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

• gel was left at room temperature for 24 h for aging. It was then dried at 90 °C for 12 h to remove the solvent and other volatile residues to provide a white to off-white powder, which after calcination afforded Ta2O5 nanoparticles. Photocatalytic degradation of rhodamine B over Ta2O5 nanoparticles

• of tantalum alkoxides were subjected to hydrolysis and condensation reactions. The obtained particles were dried earlier to calcination to remove adsorbed water, impurities and volatilities. Ta2O5 nanoparticles obtained from Ta(OR)5 and Ta(OR)4(OOCR′) (R = CH2CH3/CH(CH3)2/CH2CH2CH2CH3, R′ = CH2Cl

• intensify significantly and become much sharper with the rise in calcination temperature indicating that the crystallinity of Ta2O5 nanoparticles increases. As the calcination temperature is elevated to 750 °C, several intense and sharp diffraction peaks appeared. XRD patterns of Ta2O5 samples prepared from

Diffusion and surface alloying of gradient nanostructured metals

• Zhenbo Wang and
• Ke Lu

Beilstein J. Nanotechnol. 2017, 8, 547–560, doi:10.3762/bjnano.8.59

• amorphous titania. Furthermore, the formed titania showed an increased crystallinity and retained the nanoporous structure even after calcination at 600 °C [94]. These works indicated the possibility to improve the bioactivity of titanium bone implants and to accelerate osseointegration by introducing a

Nanocrystalline ZrO₂ and Pt-doped ZrO₂ catalysts for low-temperature CO oxidation

• Amit Singhania and
• Shipra Mital Gupta

Beilstein J. Nanotechnol. 2017, 8, 264–271, doi:10.3762/bjnano.8.29

• calcination temperatures of ZrO2 and the amount of fuel on ZrO2 nanoparticles and their catalytic activity for CO oxidation. In later stages, it is also planned to work with different Pt percentages on ZrO2 to further lower down the temperatures required for CO oxidation. Experimental Materials synthesis All

From iron coordination compounds to metal oxide nanoparticles

• Mihail Iacob,
• Carmen Racles,
• Codrin Tugui,
• George Stiubianu,
• Adrian Bele,
• Liviu Sacarescu,
• Daniel Timpu and
• Maria Cazacu

Beilstein J. Nanotechnol. 2016, 7, 2074–2087, doi:10.3762/bjnano.7.198

• employing either a classical thermal pathway (i.e., thermal decomposition in solution, solvothermal method, dry thermal decomposition/calcination) or using a nonconventional energy source (i.e., microwave or ultrasonic treatment) to convert precursors into iron oxides. The resulting materials were

• general, the procedure leading to metal oxide materials consists of the thermal decomposition of adequate precursors under different conditions: by classical heating at high temperature in air (calcination) or in solution, in presence of changing ligands or surfactants. Nonconventional energy sources such

• reactions by the solvothermal method, it was demonstrated that the size and shape of the obtained nanoparticles is highly sensitive to the concentration of surfactants. By changing the solvent, the reaction outcome was not significantly affected. Calcination The simplest method used to obtain nanoparticles

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

• bands are typical for the νC–H stretching and δCH2 deformation vibration modes of –CH2– and CH3– groups belonging to the CTA+ ions, respectively. After the thermal treatment, these bands completely disappear from the infrared spectrum corroborating the whole removal of the organic species by calcination

• calcination under the same conditions but without assembling of ZnO NP (Table 1). Anyway, as it occurs with other related materials affected by delamination processes, the solids prepared here exhibit higher values of total porosity and specific surface area than ZnO-clay heterostructures, which is of

• before and after the calcination step (Figure 6d and Figure 6e). As occurs in the heterostructures derived from layered clays, here the presence of ZnO NP stabilized in the wurtzite phase (JCPDS 36-1451) is also observed. Interestingly, the calcination procedure here applied did not cause the complete

In situ formation of reduced graphene oxide structures in ceria by combined sol–gel and solvothermal processing

• Jingxia Yang,
• Johannes Ofner,
• Bernhard Lendl and
• Ulrich Schubert

Beilstein J. Nanotechnol. 2016, 7, 1815–1821, doi:10.3762/bjnano.7.174

• AC). After calcination, the surface area of rGO(0.05)–CeO2 was reduced from 256.3 to 55.5 m2/g and that of rGO(0)–CeO2 from 276.9 to 88.9 m2/g. The activity of rGO(0.05)–CeO2–AC is somewhat lower than that of rGO(0.05)-CeO2 at the same temperature, but still higher than that of rGO(0)–CeO2–AC. For

Prediction of the mechanical properties of zeolite pellets for aerospace molecular decontamination applications

• Guillaume Rioland,
• Patrick Dutournié,
• Delphine Faye,
• T. Jean Daou and
• Joël Patarin

Beilstein J. Nanotechnol. 2016, 7, 1761–1771, doi:10.3762/bjnano.7.169

• -lined stainless-steel autoclaves and heated at 150 °C for 2 days. After synthesis the product was filtered, washed with deionized water several times and dried overnight at 100 °C. The organic compounds were finally removed by calcination at 550 °C for 8 h in air (ramp at 1 °C·min−1). Methylcellulose

Surface roughness rather than surface chemistry essentially affects insect adhesion

• Matt W. England,
• Tomoya Sato,
• Makoto Yagihashi,
• Atsushi Hozumi,
• Stanislav N. Gorb and
• Elena V. Gorb

Beilstein J. Nanotechnol. 2016, 7, 1471–1479, doi:10.3762/bjnano.7.139

• samples underwent thermal calcination in air for 3 h at 600 °C in order to remove any organic components, and thus obtain SiO2 nanostructures. After VUV irradiation at 103 Pa for 30 min, the samples were finally exposed to a FAS17-Cl vapor at room temperature (25 ± 2 °C) for more than 3 h under reduced

Ammonia gas sensors based on In₂O₃/PANI hetero-nanofibers operating at room temperature

• Qingxin Nie,
• Zengyuan Pang,
• Hangyi Lu,
• Yibing Cai and
• Qufu Wei

Beilstein J. Nanotechnol. 2016, 7, 1312–1321, doi:10.3762/bjnano.7.122

• electrospinning, and then hollow structure indium oxide (In2O3) nanofibers were obtained through calcination with PVP as template material. In situ polymerization was used to prepare indium oxide/polyaniline (In2O3/PANI) composite nanofibers with different mass ratios of In2O3 to aniline. The structure and

• [21][23][24][25][26][27]. In this paper, In2O3/PANI composite nanofibers were prepared by the combination of electrospinning technique, calcination method and in situ polymerization. This study presents the improved response capabilities of gas sensors based on In2O3/PANI composite nanofibers, which

• calcination was In2O3. The chemical structure of the precursor nanofibers, In2O3 nanofibers and In2O3/PANI nanofibers were analyzed by FTIR. As shown in Figure 2b, the FTIR spectrum of In(NO3)3/PVP composite nanofibers exhibits a broad characteristic band around 3382 cm−1, which is related to the O–H

Mesoporous hollow carbon spheres for lithium–sulfur batteries: distribution of sulfur and electrochemical performance

• Anika C. Juhl,
• Artur Schneider,
• Boris Ufer,
• Torsten Brezesinski,
• Jürgen Janek and
• Michael Fröba

Beilstein J. Nanotechnol. 2016, 7, 1229–1240, doi:10.3762/bjnano.7.114

• another 18 h at room temperature, the suspension was neutralized with hydrochloric acid (32%) to precipitate the core–shell particles. The precipitate was centrifuged and dried at 60 °C before removing the surfactant by calcination at 550 °C for 6 h in air. Synthesis of hollow carbon spheres The synthesis

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

• Engineering, Tianjin University of Technology, Tianjin 300384, China 10.3762/bjnano.7.69 Abstract A series of NaTaO3 photocatalysts were prepared with Ta2O5 and NaOH via a hydrothermal method. CuO was loaded onto the surface of NaTaO3 as a cocatalyst by successive impregnation and calcination. The obtained

Microwave solvothermal synthesis and characterization of manganese-doped ZnO nanoparticles

• Jacek Wojnarowicz,
• Roman Mukhovskyi,
• Elzbieta Pietrzykowska,
• Sylwia Kusnieruk,
• Jan Mizeracki and
• Witold Lojkowski

Beilstein J. Nanotechnol. 2016, 7, 721–732, doi:10.3762/bjnano.7.64

• ., formation of clusters [31]), the precipitation of foreign phases [33][34], the stoichiometry; the presence of oxygen vacancies [35][36], and defects of the crystalline lattice. When the synthesis or calcination of Zn1−xMnxO was carried out in an oxidising environment and the absence of foreign phases was

• ]. But when a reducing environment was selected for sample calcination, also precipitations of ZnMnO3 and ZnMn2O4 phase emerged in Zn1−xMnxO and the material displayed only ferromagnetic properties [36]. Ferromagnetic properties of Zn1−xMnxO are explained by the presence of oxygen vacancies, manganese in

• preparation. This explains the various reports about obtaining Zn1−xMnxO with different and in parts contradictory properties. The relevant literature describes several methods for the synthesis of Zn1−xMnxO nanomaterials, in particular coprecipitation [49], coprecipitation–calcination [29][50][51

Cantilever bending based on humidity-actuated mesoporous silica/silicon bilayers

• Christian Ganser,
• Gerhard Fritz-Popovski,
• Roland Morak,
• Parvin Sharifi,
• Benedetta Marmiroli,
• Barbara Sartori,
• Heinz Amenitsch,
• Thomas Griesser,
• Christian Teichert and
• Oskar Paris

Beilstein J. Nanotechnol. 2016, 7, 637–644, doi:10.3762/bjnano.7.56

• samples for the water-sorption-induced deformation of the silica films [20]. Even much stronger deformation is expected during drying and calcination of the as synthesized films, causing the pore lattice to strongly shrink in the direction perpendicular to the substrate, while it is kept almost constant

• contingent at the SAXS beamline. We thank B. Sartory (Materials Center Leoben) for FIB sample preparation and for SEM measurements, and E. Bucher (Chair of Physical Chemistry, Montanuniversitaet Leoben) for the calcination of the samples.

Selective porous gates made from colloidal silica nanoparticles

• Roberto Nisticò,
• Paola Avetta,
• Paola Calza,
• Debora Fabbri,
• Giuliana Magnacca and
• Dominique Scalarone

Beilstein J. Nanotechnol. 2015, 6, 2105–2112, doi:10.3762/bjnano.6.215

• reverse micellization takes place, reverse micelles can work as nanoreactors [40] and used to produce nanoparticles. Basing on our results, the reverse micellization regime definitively establishes with a TEOS/block copolymer weight ratio of 75/25 and the corresponding samples, obtained after calcination

• range 1–2 nm, probably due to intraparticle voids generated from the elimination of poly(ethylene-oxide) moieties during the calcination step [41]. Transport testing of the functional coating UV–vis spectroscopy was used to study the diffusion of two positively charged chemical probes (i.e., MB and

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

• titanium dioxide grown on soda lime glass (SLG) occurs during the calcination step and is due to the diffusion of alkali elements (especially sodium ions, Na+) [3][4]. Usually, TiO2 is amorphous when deposited at low temperature [5][6]. Heat treatment at a higher temperature (around 450 °C) is usually

• shows SEM images highlighting the TiO2 film morphology resulting from the sol–gel process and calcination at 450 °C for an increasing SiNx barrier thickness. The surface of the film resulting from the sol−gel method was uniform. The average grain size was about 30−50 nm when a TiO2 film was directly

• 450 °C are presented in Figure 3 and Figure 4. It is worth noting that the films, as deposited on SLG or on SiNx/SLG systems, are amorphous regardless of the deposition method. After the calcination step, TiO2 grown on SLG is crystallized in the anatase structure regardless of the method and the SiNx

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

• neutral environment at 200 °C. Scanning electron microscopy investigations showed that the hydrothermal processing significantly affected the nanoribbon surfaces, which became rougher, while the transformations based on calcination in either oxidative or reductive atmospheres had no effect on the

• morphology or on the surface appearance of the nanoribbons. The transformations performed in the reductive atmosphere, an NH3(g)/Ar(g) flow, and in the ammonia solution led to nitrogen doping. The nitrogen content increased with an increasing calcination temperature, as was determined by X-ray photoelectron

• spectroscopy. According to electron paramagnetic resonance measurements the calcination in the reductive atmosphere also resulted in a partial reduction of Ti4+ to Ti3+. The photocatalytic performance of the derived TiO2 NRs was estimated on the basis of the photocatalytic oxidation of isopropanol. After

Tunable white light emission by variation of composition and defects of electrospun Al₂O₃–SiO₂ nanofibers

• Jinyuan Zhou,
• Gengzhi Sun,
• Hao Zhao,
• Xiaojun Pan,
• Zhenxing Zhang,
• Yujun Fu,
• Yanzhe Mao and
• Erqing Xie

Beilstein J. Nanotechnol. 2015, 6, 313–320, doi:10.3762/bjnano.6.29

• Avenue, 639798, Singapore 10.3762/bjnano.6.29 Abstract Composite nanofibers consisting of Al2O3–SiO2 were prepared by electrospinning in combination with post-calcination in air. X-ray diffraction, scanning electron microscopy, and transmission electron microscopy were used to investigate the

• )–O–C∙=O) formed on the pore surface [16]. Mir et al. incorporated 30 nm, Al2O3 nanocrystals into silica aerogels, followed by calcination at 1150 °C in air for 2 h. The resulting 1Al2O3–3SiO2 composites exhibited strong, visible PL bands ranging from 400 to 600 nm centered at ≈500 nm, which were

• . Thus, it is important and instructive to further explore the preparation and PL properties of these environmentally friendly, Al2O3–SiO2 nanomaterials. In this work, Al2O3–SiO2 composite nanofibers with different Al/(Al–Si) ratios were prepared by electrospinning in combination with calcination in air

Manganese oxide phases and morphologies: A study on calcination temperature and atmospheric dependence

• Matthias Augustin,
• Daniela Fenske,
• Ingo Bardenhagen,
• Anne Westphal,
• Martin Knipper,
• Thorsten Plaggenborg,
• Joanna Kolny-Olesiak and
• Jürgen Parisi

Beilstein J. Nanotechnol. 2015, 6, 47–59, doi:10.3762/bjnano.6.6

• such as particle size, surface area and Mnx+ oxidation state is required. Here, Mn3O4 and Mn5O8 nanoparticles as well as mesoporous α-Mn2O3 particles were synthesized by calcination of Mn(II) glycolate nanoparticles obtained through an economical route based on a polyol synthesis. The preparation of

• the calcination temperature and the presence of an oxidizing or neutral atmosphere. Furthermore, to demonstrate the application potential of the synthesized MnOx species, we studied their catalytic activity for the oxygen reduction reaction in aprotic media. Linear sweep voltammetry revealed the best

• manganese oxide compounds can be prepared via calcination processes from suitable precursors [7][18][19][20]. Whereas many synthetic protocols yield manganese oxide species at the nanometer scale [21], for example, precipitation or the solvothermal route, these methods require long reaction times in the

Synthesis and characterization of fluorescence-labelled silica core-shell and noble metal-decorated ceria nanoparticles

• Rudolf Herrmann,
• Markus Rennhak and
• Armin Reller

Beilstein J. Nanotechnol. 2014, 5, 2413–2423, doi:10.3762/bjnano.5.251

• is a common technique for the preparation of heterogeneous catalysts. It generally involves impregnation of the carrier with a soluble precursor and calcination, or precipitation and reduction followed in most cases by calcination which is expected to increase the fixation of the metal on the carrier

• in the light of the observed increase in agglomeration after calcination of ceria NP (see above) some caution is justified when the preparation calls for this technique. Several approaches to noble-metal-decorated ceria NP have been suggested recently: for gold and palladium by reduction [48][54][55

• ], and for gold and platinum by microwave-assisted reduction [56]. In order to prevent agglomeration during calcination of Pt/CeO2 hybrid particles, a procedure was reported that adds H2PtCl6 to ceria NP, followed by gel/sol formation with TEOS, calcination and finally removal of the SiO2 protective

Biopolymer colloids for controlling and templating inorganic synthesis

• Laura C. Preiss,
• Katharina Landfester and
• Rafael Muñoz-Espí

Beilstein J. Nanotechnol. 2014, 5, 2129–2138, doi:10.3762/bjnano.5.222

• involves the deposition of an inorganic material on the surface of “hard” spheres (silica or polymer) that act as sacrificial cores. The core can be eventually removed by calcination or dissolution, if the aim is the formation of hollow structures. Such strategies have been widely used for templates with

• molybdenum oxide clusters, which were shown to be active as catalysts for selective alcohol oxidation. Similarly, Ganesan and Gedanken [74] had prepared tungsten(VI) oxide nanoparticles through the encapsulation of ammonium metatungstate on chitosan and the subsequent calcination. These particles showed a

• supercritical CO2 and subsequent calcination. Scaffold templating can also be achieved with starch and even with peptides. Thakore et al. [13] synthesized Cu, Ag, and Cu–Ag alloy nanoparticles in a matrix of starch through a green route and studied the antibacterial activity. Hexagonal silica platelets were

Carbon nano-onions (multi-layer fullerenes): chemistry and applications

• Juergen Bartelmess and
• Silvia Giordani

Beilstein J. Nanotechnol. 2014, 5, 1980–1998, doi:10.3762/bjnano.5.207

• synthesized in situ from nickel nitrate hexahydrate and ammoniumhydroxide in ethanol in the presence of (4-dimethylamino)pyridine (4-DMAP) as modifier in a one-pot multi-step reaction. Calcination of the CNO/4-DMAP/Ni(OH)2 composite led to the CNO/4-DMAP/NiO composite material. The electrochemical properties

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

• mean wavelength of 500 nm is reasonable to assume. Therefore, a mean pigment size of 250 nm is close to what the titanium dioxide makers are producing. The calcination temperature, as the final step of the powder synthesis of the sulfate process, gives the choice of producing either the low-temperature

Nanoporous composites prepared by a combination of SBA-15 with Mg–Al mixed oxides. Water vapor sorption properties

• Amaury Pérez-Verdejo,
• Alvaro Sampieri,
• Heriberto Pfeiffer,
• Mayra Ruiz-Reyes,
• Juana-Deisy Santamaría and
• Geolar Fetter

Beilstein J. Nanotechnol. 2014, 5, 1226–1234, doi:10.3762/bjnano.5.136

• basic pH, as SiO2 is not formed. Furthermore, during calcination, the nanocasting of Mg–Al species can occur on the mesoporous surface of the SBA-15 [9]. Indeed, the Mg–Al hydrotalcite becomes a magnesium–aluminum mixed oxide (Mg–Al–O) nanoparticles with thermal treatment and the average wall thickness

• microporous blocked by Mg–Al–O particles and the calcination process. As N2 adsorption–desorption isotherms of HT/SBA (C) and HT/SBA (NC) composites and SBA-15 present similar profile curves (Figure 1), they can also be structurally analogous and such profiles indicate no mesoporous blocking. The resulting

• , the XRD patterns of composites also show a broad peak (15–30° 2θ) analogous to the amorphous SiO2 from SBA-15. Therefore, after calcination, the Mg–Al mixed oxides may be homogeneously dispersed without particle sintering on the surface of SBA-15. A similar result was reported by Mao et al. in a

Template-directed synthesis and characterization of microstructured ceramic Ce/ZrO₂@SiO₂ composite tubes

• Jörg J. Schneider and
• Meike Naumann

Beilstein J. Nanotechnol. 2014, 5, 1152–1159, doi:10.3762/bjnano.5.126

• (PS)/SiO2 composite fibers. These composite fibers were subsequently covered by spray-coating with ceria and zirconia sol solutions. After drying and final calcination of the green body composites, the PS polymer template was removed, and composite tubes of the composition CeO2/ZrO2@SiO2 were obtained

• followed by the addition of ceria and zirconia nanoparticles, both of which are obtained from stable sol solutions by spray-coating onto the former material. The overall process yields ceramic microtubes of the composition Ce0.13/Zr0.87O2@SiO2 after calcination when a 1:7 molar ratio of Ce:Zr was employed

• particles to the PS surface. Calcination removes the PS fiber template the silica particles are attached to and subsequently converts the dense composite fiber morphology into a hollow tubular structure, which results in the formation of pure silica tubes. Figure 1 shows SEM images of the pure polymer PS

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

• (1) was isolated. When 1 was subjected to further hydrolysis it yielded nanoparticles of tantalum oxide after calcination at 750 °C for four hours. The photocatalytic activity of Ta2O5 nanoparticles was studied over the degradation of organic dye rhodamine B (RhB). Results and Discussion Tantalum

• rhodamine B (Figure 14). Moreover, the metal oxide particles agglomerate at acidic pH and hence the surface available for dye absorbance as well as the photon absorption is reduced. Effect of calcination temperature As-synthesized Ta2O5 powder was calcined in at 650 °C, 700 °C, 750 °C, and 800 °C. It was

• observed that Ta2O5 particles calcined at 750 °C possess best degradation efficiency (Figure 15). This may be due to increase in crystallinity and surface area with more active sites for photodegradation process when temperature is increased from 650 °C to 750 °C. A further increase in calcination