Evaluating the toxicity of TiO₂-based nanoparticles to Chinese hamster ovary cells and Escherichia coli: a complementary experimental and computational approach

• Alicja Mikolajczyk,
• Natalia Sizochenko,
• Ewa Mulkiewicz,
• Anna Malankowska,
• Michal Nischk,
• Przemyslaw Jurczak,
• Seishiro Hirano,
• Grzegorz Nowaczyk,
• Adriana Zaleska-Medynska,
• Jerzy Leszczynski,
• Agnieszka Gajewicz and
• Tomasz Puzyn

Beilstein J. Nanotechnol. 2017, 8, 2171–2180, doi:10.3762/bjnano.8.216

• (Brunauer–Emmett–Teller surface, BET) of nanoparticles were discussed. Keywords: Au/Pd–TiO2 photocatalyst; bimetallic nanoparticles; nanotoxicity; nano-QSAR; second-generation nanoparticles; Introduction Unmodified titania (TiO2) nanoparticles (so-called first-generation NPs) represent a material that

• alters the rate of chemical reactions, when exposed to light (photocatalyst) [1]. TiO2-based NPs have already found wide applications as efficient photocatalysts for sterilization, sanitation, air and water purification systems, hydrogen production by water splitting, and dye-sensitized solar cells [1

Two-dimensional carbon-based nanocomposites for photocatalytic energy generation and environmental remediation applications

• Suneel Kumar,
• Ashish Kumar,
• Ashish Bahuguna,
• Vipul Sharma and
• Venkata Krishnan

Beilstein J. Nanotechnol. 2017, 8, 1571–1600, doi:10.3762/bjnano.8.159

• nanocomposites. Then, the development of various graphene-based nanocomposites for the above-mentioned applications is presented, wherein graphene plays different roles, including electron acceptor/transporter, cocatalyst, photocatalyst and photosensitizer. Subsequently, the development of different graphitic

• environmental remediation and energy generation applications [29][30][31][32]. Semiconductor nanocomposite-based photocatalytic reactions are generally initiated by absorbing light energy equal to or more than the band gap of semiconductor photocatalyst [4]. This leads to the excitation of electrons from the

• valence band (VB) of the semiconductor to their empty conduction band (CB), resulting in the electron–hole pair generation [4]. This photoexcitation process leaves a hole in the VB of the photocatalyst, which can oxidize water of OH− at its surface to produce hydroxyl radical (OH*), which is a powerful

Enhanced catalytic activity without the use of an external light source using microwave-synthesized CuO nanopetals

• Govinda Lakhotiya,
• Sonal Bajaj,
• Arpan Kumar Nayak,
• Debabrata Pradhan,
• Pradip Tekade and
• Abhimanyu Rana

Beilstein J. Nanotechnol. 2017, 8, 1167–1173, doi:10.3762/bjnano.8.118

• with the development of cost effective and ecologically friendly methods [2]. Metal oxides have attracted significant attention as a photocatalyst for the degradation of these pollutants [3][4][5][6]. Copper oxide (CuO) is one of the most efficient materials for the oxidation of the air pollutant

• the photocatalyst. Here, we have adopted the simple microwave-assisted route for the wet chemical surfactantless synthesis of copper oxide (CuO) nanostructures (nanoflowers and nanopetals) having a large specific surface area. The catalytic reaction of CuO nanopetals and H2O2 was studied under the

• blue degradation in the absence of CuO nanopetals (catalyst) under dark conditions. (d) UV–vis absorption spectrum of methylene blue degradation using CuO nanopetals as a photocatalyst for different durations. (a) UV–vis absorption spectra for MB degradation for different duration for 10 mg nanopetals

ZnO nanoparticles sensitized by CuInZn_xS_2+x quantum dots as highly efficient solar light driven photocatalysts

• Florian Donat,
• Serge Corbel,
• Halima Alem,
• Steve Pontvianne,
• Lavinia Balan,
• Ghouti Medjahdi and
• Raphaël Schneider

Beilstein J. Nanotechnol. 2017, 8, 1080–1093, doi:10.3762/bjnano.8.110

• range by the photocatalyst but also acts to decrease electron/hole recombination. Interestingly, the ZnO/ZCIS composite was found to produce increased amounts of H2O2 and singlet oxygen 1O2 compared to ZnO, suggesting that these reactive oxygen species play a key role in the photodegradation mechanism

• generating UV-A and UV-B radiation. In this paper, we report first the successful preparation of a ZnO/ZCIS heterostructured photocatalyst using commercial ZnO nanoparticles and only 2.5 wt % of ZCIS QDs. The high photocatalytic activity of this material for the degradation of Orange II dye under simulated

• solar light irradiation was demonstrated. The ZnO/ZCIS photocatalyst was found to possess high stability and could be reused at least ten times without significant loss of activity. Additionally, it was found to be only weakly sensitive to interfering substances such as salts present in the aqueous

High photocatalytic activity of Fe₂O₃/TiO₂ nanocomposites prepared by photodeposition for degradation of 2,4-dichlorophenoxyacetic acid

• Shu Chin Lee,
• Hendrik O. Lintang and
• Leny Yuliati

Beilstein J. Nanotechnol. 2017, 8, 915–926, doi:10.3762/bjnano.8.93

• photodeposition showed higher photocatalytic activity than the unmodified TiO2. Three times higher photocatalytic activity was obtained on the best photocatalyst, Fe2O3(0.5)/TiO2. The improved activity of TiO2 after photodeposition of Fe2O3 was contributed to the formation of a heterojunction between the Fe2O3

• stability and reusability, suggesting its potential for water purification applications. Keywords: 2,4-dichlorophenoxyacetic acid; Fe2O3/TiO2; herbicide degradation; heterojunction; holes and superoxide radicals; photocatalyst; photodeposition; water purification; Introduction Photocatalytic reactions

• have been widely suggested for environmental remediation under mild conditions. In the presence of only a photocatalyst and a light source of appropriate energy, the process can mineralize organic pollutants to harmless products such as carbon dioxide and water. Among the semiconductor photocatalysts

Synthesis of graphene–transition metal oxide hybrid nanoparticles and their application in various fields

• Arpita Jana,
• Elke Scheer and
• Sebastian Polarz

Beilstein J. Nanotechnol. 2017, 8, 688–714, doi:10.3762/bjnano.8.74

• and electrical properties. It has been used as a heterogeneous photocatalyst and it has outstanding advantages because of its low cost, scalability, nontoxicity, strong photo-oxidising power and stability in oxidative and acidic environments [78]. Extensive research on TiO2 nanomaterials has shown

Investigation of the photocatalytic efficiency of tantalum alkoxy carboxylate-derived Ta₂O₅ nanoparticles in rhodamine B removal

• Subia Ambreen,
• Mohammad Danish,
• Narendra D. Pandey and
• Ashutosh Pandey

Beilstein J. Nanotechnol. 2017, 8, 604–613, doi:10.3762/bjnano.8.65

• with the Scherrer equation, are in the range of 15–28 nm. The samples attained good crystallinity after calcination at 750 °C. SEM micrographs show that the synthesized samples are almost spherical and agglomerate to some extent. The photodegradation of rhodamine B by the semiconductor photocatalyst

Photocatalysis applications of some hybrid polymeric composites incorporating TiO₂ nanoparticles and their combinations with SiO₂/Fe₂O₃

• Andreea Laura Chibac,
• Tinca Buruiana,
• Violeta Melinte and
• Emil C. Buruiana

Beilstein J. Nanotechnol. 2017, 8, 272–286, doi:10.3762/bjnano.8.30

• separation and recycling of photocatalyst particles from aqueous suspension can appear. In order to eliminate or at least diminish the limitations mentioned, many studies were directed on obtaining TiO2-based materials that are active under solar/visible light. It has been demonstrated that the increase of

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

• irradiation. We employed a commercial high repetition rate green laser in order to synthesize a black TiOx layer and we demonstrate the scalability of the present methodology. The photocatalyst is composed of a nanostructured titanate film (TiOx) synthetized on a titanium foil, directly back-contacted to a

• irradiation in the presence of black TiOx material (black) and without the photocatalyst (green) are reported. The MB concentration follows a pseudo first-order kinetic law in the first 10 hours of irradiation. The discoloration rate constant k is measured by fitting the curve in Figure 6 with the following

• the TiOx/Ti film in the IR, visible and UV spectral range. UV discoloration of methylene blue (MB) dye in the presence of TiOx/Ti/Pt foil. The discoloration of a MB solution without photocatalyst is also reported for comparison purposes. Acknowledgements This research has been supported by the FP7

Organoclay hybrid materials as precursors of porous ZnO/silica-clay heterostructures for photocatalytic applications

• Marwa Akkari,
• Pilar Aranda,
• Abdessalem Ben Haj Amara and
• Eduardo Ruiz-Hitzky

Beilstein J. Nanotechnol. 2016, 7, 1971–1982, doi:10.3762/bjnano.7.188

• microparticulated layered silicates of the smectite family, giving rise to materials exhibiting interesting properties [8][9]. The immobilization of those NP on clay surfaces represents an advantage for the easier recovering of the photocatalyst from the reaction medium compared to ZnO NP alone. In recent years

• different applications as a photocatalyst. Hence, their activity has been tested using methylene blue (MB) model dye molecule. Figure 11 shows the concentration of methylene blue solutions (C/C0) as a function of the UV irradiation time in presence of SiO2/ZnO montmorillonite and ZnO/SiO2-sepiolite

• photocatalyst for the degradation of drug pollutants in water, ibuprofen was selected as a model pharmaceutical. Ibuprofen shows a low adsorption affinity towards silica/silicate substrates and the observed degradation could be directly related to the photocatalytic activity of the tested materials. Figure 12

Role of RGO support and irradiation source on the photocatalytic activity of CdS–ZnO semiconductor nanostructures

• Suneel Kumar,
• Rahul Sharma,
• Vipul Sharma,
• Gurunarayanan Harith,
• Vaidyanathan Sivakumar and
• Venkata Krishnan

Beilstein J. Nanotechnol. 2016, 7, 1684–1697, doi:10.3762/bjnano.7.161

• the photocatalysts. In this work, we have investigated the role of reduced graphene oxide (RGO) support and the irradiation source on mixed metal chalcogenide semiconductor (CdS–ZnO) nanostructures. The photocatalyst material was synthesized using a facile hydrothermal method and thoroughly

• characterized using different spectroscopic and microscopic techniques. The photocatalytic activity was evaluated by studying the degradation of a model dye (methyl orange, MO) under visible light (only) irradiation and under natural sunlight. The results reveal that the RGO-supported CdS–ZnO photocatalyst

• with other semiconductor materials to form nanocomposites, they turn out be an efficient photocatalyst [25]. Recently, there have been few reports available in literature on CdS–ZnO coupled photocatalytic systems with enhanced activity [26]. On illumination of light, charge transfer takes place from

High performance Ce-doped ZnO nanorods for sunlight-driven photocatalysis

• Bilel Chouchene,
• Tahar Ben Chaabane,
• Lavinia Balan,
• Emilien Girot,
• Kevin Mozet,
• Ghouti Medjahdi and
• Raphaël Schneider

Beilstein J. Nanotechnol. 2016, 7, 1338–1349, doi:10.3762/bjnano.7.125

• no marked detrimental effect on the photocatalytic activity was observed. Finally, recyclability experiments demonstrate that ZnO:Ce rods are a stable solar-light photocatalyst. Keywords: Ce doping; photocatalysis; solvothermal synthesis; ZnO rods; Introduction Due to the increasing pollution of

• adequate wavelength by the semiconductor, electrons (e−) are promoted from the valence band (VB) to the conduction band (CB) and holes (h+) generated in the VB to form electron–hole pairs. Most of these e−/h+ pairs recombine and only a small percentage migrate to the surface of the photocatalyst where they

• semiconductor photocatalyst owing to its availability, weak toxicity, stability and relatively good resistance to photocorrosion [2][3][4][5][6][7]. However, to efficiently use ZnO in practice as an air and water decontamination agent, two drawbacks should be overcome. First, ZnO is a wide bandgap material (Eg

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

• composite nanofibres obtained by Ji Sun Im, Min Il Kim and Young-Seak Lee [36]. This leads to a significant increase in the specific surface area of the composite mats related to receiving more efficient photocatalyst materials. It is anticipated that the Bi2O3-reinforced composite PAN nanofibres produced

• by the authors hereof, due to their photocatalyst properties [37], can provide a more effective alternative to the previously produced PAN/TiO2 nanofibres. In addition, in the a stage of the study, it is planned to examine the effects even larger distances between the electrodes while maintaining the

Selective photocatalytic reduction of CO₂ to methanol in CuO-loaded NaTaO₃ nanocubes in isopropanol

• Tianyu Xiang,
• Feng Xin,
• Jingshuai Chen,
• Yuwen Wang,
• Xiaohong Yin and
• Xiao Shao

Beilstein J. Nanotechnol. 2016, 7, 776–783, doi:10.3762/bjnano.7.69

• visible light absorbance correlates with the formation rate and increase in electrons and holes on the photocatalyst surface [35]. Energy-dispersive X-ray spectroscopy (EDS) and X-ray photoelectron spectroscopy (XPS) were carried out to confirm that CuO was loaded onto the surface of NaTaO3 nanocubes

• , 2wt-NaTaO3 and 5wt-NaTaO3. Methanol and acetone yields for 2M-NaTaO3 loaded with different amounts of CuO after 6 h of irradiation. Schematic diagram for photocatalytic reduction of CO2 to methanol in CuO–NaTaO3 photocatalyst under UV light irradiation. Acknowledgements We gratefully thank the

Synthesis and applications of carbon nanomaterials for energy generation and storage

• Marco Notarianni,
• Jinzhang Liu,
• Kristy Vernon and
• Nunzio Motta

Beilstein J. Nanotechnol. 2016, 7, 149–196, doi:10.3762/bjnano.7.17

• 15 and a conductivity of 300 S/cm with HI acid. Derivative approaches of the chemical method have also been employed to reduce GO: photocatalyst reduction where the GO mixed with TiO2 particles is exposed to ultraviolet (UV) irradiation [131]; electrochemical reduction with an inert electrode placed

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

• effectiveness of photocatalytic materials increases with the specific surface area, thus nanoscale photocatalyst particles are preferred. However, such nanomaterials are frequently found in an aggregated state, which may reduce the photocatalytic activity due to internal obscuration and the extended diffusion

• promising photocatalyst because of its commercial availability, chemical and biological inertness, and because it has no known adverse health effects on humans [5][6]. Due to its large active surface area, the suspended TiO2 powder is favored [6]. Most slurry photocatalysts have been implemented in

• experimental setup, which defines the process parameters. In addition, ultrasonic dispersion was used to disintegrate the P25 nano-photocatalyst as well as vary the size. The photocatalytic activity was examined by the discoloration of MB under UV irradiation. Experimental Materials All experiments were

Effect of SiN_x diffusion barrier thickness on the structural properties and photocatalytic activity of TiO₂ films obtained by sol–gel dip coating and reactive magnetron sputtering

• Mohamed Nawfal Ghazzal,
• Eric Aubry,
• Nouari Chaoui and
• Didier Robert

Beilstein J. Nanotechnol. 2015, 6, 2039–2045, doi:10.3762/bjnano.6.207

• presence of an uncoated SLG under UV–vis illumination or in the dark in the presence of the TiO2 photocatalyst. Thus, the OII was not photobleached by photolysis nor was it adsorbed at the surface of the photocatalyst, which suggests a neglected effect of the specific surface area of the film on the

• the adsorption/bleaching of the azo molecule [18]. This means that even the dye molecule OII could absorb visible light to produce the excited singlet and/or triplet state of the OII molecule [19], the OII may be able to sensitize the TiO2 photocatalyst. However, the degradation of the OII dye via the

• increasing the SiNx diffusion barrier thickness affects the interfacial electron transfer rate [20]. The photo-generated electron–hole pair produced in the bulk of the photocatalyst during the illumination diffuses faster to reach the surface, since the distance traveled is reduced by the smaller crystallite

High photocatalytic activity of V-doped SrTiO₃ porous nanofibers produced from a combined electrospinning and thermal diffusion process

• Panpan Jing,
• Wei Lan,
• Qing Su and
• Erqing Xie

Beilstein J. Nanotechnol. 2015, 6, 1281–1286, doi:10.3762/bjnano.6.132

• /bjnano.6.132 Abstract In this letter, we report a novel V-doped SrTiO3 photocatalyst synthesized via electrospinning followed by a thermal diffusion process at low temperature. The morphological and crystalline structural investigations reveal not only that the V-doped SrTiO3 photocatalyst possesses a

• photocatalytic activity with excellent endurance. Results and Discussion The morphology and microstructure are very important for the development of an excellent photocatalyst. In Figure 1a, the pure SrTiO3 nanofibers appear to be tens of micrometers in length, with a porous surface and uniform diameter

• distribution. The pore size and diameter distributions were measured to be about 10–32 nm and 90–240 nm, respectively. Such a long fibrous and porous structure is beneficial to electron transfer, dye molecular absorption and the light utilization efficiency for a photocatalyst. In Figure 1b, the morphological

Effects of swift heavy ion irradiation on structural, optical and photocatalytic properties of ZnO–CuO nanocomposites prepared by carbothermal evaporation method

• Sini Kuriakose,
• D. K. Avasthi and
• Satyabrata Mohapatra

Beilstein J. Nanotechnol. 2015, 6, 928–937, doi:10.3762/bjnano.6.96

• of CuO. This helps to inhibit the recombination of photogenerated electrons and holes and improves the charge separation efficiency. The oxygen molecules adsorbed on the photocatalyst form superoxide anion radicals (•O2−) due to their interaction with electrons in the conduction band of ZnO. Surface

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

• semiconductors used as a photocatalyst for the degradation of organic compounds. This is due to its high chemical and biological stability, low cost, excellent electronic and optical properties, and the strong oxidation capacity of its photogenerated holes [1][2]. Photocatalytic activity depends on several

• catalytic properties, such as band gap energy, specific surface area, the extent of crystallinity, the structure of the material, etc. [3]. In general, a good photocatalyst should efficiently absorb photons with an energy equal to or higher than its band gap, thus generating an electron–hole pair. These

• photodegradation of methylene blue (MB) was performed using a set of five actinic lamps emitting at around 360 nm. The initial concentration of the aqueous solution of MB (purity 82%, Panreac) was 1.56 · 10−5 M, and the concentration of the photocatalyst was 0.3 g·L−1. The photocatalyst/MB mixture was kept 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

• Lumpur, Malaysia 10.3762/bjnano.6.43 Abstract Freely assembled palladium nanoparticles (Pd NPs) on titania (TiO2) nano photocatalysts were successfully synthesized through a photodeposition method using natural sunlight. This synthesized heterogeneous photocatalyst (Pd/TiO2) was characterized through

• ; nano photocatalysts; noble metal; photodeposition; sunlight; Introduction Heterogeneous photocatalysts that employ TiO2 as metal oxide photocatalyst have raised the interest of many researchers since the discovery of the photocatalytic splitting of water under UV light irradiation by Fujishima and

• collective oscillation of conduction electrons that are induced by the incident electromagnetic radiation [9]. Moreover, the formation of Schottky barriers caused by the contact of noble metal NPs with the semiconductor photocatalyst further enhance the separation of electrons and holes, which in turn reduce

Inorganic Janus particles for biomedical applications

• Isabel Schick,
• Steffen Lorenz,
• Dominik Gehrig,
• Stefan Tenzer,
• Wiebke Storck,
• Karl Fischer,
• Dennis Strand,
• Frédéric Laquai and
• Wolfgang Tremel

Beilstein J. Nanotechnol. 2014, 5, 2346–2362, doi:10.3762/bjnano.5.244

• und the excitation of charge carriers within the photocatalyst [48]. Upon conjugation of semiconductor nanoparticles, such as TiO2 to metal nanoparticles, charge equilibration takes place when the composite material is photoexited (Figure 6c). As a direct consequence, the Fermi level of semiconductor

Synthesis of hydrophobic photoluminescent carbon nanodots by using L-tyrosine and citric acid through a thermal oxidation route

• Venkatesh Gude

Beilstein J. Nanotechnol. 2014, 5, 1513–1522, doi:10.3762/bjnano.5.164

• quantum yield of the mixture of CNDs [37]. Another interesting optical property of these tyrosine-passivated CNDs is upconversion photoluminescence (UCPL) when irradiated with wavelengths above 500 nm, which is very important for applications as photocatalyst and for light harvesting applications [2][5

Characterization and photocatalytic study of tantalum oxide nanoparticles prepared by the hydrolysis of tantalum oxo-ethoxide Ta₈(μ₃-O)₂(μ-O)₈(μ-OEt)₆(OEt)₁₄

• Subia Ambreen,
• N D Pandey,
• Peter Mayer and
• Ashutosh Pandey

Beilstein J. Nanotechnol. 2014, 5, 1082–1090, doi:10.3762/bjnano.5.121

• thermal stability of the as-prepared (dried) photocatalyst with α-Al2O3 as the reference. Figure 6 shows the TG/DTA/DSC curves obtained from the dried gel of Ta2O5. The TGA graph shows a weight loss up to a temperature of 200 °C that is essentially attributed to dehydration. The decomposition of organic

• degradation of rhodamine B Figure 12 shows the degradation of dye for different of the catalyst loadings. It is clear that the optimum (89%) degradation of the dye was achieved (after 150 minutes) when 0.8 mg/mL of the photocatalyst was used in the experiment. However, when the used amounts of photocatalyst

• were 0.2 mg/mL, 0.5 mg/mL and 1.1 mg/mL, the degradation of dye occurred up to 55%, 68% and 74%, respectively. The amount of the photocatalyst was changed in each experiment while keeping the other factors invariable to study the optimum degradation of dye with respect to the amount of Ta2O5. By

DFT study of binding and electron transfer from colorless aromatic pollutants to a TiO₂ nanocluster: Application to photocatalytic degradation under visible light irradiation

• Corneliu I. Oprea,
• Petre Panait and
• Mihai A. Gîrţu

Beilstein J. Nanotechnol. 2014, 5, 1016–1030, doi:10.3762/bjnano.5.115

• ; density functional theory; photocatalytic degradation; titanium dioxide; visible light irradiation; Introduction Titania, TiO2, has been widely used as photocatalyst for environmental applications [1][2][3][4][5][6], particularly for waste water purification. Due to its large band gap TiO2 absorbs only

• UV radiation, a fact that limits the efficiency and keeps the costs of the photocatalytic degradation of environmental pollutants high. To be used under visible light irradiation, in the range of wavelengths where the solar spectrum has its maximum, the electronic band structure of the photocatalyst

• has to be modified in various ways [6]. Alternative approaches to the modification of the TiO2 photocatalyst are the self-sensitized degradation of dyes which absorb visible light [7][8] and the photocatalytic degradation of colorless organic compounds by formation of a charge-transfer-complex, CTC [9