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

• found to be less effective as compared to other metal oxides [8][9][10][11][12]. Thus, in order to enhance its photocatalytic activity, CuO can be used with hydrogen peroxide (H2O2) [12][13][14][15][16][17][18][19][20][21]. However, the degradation time of dyes is an important problem when using CuO as

• the degradation through the formation of radicals [6][25]. The wide band gap, high surface area of CuO nanopetals was expected to be suitable for the photocatalytic activity for the degradation of the common cationic dye methylene blue (MB), and hence initially, a study has been carried out in which

• blue (MB), in the absence and presence of H2O2, respectively. For the photocatalytic activity study, 40 mg of CuO nanopetal powder was dispersed in 40 mL of a 50 µM MB solution and allowed to stir for ≈30 min under dark conditions and was then subjected to irradiation using an incandescent lamp

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

• nanoparticles exhibit a high photocatalytic activity under simulated solar light irradiation for the degradation of Orange II dye (>95% degradation after 180 min of irradiation at an intensity of 5 mW/cm2). The heterojunction built between the ZnO nanoparticle and ZCIS QDs not only extends the light adsorption

• 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

• in all further studies. Before the complete evaluation of the photocatalytic activity, the ZnO/ZCIS material was characterized by XRD, TEM, SEM and XPS. TEM images show that ZCIS nanocrystals were dispersed at the surface of ZnO nanoparticles and that their average diameter slightly increases (≈4.5

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

• , titanium dioxide (TiO2) has been the foremost established material for degradation of organic pollutants [1][2]. In addition to its nontoxicity, abundance and relatively low cost, TiO2 also shows excellent photocatalytic activity in many degradation reactions. Unfortunately, the photocatalytic performance

• (III) oxide (Fe2O3), which is nontoxic, stable, cost effective and found abundantly in the earth. It has been reported that Fe2O3 can be used to increase the photocatalytic activity or selectivity of semiconductor photocatalysts for degradation of organic pollutants [5][6][7][8][9][10][11][12][13][14

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

• significantly. The introduction of graphene into TiO2 results in increased conductivity of the hybrid material, higher transparency and efficient charge separation of the system which causes enhanced photocatalytic activity and other novel properties [81]. Also, due to its high conductivity, graphene is highly

• . The photocatalytic activity of the hybrid has been confirmed by the conversion of CO2 to valuable hydrocarbons (CH4 and C2H6) in water vapour (Figure 2). This opens the path for new significant applications of graphene for selectively catalytic C–C coupling reaction [90]. Liu et al. have prepared TiO2

• –TiO2 make use of its photocatalytic activity, there are also some applications of shape-controlled TiO2–graphene hybrids used in pollutant abatement [100], high-performance anodes for microbial fuel cells [101], and self-cleaning applications [102]. Vanadium oxide (VO, V2O3, VO2, V2O5)–graphene hybrids

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

• and CeO2, serve as potential photocatalysts [1][2][3][4]. The properties of the metal oxide nanoparticles (surface area, band gap, porosity) determine its photocatalytic activity for the degradation of organic pollutants from water. Because of properties such as high refractive index and large band

• photocatalytic activity of the nanoparticles was investigated regarding the degradation of rhodamine B (RhB). Experimental All reactions before the sol–gel synthesis were carried out under strict anhydrous conditions by using Schlenk tubes and vacuum line techniques. Ta(OEt)5 and Ta(On-Bu)5 were purchased from

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

• maximization of the photocatalytic efficiency. An interesting route to reach this goal is the use of iron(III) added to titanium dioxide photocatalysts, which improves the photocatalytic activity under visible light reducing the recombination rates of the photo-excited carriers [38]. Also, the immobilization

• ), (004), (200), (105), (211), (204), and (215) planes, respectively, confirming the formation of nanocrystalline anatase. This characteristic is essential from the point of view of application since the crystal structure of TiO2 significantly affects the photocatalytic activity [47]. The average

• UV radiation. The combination of titania with maghemite nanoparticles induced an increase of the absorption for S3 and S4 composites above 300 nm, a convenient characteristic for photocatalytic applications. Evaluation of photocatalytic activity of the hybrid composites The photocatalytic performance

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

• a 2 MeV He+ beam with a scattering angle of 165° in normal incidence. The RUMP software was employed for the analysis of the RBS spectra. In order to evaluate the photocatalytic activity of the TiOx nanostructured film, the methylene blue (MB) discoloration test was performed [24]. The apparent

• [23]. It is worth noting the obtained black TiOx has very high absorbance in the full range of solar radiation: in particular, solar radiation spans from 0.5 eV (2.5 µm) to 5 eV (250 nm). Although it depends on other concomitant surface processes, photocatalytic activity benefits from the high

• recombination [2]. In the present work, the photocatalytic activity is measured by using the methylene blue (MB) discoloration method [27]. Samples for discolouration measurements were prepared by sandwiching the Ti substrate between a TiOx layer (irradiated surface) and a Pt nanoparticle layer, thus realizing

Optical and photocatalytic properties of TiO₂ nanoplumes

• Viviana Scuderi,
• Massimo Zimbone,
• Maria Miritello,
• Giuseppe Nicotra,
• Giuliana Impellizzeri and
• Vittorio Privitera

Beilstein J. Nanotechnol. 2017, 8, 190–195, doi:10.3762/bjnano.8.20

• ) samples exhibit the best photocatalytic activity in degrading the MB dye under UV irradiation. In order to analyze the obtained photocatalytic results, it is necessary to take into account different factors that influence the reaction. Although the macroscopic surface is the same, the active surface areas

• , and as a consequence could favor the photocatalytic activity. In order to gain more insight into the realized structure, we performed transmittance (T) and reflectance (R) measurements in the range of 200–800 nm. The optical spectra are reported in Figure 4. The transmittance spectra (Figure 4a) show

• chemical etching (in particular, Ti3+ and OH groups) are responsible for a blurring of the valence and conduction bands. Consequently, a reduction of the optical gap was reported. Ascertained of the high photocatalytic activity of the Ti (430-190) sample due to its structural and optical properties, we

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

• suggest that an appropriate pore volume with an optimized pore size distribution besides a large specific surface area of these materials, can promote a more efficient photocatalytic activity but also a higher adsorption capacity of MB molecules, which also contributes to the removal of these molecules

• 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

• photocatalytic ability of the present materials indicates that ZnO/SiO2-clay heterostructures derived from smectites showed an enhanced photocatalytic activity for the degradation of methylene blue, probably due to the most suitable textural features among these ZnO-silica clay heterostructures. The observed

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

• , Rourkela, Odisha, India 10.3762/bjnano.7.161 Abstract Photocatalytic activity of semiconductor nanostructures is gaining much importance in recent years in both energy and environmental applications. However, several parameters play a crucial role in enhancing or suppressing the photocatalytic activity

• 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

• performs considerably better than the unsupported CdS–ZnO nanostructures. In addition, both the catalysts perform significantly better under natural sunlight than under visible light (only) irradiation. In essence, this work paves way for tailoring the photocatalytic activity of semiconductor

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

• by XRD, SEM, TEM, XPS, BET, DRS and Raman spectroscopy. 5% Ce-doped ZnO rods with an average length of 130 nm and a diameter of 23 nm exhibit the highest photocatalytic activity for the degradation of the Orange II dye under solar light irradiation. The high photocatalytic activity is ascribed to the

• 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

• reported [34][35][36]. The synthesis of particles with well-defined properties is also of high importance to control the photocatalytic activity. Their optical, chemical and electronic properties are actually strongly dependent on shape, size, crystalline structure, defect concentration, and surface area

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

• migration of atoms (dopants), which determine the functionality of TiO2-based materials. Although recent success in improving the photocatalytic activity and energy storage of Li ions in TiO2-based materials has been reported [26][27][28][29], the understanding of the migration of atoms (dopants) in TiO2

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

• . Photocatalytic reduction of CO2 The photocatalytic activity of CuO–NaTaO3 samples was evaluated by photocatalytic reduction of CO2 in isopropanol under UV light irradiation for 6 h. Methanol and acetone were generated as the reduction product of CO2 and the oxidation product of isopropanol, respectively. 2M

• photocatalytic activity. The high crystalline quality correlates to a low number of defects. The defects usually function as recombination centers where photogenerated electrons and holes recombine fast, resulting in poor photocatalytic activity [41]. Among these catalysts, 2M-NaTaO3 had the best morphology

• efficiently split water. In the 21st century, the study of Ta catalysts for the reduction of CO2 began. Kentaro Teramura et al. [15] prepared ATaO3 (A = Li, Na, K) compounds using a solid state reaction (SSR) method to reduce CO2 in the presence of H2. The only product was CO and the order of photocatalytic

Hierarchical coassembly of DNA–triptycene hybrid molecular building blocks and zinc protoporphyrin IX

• Rina Kumari,
• Sumit Singh,
• Mohan Monisha,
• Sourav Bhowmick,
• Anindya Roy,
• Neeladri Das and
• Prolay Das

Beilstein J. Nanotechnol. 2016, 7, 697–707, doi:10.3762/bjnano.7.62

• . We also report excellent photocatalytic activity of these composite nanostructures wherein the oxidation of dihydrorhodamine 123 (DHR 123) into rhodamine 123 (R 123) under UV irradiation has been studied in aqueous environment. Furthermore, these composites exhibit higher catalytic activity with

• angle of 165°. The data acquisition time for each measurement was 1 h. All buffer solutions were filtered through syringe filters prior to use to remove dust particles. Photocatalytic activity of composite nanostructure The photocatalytic efficiency of composite DNA nanostructure was evaluated by

• ) after conjugation and assembly with DNA complementary strands. Interestingly, coassembly of DNA–TPA building block units and Zn PpIX generates DNA nanofibers showing enhanced photocatalytic activity. These features have been identified and confirmed by native PAGE, AFM, CD and spectroscopic analyses. It

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

• path of the molecules to be treated. This paper investigates the effect of aggregate size on the photocatalytic activity of pyrogenic titania (Aeroxide® P25, Evonik), which is widely used in fundamental photocatalysis research. Well-defined and reproducible aggregate sizes were achieved by ultrasonic

• dispersion. The photocatalytic activity was examined by the color removal of methylene blue (MB) with a laboratory-scale setup based on a plug flow reactor (PFR) and planar UV illumination. The process parameters such as flow regime, optical path length and UV intensity are well-defined and can be varied

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

• required in order to obtain the photoactive anatase phase. However, Na+ ions have a detrimental effect on the photocatalytic efficiency of TiO2 [3][4][7]. The poisoning effect of the Na+ ions on the photocatalytic activity occurs in different ways and depends on their concentration, for example: (a) Na

• at grazing incidence (0.05°). Silicon powder was dispersed on the coating surface in order to calibrate the diffractograms. The photocatalytic activity of the films was evaluated by observing the photobleaching of Orange II (OII) dye with an initial concentration [OII] = 10 mg·L−1 over the course of

• the initial absorbance. The bleaching of the dye was thus quantitatively evaluated by recording the “real time” evolution of the maximum absorbance value of the OII, at 485.5 nm, at neutral pH 7.2, using a quartz circulating cell placed in a UV–vis spectrometer. The photocatalytic activity of the

Temperature-dependent breakdown of hydrogen peroxide-treated ZnO and TiO₂ nanoparticle agglomerates

• Sinan Sabuncu and
• Mustafa Çulha

Beilstein J. Nanotechnol. 2015, 6, 1897–1903, doi:10.3762/bjnano.6.193

• photocatalytic activity of the NPs [23]. The objective of this study is to disintegrate MONP agglomerates using heat and H2O2 treatment without the use of any additional chemicals. ZnO and TiO2 NPs were chosen due to their widespread use in several industrial applications. The H2O2 treatment not only eliminates

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

• 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

• synthesized. The photocatalytic activity of pure and V-doped SrTiO3 porous nanofibers were evaluated by the decomposition of methyl orange (MO) in aqueous solution under UV–vis light irradiation. In Figure 3a, the characteristic absorption peak of MO at approx. 464 nm is given which shows a progressive

• photocatalytic activity of V-doped SrTiO3 nanofibers compared to pure SrTiO3 nanofibers can be attributed to the V5+ ion doping. Stability and reusability are also very important for photocatalysts. As shown in the upper left inset in Figure 3b, the catalytic efficiency of V-doped SrTiO3 nanofibers is barely

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

• absorption spectroscopy and Raman spectroscopy. XRD studies showed the presence of ZnO and CuO nanostructures in the nanocomposites. FESEM images revealed the presence of nanosheets and nanorods in the nanocomposites. The photocatalytic activity of ZnO–CuO nanocomposites was evaluated on the basis of

• enhanced photocatalytic activity of ZnO–CuO nanocomposites is proposed. We attribute the observed enhanced photocatalytic activity of ZnO–CuO nanocomposites to the combined effects of improved sun light utilization and suppression of the recombination of photogenerated charge carriers in ZnO–CuO

• carbothermal reduction-based vapor deposition method. We have demonstrated that swift heavy ion irradiation can be employed to significantly enhance the sun light driven photocatalytic activity of ZnO–CuO nanocomposites toward the degradation of methylene blue (MB) and methyl orange (MO) dyes in water. Results

Transformation of hydrogen titanate nanoribbons to TiO₂ nanoribbons and the influence of the transformation strategies on the photocatalytic performance

• Melita Rutar,
• Nejc Rozman,
• Matej Pregelj,
• Carla Bittencourt,
• Romana Cerc Korošec,
• Andrijana Sever Škapin,
• Aleš Mrzel,
• Srečo D. Škapin and
• Polona Umek

Beilstein J. Nanotechnol. 2015, 6, 831–844, doi:10.3762/bjnano.6.86

• TiO2 [22] in which the nitrogen atoms occupy substitutional and interstitial sites in the TiO2 and thus affect the photocatalytic activity of titania for reactions performed under visible-light irradiation [3][5][23][24]. On the other hand, transformation under wet-chemical or hydrothermal conditions

• PP of CH-W and MW-W. The specific surface area and the crystallinity are two of the key factors that strongly affect the photocatalytic activity of TiO2. Therefore, with the aim to improve the crystallinity of the TiO2 NRs the samples with the highest specific surface area (CH-W and MW-W) were

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

• 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

• studies in the literature in which pyrochlore-type compounds with high photocatalytic activity are used as a photocatalysts, such as Bi2Ti2O7 [9][10], Pb2Nb2O7 [11]; other pyrochlore compounds that have been evaluated are rare earths, such as Gd2BiSbO7 [12] or Ln2Ti2O7 (Ln = Nd, Gd, Er) [13]. In this

Novel ZnO:Ag nanocomposites induce significant oxidative stress in human fibroblast malignant melanoma (Ht144) cells

• Syeda Arooj,
• Samina Nazir,
• Akhtar Nadhman,
• Nafees Ahmad,
• Bakhtiar Muhammad,
• Ishaq Ahmad,
• Kehkashan Mazhar and
• Rashda Abbasi

Beilstein J. Nanotechnol. 2015, 6, 570–582, doi:10.3762/bjnano.6.59

• exhibit an improved photocatalytic activity [26][27] and photostability [28] compared to the ZnO NPs. Nanoscale Ag2+ itself exhibits antimicrobial and anticancer activity [29], therefore it might be a very interesting and useful addition to the ZnO NPs as it not only enhances the photocatalytic activity

• , reduction in size of the NPs and increase in the photocatalytic activity [26][34]. It is, however, not well-understood how these NPs exactly work in the exposed cells. ZnO NPs were reported to cause toxicity by generating ROS [35], causing DNA damage, oxidative stress [36], an increase in caspase-3 activity

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

• with controlled Pd NPs size ranging between 17 and 29 nm onto the surface of TiO2. Thus, it gives the characteristic for Pd NPs to absorb light in the visible region obtained through localized surface plasmon resonance (LSPRs). Apparently, the photocatalytic activity of the prepared photocatalysts was

• Honda in 1972 [1]. To date, TiO2 is still the most favorable choice owing to its versatility and robust advantages that include photostability, non-toxicity, low cost, chemical and biological inertness, high photocatalytic activity and favorable optoelectronic properties [2][3][4][5]. TiO2 also

• -dimensional anatase TiO2/Ag, which exhibited an excellent photocatalytic activity with almost 100% degradation of 2,4-dichlorophenol within 2 h [26]. Likewise, Hou et al. reported a 9-fold improvement in the photocatalytic decomposition rate of methyl orange driven by a photocatalyst consisting of robust

Rapid degradation of zinc oxide nanoparticles by phosphate ions

• Rudolf Herrmann,
• F. Javier García-García and
• Armin Reller

Beilstein J. Nanotechnol. 2014, 5, 2007–2015, doi:10.3762/bjnano.5.209

• recently [23]. Special attention to the effects of phosphate around neutral pH has been payed only very recently [24]. The photocatalytic activity of ZnO nanoparticles can be significantly reduced by coating with SiO2 [25]. This is important when ZnO-NP are applied as UV blockers. We therefore also

• phosphate buffers. Photocatalytic activity of ZnO-NP, e.g., in oxidation reactions, is an unwanted feature when they are to be applied as UV blockers. Among the suggested coatings, which should block this activity, silica is mostly used in commercial preparations [25]. In principle, coatings should also

• zinc phosphate, which does not lead to precipitation and equilibrium shifts. In the light of these results it seems essential to ensure a tight coating by a chemically resistant material before applying ZnO-NP for, e.g., medical or cosmetic purposes. Silica coating can suppress photocatalytic activity

Enhanced photocatalytic hydrogen evolution by combining water soluble graphene with cobalt salts

• Jing Wang,
• Ke Feng,
• Hui-Hui Zhang,
• Bin Chen,
• Zhi-Jun Li,
• Qing-Yuan Meng,
• Li-Ping Zhang,
• Chen-Ho Tung and
• Li-Zhu Wu

Beilstein J. Nanotechnol. 2014, 5, 1167–1174, doi:10.3762/bjnano.5.128

• carbon nanotubes, a small fraction of the electrons may get stored in graphene sheets, thus making graphene an electron reservoir to continuously provide electrons to the catalytic center [58][59][60]. The positive synergetic effect consequently enhances the photocatalytic activity for hydrogen evolution