Size-dependent density of zirconia nanoparticles

• Agnieszka Opalinska,
• Iwona Malka,
• Wojciech Dzwolak,
• Tadeusz Chudoba,
• Adam Presz and
• Witold Lojkowski

Beilstein J. Nanotechnol. 2015, 6, 27–35, doi:10.3762/bjnano.6.4

• 10.3762/bjnano.6.4 Abstract The correlation between density and specific surface area of ZrO2 nanoparticles (NPs) was studied. The NPs were produced using a hydrothermal process involving microwave heating. The material was annealed at 1100 °C which resulted in an increase in the average grain size of the

• effect of the surface layer on the NP density becomes particularly evident for NPs smaller than 50 nm, and thus, the density of nanoparticles is size dependent. Keywords: density; hydrothermal synthesis; hydroxy groups; nanometrology; nanopowders; zirconia; Introduction Zirconium oxide (ZrO2) has a

• up to 1100 °C and transforms to t-ZrO2, which exists in the temperature range 1100–2370 °C, while the cubic phase is found above 2370 °C [21]. However, for nanocrystalline powders, the tetragonal phase can be obtained directly during hydrothermal synthesis. It was previously observed that density

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

• -containing solutions [34] it was found that structures obtained by thermal evaporation (such as sample 3) generally dissolved slower than those from hydrothermal processes. This observation is only partially applicable to the nanoparticles studied. Within one day all ZnO-NP were completely destroyed by the

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

• Co3O4 electrodes. They observed, for example, an increase of the specific capacity from 190 mA·h·g−1 to 632 mA·h·g−1 at a current density of 200 mA·g−1 and also an increased rate capability [64]. In the latter report, the CNO hybrid material was prepared from KMnO4 and CNOs by a hydrothermal method

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

• -precipitation for the preparation of powders [13], impregnation [9], dip-coating [5], or hydrothermal synthesis [4], sol–gel synthesis routes have been widely employed for the preparation of CexZr1−xO2 solid solutions [14]. Pure aqueous sols or sols stabilized by the addition of organics, e.g., surfactants

Functionalized nanostructures for enhanced photocatalytic performance under solar light

• Liejin Guo,
• Dengwei Jing,
• Maochang Liu,
• Yubin Chen,
• Shaohua Shen,
• Jinwen Shi and
• Kai Zhang

Beilstein J. Nanotechnol. 2014, 5, 994–1004, doi:10.3762/bjnano.5.113

• cocatalyst. A simple hydrothermal method was used to synthesize NiS/CdS photocatalysts, which have a remarkably high QE of 51.3% at 420 nm in lactic acid sacrificial solution [27]. Co-loading of both reduction and oxidation cocatalysts on the semiconductor was also suggested to be able to enhance the

• simple one-step hydrothermal method [33]. As schematically illustrated in Figure 5, the CdS nanoparticle was intimately enwrapped by the TNTs, resulting in a remarkably enhanced charge separation efficiency and thereby photocatalytic hydrogen production activity. The similar enwrapped structure can also

• a big challenge to date. Selecting Cu2WS4 as model photocatalyst, we obtained interesting decahedral morphologies by a one-step hydrothermal method. The hydrothermal method avoids the using of toxic H2S gas and simplifies the catalyst preparation process. Owing to the oriented growth and the

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

• the recent progress achieved in these areas is reviewed here. ALD growth of CNT–TiO2 Many methods have been developed to fabricate CNT–metal/metal oxide nanocomposites. For CNT–TiO2, the methods that are mostly adopted are sol–gel and hydrothermal deposition. A good summary of the synthesis methods

Nanostructure sensitization of transition metal oxides for visible-light photocatalysis

• Hongjun Chen and
• Lianzhou Wang

Beilstein J. Nanotechnol. 2014, 5, 696–710, doi:10.3762/bjnano.5.82

• resistance to photobleaching. Up to now, many methods [112][113][114][115][116][117][118][119][120][121][122][123][124][125][126][127] are available for the fabrication of carbon nanodots, for instance, the electrochemical method, the microwave method, the ultrasonic method, the hydrothermal method. Due to

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

• 10.3762/bjnano.5.77 Abstract Silver chromate (Ag2CrO4) photocatalysts are prepared by microemulsion, precipitation, and hydrothermal methods, in order to investigate the effect of preparation methods on the structure and the visible-light photocatalytic activity. It is found that the photocatalytic

• . Considering the universalities of microemulsion, precipitation, and hydrothermal methods, this work may also provide a prototype for the comparative study of semiconductor based photocatalysis for water purification and environmental remediation. Keywords: microemulsion method; nanoparticles; photocatalysis

• -micellar [44], hydrothermal [45], sonochemical [41], and template methods [46]. It is known that the photocatalytic activity of semiconductor photocatalysts relies heavily on their structures, which are commonly determined by the preparation methods [47][48][49]. Nevertheless, to our knowledge, there is no

Enhanced photocatalytic activity of Ag–ZnO hybrid plasmonic nanostructures prepared by a facile wet chemical method

• Sini Kuriakose,
• Vandana Choudhary,
• Biswarup Satpati and
• Satyabrata Mohapatra

Beilstein J. Nanotechnol. 2014, 5, 639–650, doi:10.3762/bjnano.5.75

• nanocomposites have a larger surface area as compared to ZnO, which leads to enhanced adsorption of dye. Secondly, due to the decoration of ZnO with Ag nanoparticles, the recombination of electrons and holes are inhibited. Gao et al. [42] synthesized Ag–ZnO nanocomposites by a biomolecule assisted hydrothermal

High activity of Ag-doped Cd_0.1Zn_0.9S photocatalyst prepared by the hydrothermal method for hydrogen production under visible-light irradiation

• Leny Yuliati,
• Melody Kimi and
• Mustaffa Shamsuddin

Beilstein J. Nanotechnol. 2014, 5, 587–595, doi:10.3762/bjnano.5.69

• -University Studies, Universiti Malaysia Sarawak, 94300 Kota Samarahan, Sarawak, Malaysia 10.3762/bjnano.5.69 Abstract Background: The hydrothermal method was used as a new approach to prepare a series of Ag-doped Cd0.1Zn0.9S photocatalysts. The effect of Ag doping on the properties and photocatalytic

• activity of Cd0.1Zn0.9S was studied for the hydrogen production from water reduction under visible light irradiation. Results: Compared to the series prepared by the co-precipitation method, samples prepared by the hydrothermal method performed with a better photocatalytic activity. The sample with the

• Cd0.1Zn0.9S photocatalyst. Keywords: Ag doping; Cd0.1Zn0.9S; hydrogen production; hydrothermal; visible light; Introduction The development of clean and renewable hydrogen energy through a sustainable production process is still a big issue to be addressed. Solar energy is a very attractive option as it is

Nanoscale particles in technological processes of beneficiation

• Sergey I. Popel,
• Vitaly V. Adushkin and
• Anatoly P. Golub'

Beilstein J. Nanotechnol. 2014, 5, 458–465, doi:10.3762/bjnano.5.53

• cavitation bubbles. On the basis of this theory, the maximum dimensions of cavitation bubbles were estimated, as well as the size of globules generated due to the melting of particles of different mineral composition under cavitation effects in hydrothermal fluids. It was shown that the cavitation mechanism

• may bring about the formation of mineral and metallic nanospherules in hydrothermal fluids. The formation of nano- and microspherules with regard to the depth of host rock was also investigated. In [11] the possible cavitation disintegration of polymineral microparticles placed into a liquid as a

One-step synthesis of high quality kesterite Cu₂ZnSnS₄ nanocrystals – a hydrothermal approach

• Vincent Tiing Tiong,
• John Bell and
• Hongxia Wang

Beilstein J. Nanotechnol. 2014, 5, 438–446, doi:10.3762/bjnano.5.51

• synthesis of pure kesterite-phase Cu2ZnSnS4 (CZTS) nanocrystals with a uniform size distribution by a one-step, thioglycolic acid (TGA)-assisted hydrothermal route. The formation mechanism and the role of TGA in the formation of CZTS compound were thoroughly studied. It has been found that TGA interacted

• with Cu2+ to form Cu+ at the initial reaction stage and controlled the crystal-growth of CZTS nanocrystals during the hydrothermal reaction. The consequence of the reduction of Cu2+ to Cu+ led to the formation Cu2−xS nuclei, which acted as the crystal framework for the formation of CZTS compound. CZTS

• was formed by the diffusion of Zn2+ and Sn4+ cations to the lattice of Cu2−xS during the hydrothermal reaction. The as-synthesized CZTS nanocrystals exhibited strong light absorption over the range of wavelength beyond 1000 nm. The band gap of the material was determined to be 1.51 eV, which is

Dye-sensitized Pt@TiO₂ core–shell nanostructures for the efficient photocatalytic generation of hydrogen

• Jun Fang,
• Lisha Yin,
• Shaowen Cao,
• Yusen Liao and
• Can Xue

Beilstein J. Nanotechnol. 2014, 5, 360–364, doi:10.3762/bjnano.5.41

• hydrothermal method. The dye-sensitization of these Pt@TiO2 core–shell structures allows for a high photocatalytic activity for the generation of hydrogen from proton reduction under visible-light irradiation. When the dyes and TiO2 were co-excited through the combination of two irradiation beams with

• Discussion The Pt@TiO2 core–shell nanoparticles were prepared trough a hydrothermal process by using Pt nanoparticles and TiF4 as the precursor. The crystalline structure was determined by XRD, as shown in Figure 1. After the hydrothermal reaction, the TiO2 was transformed into anatase phase, which could be

• . This indicates the retaining of the Pt nanoparticle cores after the hydrothermal reaction. As a control sample, Pt/TiO2 was prepared through the photodeposition of Pt (1% in mole fraction) onto pure TiO2 particles that were prepared through the same hydrothermal method without using Pt nanoparticles

Photovoltaic properties of ZnO nanorods/p-type Si heterojunction structures

• Rafal Pietruszka,
• Bartlomiej S. Witkowski,
• Grzegorz Luka,
• Lukasz Wachnicki,
• Sylwia Gieraltowska,
• Krzysztof Kopalko,
• Eunika Zielony,
• Piotr Bieganski,
• Ewa Placzek-Popko and
• Marek Godlewski

Beilstein J. Nanotechnol. 2014, 5, 173–179, doi:10.3762/bjnano.5.17

• , Wroclaw, Poland Department of Mathematics and Natural Sciences College of Science, Cardinal Stefan Wyszynski University, Warsaw, Poland 10.3762/bjnano.5.17 Abstract Selected properties of photovoltaic (PV) structures based on n-type zinc oxide nanorods grown by a low temperature hydrothermal method on p

• the structure containing closely-spaced nanorods, which show light conversion efficiency of 3.6%. Keywords: atomic layer deposition; hydrothermal method; solar cells; zinc oxide; zinc oxide nanorods; Introduction Solar cells are intensively studied as an alternative energy source and may replace

• on zinc oxide nanorods grown by a hydrothermal method on top of p-type Si, covered on top with ZnO:Al films grown by atomic layer deposition (ALD) and acting as a transparent electrode. These simple and low costs solar cells show a power conversion efficiency, which we consider satisfactory

Preparation of NiS/ZnIn₂S₄ as a superior photocatalyst for hydrogen evolution under visible light irradiation

• Liang Wei,
• Yongjuan Chen,
• Jialin Zhao and
• Zhaohui Li

Beilstein J. Nanotechnol. 2013, 4, 949–955, doi:10.3762/bjnano.4.107

• successfully prepared via a facile two-step hydrothermal process. The as-prepared samples were characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM) and high-resolution transmission electron microscopy (HRTEM). Their photocatalytic performance

• step hydrothermal processes is beneficial for the directional migration of the photo-excited electrons from ZnIn2S4 to NiS. The highest photocatalytic hydrogen evolution rate (104.7 μmol/h), which is even higher than that over Pt/ZnIn2S4 nanocomposite (77.8 μmol/h), was observed over an optimum NiS

• visible light. ZnIn2S4 is a ternary chalcogenide with a suitable band gap (2.34–2.48 eV) well corresponding to the visible light absorption. ZnIn2S4 exhibits two distinct polymorphs based on cubic and hexagonal lattices [16], which can be controlled synthesized via a facile hydrothermal method using

A facile synthesis of a carbon-encapsulated Fe₃O₄ nanocomposite and its performance as anode in lithium-ion batteries

• Raju Prakash,
• Katharina Fanselau,
• Shuhua Ren,
• Tapan Kumar Mandal,
• Christian Kübel,
• Horst Hahn and
• Maximilian Fichtner

Beilstein J. Nanotechnol. 2013, 4, 699–704, doi:10.3762/bjnano.4.79

• strategies, such as carbon coatings [7], carbon core–shells [8], nanocomposites [9], nanostructures [10], or nano-encapsulation [11], have recently been explored to circumvent this problem. These strategies apply various synthetic methods [12] such as hydrothermal, coprecipitation, microemulsion, sol–gel

Towards atomic resolution in sodium titanate nanotubes using near-edge X-ray-absorption fine-structure spectromicroscopy combined with multichannel multiple-scattering calculations

• Carla Bittencourt,
• Peter Krüger,
• Maureen J. Lagos,
• Xiaoxing Ke,
• Gustaaf Van Tendeloo,
• Chris Ewels,
• Polona Umek and
• Peter Guttmann

Beilstein J. Nanotechnol. 2012, 3, 789–797, doi:10.3762/bjnano.3.88

• hydrothermal process used to synthesize the tubes, the binding energy of Ti 2p photoemission lines are shifted slightly to lower binding energy, showing that the local environment around the Ti ions in the (Na,H)TiNTs is different from that in the anatase-type TiO2 (see also Supporting Information File 1

• , Figure S1). The absence of extra peaks or broadening of the Ti 2p photoemission lines suggest that the chemical environment of the Ti ions does not change during the hydrothermal treatment of TiO2. The Ti L-edge shows two groups of peaks arising from the spin-orbit splitting of the Ti 2p core level into

• resolution of NEXAFS–TXM towards the atomic limit. Experimental Materials Sodium titanate nanotubes ((Na,H)TiNTs) were synthesized from anatase TiO2 (Aldrich, –325 mesh), and 10 M NaOH(aq) under hydrothermal conditions at 135 °C. The anatase (Aldrich, –325 mesh), and SrTiO3 (Alfa Aesar) were used as standard

Paper modified with ZnO nanorods – antimicrobial studies

• Mayuree Jaisai,
• Sunandan Baruah and
• Joydeep Dutta

Beilstein J. Nanotechnol. 2012, 3, 684–691, doi:10.3762/bjnano.3.78

• in cellular internalization of ZnO nanoparticles has also been observed by Appierot et al. [6] in a study of their antibacterial effect on E. coli and S. aureus. This work reports on an antimicrobial paper containing zinc oxide (ZnO) nanorods grown by a hydrothermal process, and which can be used for

• of organic dyes using similar paper embedded with ZnO nanorods [21]. In this work we report the antimicrobial activities of paper functionalized by in situ growth of ZnO nanorods through a hydrothermal process. Results and Discussion Studies on the photocatalytic immobilization of E. coli and S

• tissue papers. Conclusion Antimicrobial paper has been successfully prepared by growing ZnO nanorods on paper prepared from bleached soft wood kraft pulp by using a simple hydrothermal process at low temperature. The antimicrobial paper inhibits the growth of harmful microbes due to a slow release of

Distribution of functional groups in periodic mesoporous organosilica materials studied by small-angle neutron scattering with in situ adsorption of nitrogen

• Monir Sharifi,
• Dirk Wallacher and
• Michael Wark

Beilstein J. Nanotechnol. 2012, 3, 428–437, doi:10.3762/bjnano.3.49

• higher hydrothermal stability. The functionalization of the benzene-PMO was realized by grafting, using surface silanol groups as well as benzene rings to anchor the SO3H-groups [27]. Scheme 1 shows a sketch of the studied SO3H- or SO3− sulfonate groups pointing into the channels and the protons hopping

Reduced electron recombination of dye-sensitized solar cells based on TiO₂ spheres consisting of ultrathin nanosheets with [001] facet exposed

• Hongxia Wang,
• Meinan Liu,
• Cheng Yan and
• John Bell

Beilstein J. Nanotechnol. 2012, 3, 378–387, doi:10.3762/bjnano.3.44

• magnetic stirring of the mixture of the three components at room temperature. The precursor solution was then transferred to a Teflon-lined stainless steel autoclave (45 mL volume, Parr Instrument Co.) for the hydrothermal reaction. The hydrothermal process was carried out at 200 °C for 24 h in an electric

Synthesis and catalytic applications of combined zeolitic/mesoporous materials

• Jarian Vernimmen,
• Vera Meynen and
• Pegie Cool

Beilstein J. Nanotechnol. 2011, 2, 785–801, doi:10.3762/bjnano.2.87

• accommodate many different heteroelements (other than Si and O). Their remarkable stability (mechanical, hydrothermal, thermal and chemical) and high catalytic activity and (shape) selectivity make zeolites unique materials. However, despite these wonderful properties, zeolites have one major drawback: Their

• mesopores in zeolites is dealumination [64]. By subjecting Al-containing zeolites to a hydrothermal treatment (steaming) and/or acid leaching, the Si–O–Al bonds are hydrolyzed, resulting in a partial destruction of the silicate framework. The dealumination process occurs randomly and depends highly on the

• [73][74] or a microtemplate [75][76], and subjected to a hydrothermal treatment. This results in dissolution of the silica, which will then interact with the template and recrystallize in a mesoporous or zeolitic phase depending on the added template. The degree of crystallinity or mesoporosity can be

Template-assisted formation of microsized nanocrystalline CeO₂ tubes and their catalytic performance in the carboxylation of methanol

• Jörg J. Schneider,
• Meike Naumann,
• Christian Schäfer,
• Armin Brandner,
• Heiko J. Hofmann and
• Peter Claus

Beilstein J. Nanotechnol. 2011, 2, 776–784, doi:10.3762/bjnano.2.86

• polymer-templating method was investigated in an effort to reduce such agglomeration [1][7][8][9][10][11]. Nanosized ceria can be synthesized by methods such as chemical vapour deposition (CVD), spray pyrolysis, hydrothermal synthesis or electrosynthesis [1][2][9]. These approaches lead to particulate

Highly efficient ZnO/Au Schottky barrier dye-sensitized solar cells: Role of gold nanoparticles on the charge-transfer process

• Tanujjal Bora,
• Htet H. Kyaw,
• Soumik Sarkar,
• Samir K. Pal and
• Joydeep Dutta

Beilstein J. Nanotechnol. 2011, 2, 681–690, doi:10.3762/bjnano.2.73

• hexamethylenetetramine (C6H12N4, Aldrich) were used as starting materials for the growth of the ZnO nanorods. A low-temperature hydrothermal process was used for the ZnO-nanorod growth. Detailed processes for the hydrothermal growth of the single crystalline ZnO nanorods are described in our previous reports [9][37][38

Investigation on structural, thermal, optical and sensing properties of meta-stable hexagonal MoO₃ nanocrystals of one dimensional structure

• Angamuthuraj Chithambararaj and
• Arumugam Chandra Bose

Beilstein J. Nanotechnol. 2011, 2, 585–592, doi:10.3762/bjnano.2.62

• [4]. By adjusting the hydrothermal reaction temperature, metastable (h-MoO3) and stable (α-MoO3) MoO3 nanoparticles were successfully synthesized by Chithambararaj et al. [15]. Thus, many research articles are focused on the synthesis of h-MoO3 as opposed to the stable α-MoO3, due to the reduced

Inorganic–organic hybrid materials through post-synthesis modification: Impact of the treatment with azides on the mesopore structure

• Miriam Keppeler,
• Jürgen Holzbock,
• Johanna Akbarzadeh,
• Herwig Peterlik and
• Nicola Hüsing

Beilstein J. Nanotechnol. 2011, 2, 486–498, doi:10.3762/bjnano.2.52

• [18]. Each of these strategies allows for a high level of control over macropore/mesopore size distribution, surface area, etc. It is well known that ageing of silica gels in different environments or in hydrothermal conditions has a pronounced influence on the final gel structure [19][20]. Ageing at

• alkaline solutions and hydrothermal conditions, from amorphous mesoporous materials to well-organized mesoporous structures [22][23]. Many silica gels are functionalized by organic groups specific for their eventual applications. Typical examples are the hydrophobization with methyl or phenyl groups, and