements is very complex and not yet completely achieved, it was shown that rutile, anatase and amorphous TiO2 films, as well as quantum-confined TiO2 nanostructures exhibit distinct features at both the O-K and the TM-L2,3 edges [10][14][15]. Here

• typical of either anatase or rutile TiO2 are absent in the XAS spectra of the ALD films [17]. These crystalline phases show a split structure for feature A; a strong and sharp peak B, and distinct pre-preak features PP. Features A′ and B′ are sharper and well separated in the crystalline phases, too

• [23]. It should be noticed that Ti-L2,3 spectra with typical features of anatase and rutile TiO2 were obtained with our ALD system when TTIP was used in connection with O2-plasma instead of water [17]. O-K edge of TiO2 thin films Differently from the Ti-L2,3 spectra, the O-K XAS edge is usually

Influence of particle size and fluorination ratio of CF_x precursor compounds on the electrochemical performance of C–FeF₂ nanocomposites for reversible lithium storage

• Ben Breitung,
• M. Anji Reddy,
• Venkata Sai Kiran Chakravadhanula,
• Michael Engel,
• Christian Kübel,
• Annie K. Powell,
• Horst Hahn and
• Maximilian Fichtner

Beilstein J. Nanotechnol. 2013, 4, 705–713, doi:10.3762/bjnano.4.80

• material and carbon in each nanocomposite is presented in Table 1. The X-ray diffraction patterns of the nanocomposites are shown in Figure 2a. All nanocomposites show diffraction peaks that correspond to the FeF2 rutile structure. However, differences between the patterns can be noticed in the region

• hexagonally arranged spots in the SAED, is shown, when the SAED pattern was taken from the particle surface. The diffraction rings in the picture can be assigned to the FeF2 rutile structure. In galvanostatic measurements, the nanocomposites were cycled at different temperatures with a current density of 25

Characterization of electroforming-free titanium dioxide memristors

• John Paul Strachan,
• J. Joshua Yang,
• L. A. Montoro,
• C. A. Ospina,
• A. J. Ramirez,
• A. L. D. Kilcoyne,
• Gilberto Medeiros-Ribeiro and
• R. Stanley Williams

Beilstein J. Nanotechnol. 2013, 4, 467–473, doi:10.3762/bjnano.4.55

• , which can be considered an ordered array of oxygen vacancies in a TiO2 rutile phase, is a thermodynamically stable and metallic (at room temperature) Magnéli phase. In the unipolar switching mode [25], this conductive channel is created and destroyed during ON and OFF switching, respectively, and spans

Kelvin probe force microscopy of nanocrystalline TiO₂ photoelectrodes

• Alex Henning,
• Gino Günzburger,
• Res Jöhr,
• Yossi Rosenwaks,
• Biljana Bozic-Weber,
• Catherine E. Housecroft,
• Edwin C. Constable,
• Ernst Meyer and
• Thilo Glatzel

Beilstein J. Nanotechnol. 2013, 4, 418–428, doi:10.3762/bjnano.4.49

• investigations [39][40]. KPFM studies in UHV conditions of rutile TiO2 decorated with either nanometer-sized Pt clusters [41] or single dye molecules [42] revealed a significant impact of single particles on the surface dipole. We have investigated the surface parameters of DSC photoelectrodes on the nanoscale

• rutile TiO2 in ultrahigh vacuum [42]. Using Equation 4 with θ = 0° and measured work-function shifts of ΔΦ = −180 ± 40 mV for the Cu(I) dye and ΔΦ = 150 ± 40 mV for N719 results in 6.3 ± 1.5 D and 5.3 ± 2 D with opposite directions, respectively. The latter value is in the same range as predicted by DFT

Photocatalytic antibacterial performance of TiO₂ and Ag-doped TiO₂ against S. aureus. P. aeruginosa and E. coli

• Kiran Gupta,
• R. P. Singh,
• Ashutosh Pandey and
• Anjana Pandey

Beilstein J. Nanotechnol. 2013, 4, 345–351, doi:10.3762/bjnano.4.40

• that the annealed sample of TiO2 has both anatase and rutile phases while only an anatase phase was found in Ag-doped TiO2 nanoparticles. The decreased band-gap energy of Ag-doped TiO2 nanoparticles in comparison to TiO2 nanoparticles was investigated by UV–vis spectroscopy. The rate of recombination

• microorganisms including bacteria, fungi and viruses, because it has high photoreactivity, broad-spectrum antibiosis and chemical stability [1][2][3][4][5][6]. The photocatalytic activity of annealed TiO2 sturdily depends upon its existing phase, i.e., anatase, rutile, brokite. The anatase phase shows an

• indirect optical band gap of 3.2 eV, while the rutile phase has a direct band gap of 3.06 eV and an indirect one of 3.10 eV [7]. However, crude nanoparticles are amorphous in nature, with decreased surface area, and show a fast recombination rate of electrons and holes. Finally the antibacterial activity