Recent progress in actuation technologies of micro/nanorobots

• Ke Xu and
• Bing Liu

Beilstein J. Nanotechnol. 2021, 12, 756–765, doi:10.3762/bjnano.12.59

• FRET imaging while propelling the switches. The entire self-actuation process is realized by urease-mediated conversion of urea into ammonia and carbon dioxide. Unlike traditional nanoprobes, DNA nanoswitches can perform pH value measurements within a few microseconds. This research is a big step

Impact of GaAs(100) surface preparation on EQE of AZO/Al₂O₃/p-GaAs photovoltaic structures

• Piotr Caban,
• Rafał Pietruszka,
• Jarosław Kaszewski,
• Monika Ożga,
• Bartłomiej S. Witkowski,
• Krzysztof Kopalko,
• Piotr Kuźmiuk,
• Katarzyna Gwóźdź,
• Ewa Płaczek-Popko,
• Krystyna Lawniczak-Jablonska and
• Marek Godlewski

Beilstein J. Nanotechnol. 2021, 12, 578–592, doi:10.3762/bjnano.12.48

• μm2 for every sample), the lowest RMS values are observed in A4 and B4 samples: 2.05 and 1.96 nm, respectively (those samples were treated with the ammonia aqueous solution during stage 3). Conversely, the highest roughness is observed in samples in which the HCl solution was applied (also during

Effect of different silica coatings on the toxicity of upconversion nanoparticles on RAW 264.7 macrophage cells

• Cynthia Kembuan,
• Helena Oliveira and
• Christina Graf

Beilstein J. Nanotechnol. 2021, 12, 35–48, doi:10.3762/bjnano.12.3

• measurements (TraceCERT®, c = 1000 mg/mL) were obtained from Sigma-Aldrich. Cyclohexane (tech. 99.5%) and ammonia water (p.a., 25 wt % NH3) were purchased from Roth. Ethanol (EtOH, 100%) was purchased from Berkel AHK, hydrofluoric acid (HF, 30%) was purchased from Riedel de Haën, and sodium hydroxide (NaOH, 99

• 33.3 mL of cyclohexane was used. After sonicating for 10 min, 3.736 mL of Igepal CO-520 was added. After a brief mixing using an ultrasonic bath, 0.331 mL of ammonia water was added, and the dispersion was sonicated again for 20 min. Subsequently, 0.331 mL of TEOS was added and the whole mixture was

• sonicated for at least 1 h. Finally, the dispersion was stirred for 12 h at 1200 rpm at room temperature [38]. For growing 21 ± 2 nm thick silica shells, additional cyclohexane, Igepal CO-520, and ammonia water were added to the non-purified dispersion of UCNPs coated with 7 ± 1 nm thick shells to maintain

Towards 3D self-assembled rolled multiwall carbon nanotube structures by spontaneous peel off

• Jonathan Quinson

Beilstein J. Nanotechnol. 2020, 11, 1865–1872, doi:10.3762/bjnano.11.168

• see Experimental section. Undoped sections of multiwall CNTs (MWCNTs) grown from toluene or acetylene, are referred as “C” whereas nitrogen-doped sections, grown under ammonia-containing atmosphere or using benzylamine, are referred as “N” [21]. The chronological order of the grown sections is shown

• second precursor line, 500 sccm of Ar were used. Next, while the same ferrocene and toluene mixture was injected into the furnace, ammonia (≥99.98%, BOC) was added to the carrier gas at 30 sccm for 15 min. Finally, acetylene (industrial grade, BOC) was used as a gas precursor at 100 sccm with hydrogen

Piezotronic effect in AlGaN/AlN/GaN heterojunction nanowires used as a flexible strain sensor

• Jianqi Dong,
• Liang Chen,
• Yuqing Yang and
• Xingfu Wang

Beilstein J. Nanotechnol. 2020, 11, 1847–1853, doi:10.3762/bjnano.11.166

• by MOCVD (Thomas Swan). Trimethylgallium (TMGa), trimethylaluminum (TMAl), and ammonia (NH3) were used as Ga, Al, and N sources, respectively. N2 and H2 were used as carrier gases in the growth process. A 1 μm layer of unintentionally doped GaN was deposited as the buffer layer on a sapphire

Unravelling the interfacial interaction in mesoporous SiO₂@nickel phyllosilicate/TiO₂ core–shell nanostructures for photocatalytic activity

• Bridget K. Mutuma,
• Xiluva Mathebula,
• Isaac Nongwe,
• Bonakele P. Mtolo,
• Boitumelo J. Matsoso,
• Rudolph Erasmus,
• Zikhona Tetana and
• Neil J. Coville

Beilstein J. Nanotechnol. 2020, 11, 1834–1846, doi:10.3762/bjnano.11.165

• /ammonia) [45][46][49]. In addition, the pore size distribution of the mSiO2@NiPS core–shell nanocomposite was broader (2–15 nm) than that of mSiO2 (Figure 2b). During the formation of the mSiO2@NiPS/TiO2 composite, the pore diameter slightly increased to 7.7 nm, indicating the presence of interparticle

• between NiPS and TiO2, which resulted in good stability and reusability of the catalyst. The generation of a core–shell nanostructure with tunable surface and optoelectronic properties is a promising approach for the production of efficient photocatalysts. Experimental Starting materials Ammonia solution

• nanoparticles were purchased from Sigma-Aldrich. Synthesis of mSiO2, mSiO2@NiPS and mSiO2@NiPS/TiO2 core–shell nanostructures Ethanol (100 mL) was added to 10 mL of water and the mixture was stirred for 10 min. A solution of 10 mL of ammonia was added to the co-solvents and the resultant mixture was stirred for

Electron beam-induced deposition of platinum from Pt(CO)₂Cl₂ and Pt(CO)₂Br₂

• Aya Mahgoub,
• Hang Lu,
• Rachel M. Thorman,
• Konstantin Preradovic,
• Titel Jurca,
• Lisa McElwee-White,
• Howard Fairbrother and
• Cornelis W. Hagen

Beilstein J. Nanotechnol. 2020, 11, 1789–1800, doi:10.3762/bjnano.11.161

• carbon content. In this way, water has been used for the purification of FEBID of platinum [33][34] and gold [35]. An analogous reaction occurs with ammonia to get rid of the halogen in deposits from the (η3-C3H5)Ru(CO)3Cl precursor [36]. However, this reaction scheme would lead to a much lower carbon

Selective detection of complex gas mixtures using point contacts: concept, method and tools

• Alexander P. Pospelov,
• Victor I. Belan,
• Dmytro O. Harbuz,
• Volodymyr L. Vakula,
• Lyudmila V. Kamarchuk,
• Yuliya V. Volkova and
• Gennadii V. Kamarchuk

Beilstein J. Nanotechnol. 2020, 11, 1631–1643, doi:10.3762/bjnano.11.146

• breath contains oxidizing agents (e.g., nitrogen oxides, carbon oxide, and sulfur oxides), reducing agents (e.g., hydrogen sulfide, ammonia, mercaptans, and organic molecules), and other chemically active components that can participate in various chemical transformations. It is known, for example, that

• hydrochloric acid interacts almost instantaneously with ammonia to form NH4Cl. Therefore, there is a high probability that the composition of the human breath medium is transformed after it is formed in the human body and before it is released in the atmosphere. It should also be noted that the new compounds

Magnetic-field-assisted synthesis of anisotropic iron oxide particles: Effect of pH

• Andrey V. Shibaev,
• Petr V. Shvets,
• Darya E. Kessel,
• Roman A. Kamyshinsky,
• Anton S. Orekhov,
• Sergey S. Abramchuk,
• Alexei R. Khokhlov and
• Olga E. Philippova

Beilstein J. Nanotechnol. 2020, 11, 1230–1241, doi:10.3762/bjnano.11.107

• assays using different molar ratios (R) of ammonia (OH− ion source) and iron ions. The authors showed that Fe3O4 particles were not produced by a direct reaction of Fe3+, Fe2+, and OH− ions, but rather via formation of several iron oxyhydroxides (including goetite or lepidocrocite) and their further

Gas-sensing features of nanostructured tellurium thin films

• Dumitru Tsiulyanu

Beilstein J. Nanotechnol. 2020, 11, 1010–1018, doi:10.3762/bjnano.11.85

• microcrystalline Te films have remarkable, sensitive properties toward ammonia [8][9] and hydrogen sulfide [10] and, to a lesser extent, to carbon oxides and amines [11]. In the last years, due to the increase in the general interest toward nanodimensional devices and structures, significant attention has been

• NO2, H2S or ammonia. This is the main reason why this method was used in this work to manufacture and examine Te films. According to the SEM image shown in Figure 1A, nanocrystalline Te films grown on glass substrates present a uniform and dense distribution of randomly oriented nanocrystalline grains

Wet-spinning of magneto-responsive helical chitosan microfibers

• Dorothea Brüggemann,
• Johanna Michel,
• Naiana Suter,
• Matheus Grande de Aguiar and
• Michael Maas

Beilstein J. Nanotechnol. 2020, 11, 991–999, doi:10.3762/bjnano.11.83

• 4 to 12 MPa were previously obtained for wet-spinning of bare chitosan solutions into ammonia [35]. These results were in good agreement with the Young’s modulus values obtained for our helical chitosan fibers. On the other hand, gel-spinning in combination with a post-drying step led to much higher

Preparation, characterization and photocatalytic performance of heterostructured CuO–ZnO-loaded composite nanofiber membranes

• Wei Fang,
• Liang Yu and
• Lan Xu

Beilstein J. Nanotechnol. 2020, 11, 631–650, doi:10.3762/bjnano.11.50

• chloride (ZnCl2, Mw = 73.09 g/mol), hexamethylenetetramine (C6H12N4, Mw = 140.19 g/mol) and ammonia (NH3·H2O, Mw = 17.03 g/mol) were supplied from China Pharmaceutical Group Chemical Reagents Co., Ltd. (Shanghai, China). Methyl orange (Mw = 327.34 g/mol) was purchased from Shanghai Debai Biotechnology Co

Identification of physicochemical properties that modulate nanoparticle aggregation in blood

• Ludovica Soddu,
• Duong N. Trinh,
• Eimear Dunne,
• Dermot Kenny,
• Giorgia Bernardini,
• Ida Kokalari,
• Arianna Marucco,
• Marco P. Monopoli and
• Ivana Fenoglio

Beilstein J. Nanotechnol. 2020, 11, 550–567, doi:10.3762/bjnano.11.44

• ) for the medium and small carbon nanoparticles (CNP-M and CNP-S, respectively). Synthesis of silica nanoparticles Silica nanoparticles (SNPs) were prepared by hydrolysis and condensation of TEOS in the presence of ammonia as a catalyst following the Stöber process [25]. Briefly, a defined amount of

• TEOS was added to a solution containing ethanol, ammonia (33%) and ultrapure water under magnetic stirring and at room temperature for 30–40 min. The ratio of the reagents was modified in order to control the NPs size (Table 2). The NP suspension was centrifuged at 11,000 rcf for 15 min and the

Facile biogenic fabrication of hydroxyapatite nanorods using cuttlefish bone and their bactericidal and biocompatibility study

• Satheeshkumar Balu,
• Manisha Vidyavathy Sundaradoss,
• Swetha Andra and
• Jaison Jeevanandam

Beilstein J. Nanotechnol. 2020, 11, 285–295, doi:10.3762/bjnano.11.21

• Hap NRs will be highly useful in the fabrication of novel implants for orthopedic and dental applications. Materials and Methods The experiments were performed in a 1000 mL round bottom flask filled with calcium carbonate (CB powder), (NH4)2HPO4 and ammonia solution. The oil bath setup was used to

• adjusted from 8 to 12 using ammonia solution. This mixture was allowed to stir for various reaction times of 6, 12, 24, and 48 h at 80 °C and then the final precipitate was washed with distilled water and ethanol to remove impurities. Finally, the precipitate was dried at 60 °C in a hot air oven and was

Synthesis of amorphous and graphitized porous nitrogen-doped carbon spheres as oxygen reduction reaction catalysts

• Maximilian Wassner,
• Markus Eckardt,
• Andreas Reyer,
• Thomas Diemant,
• Michael S. Elsaesser,
• R. Jürgen Behm and
• Nicola Hüsing

Beilstein J. Nanotechnol. 2020, 11, 1–15, doi:10.3762/bjnano.11.1

• synthesized by hydrothermal treatment of a glucose solution yielding carbon spheres with sizes of 330 ± 50 nm, followed by nitrogen doping via heat treatment in ammonia atmosphere. The influence of a) varying the nitrogen doping temperature (550–1000 °C) and b) of a catalytic graphitization prior to nitrogen

• are chemical vapor deposition (CVD) and arc discharge methods for N-doped graphene, graphite, and carbon nanotubes [9]. Most commonly, the post-synthetic approach is carried out by thermal treatment of carbon in ammonia atmosphere, typically leading to surface N-doping. A variety of N bonding

• . Annealing graphene oxide (GO) in an ammonia atmosphere at 550 °C led to pyridinic N-doped graphene, while at a temperature of 850 °C graphitic nitrogen coexisted with pyridinic nitrogen, and for higher temperatures the amount of graphitic N increased. Annealing GO at 850 °C in the presence of polyaniline or

pH-Controlled fluorescence switching in water-dispersed polymer brushes grafted to modified boron nitride nanotubes for cellular imaging

• Saban Kalay,
• Yurij Stetsyshyn,
• Volodymyr Donchak,
• Khrystyna Harhay,
• Ostap Lishchynskyi,
• Halyna Ohar,
• Yuriy Panchenko,
• Stanislav Voronov and
• Mustafa Çulha

Beilstein J. Nanotechnol. 2019, 10, 2428–2439, doi:10.3762/bjnano.10.233

• under acidic conditions [42]. In our previous work [12], we have reported a two-step method for preparation of a responsive surface layer on oligoperoxide-functionalized BNNTs, where amino groups on BNNTs form at the ends and defects. Additional amine groups can be easily introduced with ammonia plasma

• -dependent fluorescence properties. Third, acrylic groups in P(AA-co-FA) can be easy modified for drugs and/or targeting agents similar to that reported in [61]. It is well known that the carboxyl group of acrylic acid can react with ammonia to form acrylamide, or with an alcohol to form an acrylate ester

Coating of upconversion nanoparticles with silica nanoshells of 5–250 nm thickness

• Cynthia Kembuan,
• Maysoon Saleh,
• Bastian Rühle,
• Ute Resch-Genger and
• Christina Graf

Beilstein J. Nanotechnol. 2019, 10, 2410–2421, doi:10.3762/bjnano.10.231

• followed by a stepwise growth of these particles without a purification step, where in each step equal volumes of tetraethyl orthosilicate and ammonia water are added, while the volumes of cyclohexane and the surfactant Igepal® CO-520 are increased so that the ammonia water and surfactant concentrations

• microemulsion method. The Stöber method refers to the process of preparing silica via the hydrolysis and condensation of tetraethyl orthosilicate (TEOS) within an alcohol–ammonia–water system [25]. Related methods are widely used for coating NPs that are dispersible in polar media [26][27]. Modified Stöber

• name Igepal® CO-520) and distributed in the continuous nonpolar phase [44]. The ratio between the aqueous components and the surfactant determines the size of these droplets [30], which act as nanoreactors. For the polycondensation of precursors such as TEOS, ammonia usually acts as a catalyst [43

Synthesis of highly active ETS-10-based titanosilicate for heterogeneously catalyzed transesterification of triglycerides

• Muhammad A. Zaheer,
• David Poppitz,
• Khavar Feyzullayeva,
• Marianne Wenzel,
• Jörg Matysik,
• Radomir Ljupkovic,
• Aleksandra Zarubica,
• Alexander A. Karavaev,
• Andreas Pöppl,
• Roger Gläser and
• Muslim Dvoyashkin

Beilstein J. Nanotechnol. 2019, 10, 2039–2061, doi:10.3762/bjnano.10.200

The influence of porosity on nanoparticle formation in hierarchical aluminophosphates

• Matthew E. Potter,
• Lauren N. Riley,
• Alice E. Oakley,
• Panashe M. Mhembere,
• June Callison and
• Robert Raja

Beilstein J. Nanotechnol. 2019, 10, 1952–1957, doi:10.3762/bjnano.10.191

• porosity. Specifically, we compare three known methods for nanoparticle preparation, incipient wetness (IW), wet impregnation (WI) and ammonia evaporation (AE), on the typical microporous (MP-SAPO-5) and corresponding hierarchically porous system (HP-SAPO-5) [15][16]. MP-SAPO-5 was synthesised according to

Upcycling of polyurethane waste by mechanochemistry: synthesis of N-doped porous carbon materials for supercapacitor applications

• Christina Schneidermann,
• Pascal Otto,
• Desirée Leistenschneider,
• Sven Grätz,
• Claudia Eßbach and
• Lars Borchardt

Beilstein J. Nanotechnol. 2019, 10, 1618–1627, doi:10.3762/bjnano.10.157

• to 670 m2·g−1 and to 0.27 cm3·g−1, while the nitrogen content increases to 6.3 wt % (Table 1). This observation is related to an intensified chemical activation process due to the high amount of urea and the formation of ammonia during the high-temperature treatment, leading to a higher consumption

• of carbon and its partial textural destruction. In addition to the formation of ammonia and the activation of the carbon, urea can form (NH4)2(CO3), which further decomposes to gaseous H2O, CO2 and NH3 and leads to additional porosity of the carbon. In order to attenuate the activation process, while

High-temperature resistive gas sensors based on ZnO/SiC nanocomposites

• Vadim B. Platonov,
• Marina N. Rumyantseva,
• Alexander S. Frolov,
• Alexey D. Yapryntsev and
• Alexander M. Gaskov

Beilstein J. Nanotechnol. 2019, 10, 1537–1547, doi:10.3762/bjnano.10.151

• semiconductor materials: where CO(gas), NH3(gas) are molecules of carbon monoxide and ammonia in the gas phase, is a particle of chemisorbed oxygen, e− is an electron released into the conduction band; CO2(gas), N2(gas), H2O(gas) are the molecules of the reaction products desorbed from the surface of the

Selective gas detection using Mn₃O₄/WO₃ composites as a sensing layer

• Yongjiao Sun,
• Zhichao Yu,
• Wenda Wang,
• Pengwei Li,
• Gang Li,
• Wendong Zhang,
• Lin Chen,
• Serge Zhuivkov and
• Jie Hu

Beilstein J. Nanotechnol. 2019, 10, 1423–1433, doi:10.3762/bjnano.10.140

• between the two metal oxides. The sensor based on the Mn3O4/WO3 composite with 3 atom % Mn showed a high selective response to hydrogen sulfide (H2S), ammonia (NH3) and carbon monoxide (CO) at working temperatures of 90 °C, 150 °C and 210 °C, respectively. The demonstrated superior selectivity opens the

• surface oxygen species and conduction band, finally resulting in a higher response. However, an excess amount of Mn3O4 has a negative influence on the response of the gas sensor because of the decrease of the effective reaction areas between WO3 and ammonia molecules [36]. Ultimately, we found that the 3

• atom % Mn3O4/WO3 composites have the best ammonia sensing performance. Conclusion In summary, WO3 and Mn3O4/WO3 composites with different concentrations of Mn were prepared and characterized. Their selective gas sensing properties were investigated, and the measurement results show that the gas sensors

Gas sensing properties of individual SnO₂ nanowires and SnO₂ sol–gel nanocomposites

• Alexey V. Shaposhnik,
• Dmitry A. Shaposhnik,
• Sergey Yu. Turishchev,
• Olga A. Chuvenkova,
• Stanislav V. Ryabtsev,
• Alexey A. Vasiliev,
• Xavier Vilanova,
• Francisco Hernandez-Ramirez and
• Joan R. Morante

Beilstein J. Nanotechnol. 2019, 10, 1380–1390, doi:10.3762/bjnano.10.136

• sensor response due to the unlikelihood of sample recrystallization. The results from the ammonia detection experiments showed that the ratio of the sensor response to the surface area exhibits similar values for both the individual nanowire and nanopowders-based sensor materials. Keywords: gas sensors

• Virgili (Tarragona, Spain). The preliminary results concerning this publication were discussed at Eurosensors conferences [32][33]. The present work presents a comparative study of the material properties of SnO2 devices prepared by different methods and by using ammonia as a reference gas for the

• assessment of their sensing characteristics. The use of ammonia in recent works is due to the strong interest in this gas as a marker for stomach diseases and to our collaboration with a company producing suitable measurement instruments in Russia (St. Petersburg). Experimental Material synthesis and

A silver-nanoparticle/cellulose-nanofiber composite as a highly effective substrate for surface-enhanced Raman spectroscopy

• Yongxin Lu,
• Yan Luo,
• Zehao Lin and
• Jianguo Huang

Beilstein J. Nanotechnol. 2019, 10, 1270–1279, doi:10.3762/bjnano.10.126

• Silver nitrate (AgNO3), β-ᴅ-glucose and concentrated ammonia were bought from Sinopharm Chemical Reagent Co., Ltd. (Shanghai, China); sodium hydrate (NaOH) was purchased from Shanghai Titanchem Co., Ltd. (Shanghai, China); Rhodamine 6G (R6G, 98.5%) was obtained from J&K Chemical Ltd. (Shanghai, China

Green fabrication of lanthanide-doped hydroxide-based phosphors: Y(OH)₃:Eu³⁺ nanoparticles for white light generation

• Tugrul Guner,
• Anilcan Kus,
• Mehmet Ozcan,
• Aziz Genc,
• Hasan Sahin and
• Mustafa M. Demir

Beilstein J. Nanotechnol. 2019, 10, 1200–1210, doi:10.3762/bjnano.10.119

• degrades into ammonia that acts as hydroxide source. In this study, HMTA was replaced with LiOH, and Y(OH)3:Eu3+ crystals were obtained through the interaction of OH− ions released from LiOH with Y3+ ions from the yttrium source in water at room temperature. Even at 5 min, Y(OH)3:7.5% Eu3+ crystals were

• process where there is more time to act on these particular crystals. The crystal growth mechanism is summarized and illustrated in Scheme 1. Compared to HMTA, which decomposes into ammonia and releases OH− ions slowly, LiOH is able to give OH− ions through complete dissociation directly to the reaction