Morphology-driven gas sensing by fabricated fractals: A review

• Vishal Kamathe and
• Rupali Nagar

Beilstein J. Nanotechnol. 2021, 12, 1187–1208, doi:10.3762/bjnano.12.88

• , NO2 and SO2 gases at 100 ppm gas at 350 degree centigrade. Though the morphology of the fractals did not change appreciably, Pt doping led to faster response and recovery times. This could be due to the excellent interaction of Pt with hydrogen via the established spillover effect that catalyzes

• hydrogen adsorption [64][65]. Figure 5d depicts the response of fab-fracs with D = 2.43 and 2.49 for different gases. Pt decoration can be seen to improve the sensing performance for all analyte vapors, and this can be attributed to the higher catalytic activity due to Pt 5d electrons and the fractal

• at 250 °C. The study shows that the SnO2/CuO nanoscale hybrid foam sensor outperforms the porous 3D network structure, mainly due to larger surface area, the formation of p–n junctions, and the sulfurization of CuO on metallic conductors. The foam sensor also showed a response to 20 ppm of hydrogen

Self-assembly of amino acids toward functional biomaterials

• Huan Ren,
• Lifang Wu,
• Lina Tan,
• Yanni Bao,
• Yuchen Ma,
• Yong Jin and
• Qianli Zou

Beilstein J. Nanotechnol. 2021, 12, 1140–1150, doi:10.3762/bjnano.12.85

• -ordered structures from a complex mixture via noncovalent interactions, including van der Waals forces, electrostatic forces, hydrogen bonds, and stacking interactions [12][13]. Importantly, biomolecules, such as proteins, peptides, or biologically derived molecules, including de novo designed peptides or

• and molecular forces play a key role in self-assembly, including hydrogen bonds, hydrophobic bonds, van der Waals force, ionic bonds, π–π stacking, and electrostatic forces [31]. Importantly, amino acids are simple building blocks that provide relevant noncovalent interactions to construct complex

• assemblies at the nanoscale. This component exhibits regular aggregate properties through hydrogen bonding and ion interaction, which are highly similar to those of amyloid components, suggesting that it may be associated with the etiology of amyloid-related diseases. Besides, the resulting structure is as

pH-driven enhancement of anti-tubercular drug loading on iron oxide nanoparticles for drug delivery in macrophages

• Karishma Berta Cotta,
• Sarika Mehra and
• Rajdip Bandyopadhyaya

Beilstein J. Nanotechnol. 2021, 12, 1127–1139, doi:10.3762/bjnano.12.84

• absence of NOR or its presence in very minute quantities (Figure 4d). A shift observed in the FTIR peak for OH stretching from 3420 cm−1 to 3440 cm−1 (Supporting Information File 1, Figure S2) could be a result of changes in the intermolecular H bonding, whereby we believe that a fraction of the hydrogen

Progress and innovation of nanostructured sulfur cathodes and metal-free anodes for room-temperature Na–S batteries

• Marina Tabuyo-Martínez,
• Bernd Wicklein and
• Pilar Aranda

Beilstein J. Nanotechnol. 2021, 12, 995–1020, doi:10.3762/bjnano.12.75

A Au/CuNiCoS₄/p-Si photodiode: electrical and morphological characterization

• Adem Koçyiğit,
• Adem Sarılmaz,
• Teoman Öztürk,
• Faruk Ozel and
• Murat Yıldırım

Beilstein J. Nanotechnol. 2021, 12, 984–994, doi:10.3762/bjnano.12.74

• quaternary CuNiCoS4 nanocrystals. The first study by Thompson is on the synthesis of CuNiCoS4 thiospinels [13]. The second is a study on the synthesis and photocatalytic hydrogen evolution, which was performed by our group [8]. In this study, the optical characterization results of the CuNiCoS4 nanocrystals

Uniform arrays of gold nanoelectrodes with tuneable recess depth

• Elena O. Gordeeva,
• Ilya V. Roslyakov,
• Alexey P. Leontiev,
• Alexey A. Klimenko and
• Kirill S. Napolskii

Beilstein J. Nanotechnol. 2021, 12, 957–964, doi:10.3762/bjnano.12.72

• hydrogen evolution manifests itself by the decrease in the current efficiency (η). It ranged from 98% to 100% for Ed values from −0.1 to −0.3 V, whereas, the η value at Ed = −0.4 V decreased below 97% (Table 1). The electrodeposition at potentials above −0.1 V leads to a significant decrease in the Cu

Molecular assemblies on surfaces: towards physical and electronic decoupling of organic molecules

• Sabine Maier and
• Meike Stöhr

Beilstein J. Nanotechnol. 2021, 12, 950–956, doi:10.3762/bjnano.12.71

• molecules from a semiconducting substrate is discussed for the example of both insulating CaF2 thin films on Si(111) [91] and hydrogen passivation of Ge(001) surfaces [92]. In the first case, three scenarios were compared: PTCDA on Si, on a thin CaF2, and on a thicker CaF2 layer. While isolated PTCDA

The role of deep eutectic solvents and carrageenan in synthesizing biocompatible anisotropic metal nanoparticles

• Nabojit Das,
• Akash Kumar and
• Raja Gopal Rayavarapu

Beilstein J. Nanotechnol. 2021, 12, 924–938, doi:10.3762/bjnano.12.69

• oxide nanoparticles [28]. Numerous indispensable parameters including surface tension, polarity, viscosity, and hydrogen bonding have an important influence on the reactivity of species. Also, the formation of nanostructures is governed by the mass transport properties of the DES components. It is also

• possible to modulate the viscosity of DESs, especially NADES, by varying the composition ratio of hydrogen bond donor and hydrogen bond acceptor components [29]. Also, the growth mechanisms and nucleation processes of nanoparticles are highly modulated by the components of DESs through modifying reduction

• melting points, which interact via hydrogen bond to form a fluid at room temperature with a freezing temperature much below that of the individual precursor components. These strong hydrogen bonds restrict the recrystallization of the parent compounds [72]. There are numerous reports on DESs from various

Modification of a SERS-active Ag surface to promote adsorption of charged analytes: effect of Cu²⁺ ions

• Bahdan V. Ranishenka,
• Andrei Yu. Panarin,
• Irina A. Chelnokova,
• Sergei N. Terekhov,
• Peter Mojzes and
• Vadim V. Shmanai

Beilstein J. Nanotechnol. 2021, 12, 902–912, doi:10.3762/bjnano.12.67

• remaining polymer molecules are not able to generate a strong positive charge at the surface but they improve the adsorption of the analyte molecules due to hydrogen bonding and donor–acceptor and lipophilic interactions. SERS analysis of dye-labeled oligonucleotides Biomolecules such as nucleotides and

• ]. The same modification protocol was applied as for glass and the silicon supports. The substrates were treated with a 1:1 (by mass) mixture of concentrated H2SO4 and 30% hydrogen peroxide water solution for 2 h, rinsed with distilled water, and dried. The cleaned substrates were treated with a solution

The role of convolutional neural networks in scanning probe microscopy: a review

• Ido Azuri,
• Irit Rosenhek-Goldian,
• Neta Regev-Rudzki,
• Georg Fantner and
• Sidney R. Cohen

Beilstein J. Nanotechnol. 2021, 12, 878–901, doi:10.3762/bjnano.12.66

Comprehensive review on ultrasound-responsive theranostic nanomaterials: mechanisms, structures and medical applications

• Sepand Tehrani Fateh,
• Lida Moradi,
• Elmira Kohan,
• Michael R. Hamblin and
• Amin Shiralizadeh Dezfuli

Beilstein J. Nanotechnol. 2021, 12, 808–862, doi:10.3762/bjnano.12.64

• concentration supports this conclusion [202]. Dong and colleagues prepared plasma MBs by mixing plasma gas and surfactant using an emulsification process. These MBs released the loaded drug and also generated active free radicals (including nitric oxide and hydrogen peroxide) in response to US irradiation [205

Recent progress in magnetic applications for micro- and nanorobots

• Ke Xu,
• Shuang Xu and
• Fanan Wei

Beilstein J. Nanotechnol. 2021, 12, 744–755, doi:10.3762/bjnano.12.58

• enabled actuation, control, and observation of the FMSM. In most mobile sensing applications, microrobots are driven by chemical fuels such as hydrogen peroxide (H2O2) and surfactants. In contrast, magnetic drives have good biocompatibility and external power supply. For example, a porous microelectrode

Prediction of Co and Ru nanocluster morphology on 2D MoS₂ from interaction energies

• Cara-Lena Nies and
• Michael Nolan

Beilstein J. Nanotechnol. 2021, 12, 704–724, doi:10.3762/bjnano.12.56

• MoS2 ML, where n = 1–4. Co and Ru are of great interest in conjunction with MoS2 for application in advanced interconnects as alternatives to Cu [30][31][32][33][34][35] and TaN. Applications in catalysis include Pt-free hydrogen evolution catalysts [36][37][38][39][40][41]. Interconnects require high

Nanogenerator-based self-powered sensors for data collection

• Yicheng Shao,
• Maoliang Shen,
• Yuankai Zhou,
• Xin Cui,
• Lijie Li and
• Yan Zhang

Beilstein J. Nanotechnol. 2021, 12, 680–693, doi:10.3762/bjnano.12.54

• under exposure to oxygen (O2), hydrogen sulfide (H2S) gas, and water vapor. The sensitivity to H2S gas was as low as 100 ppm. The design of the whole self-powered sensor system consists of three parts. A ZnO NW array as the piezoelectric energy generation module, Ti foil and Al layer as electrodes, and

A review of defect engineering, ion implantation, and nanofabrication using the helium ion microscope

• Frances I. Allen

Beilstein J. Nanotechnol. 2021, 12, 633–664, doi:10.3762/bjnano.12.52

• irradiation in the HIM, this time using a defocused beam to irradiate larger areas, has also been used to generate defects in exfoliated flakes of molybdenum dichalcogenides (MoS2 and MoSe2) to activate the catalytic activity of the basal planes of the crystal for hydrogen evolution reactions [69]. Thermal

Nanoporous and nonporous conjugated donor–acceptor polymer semiconductors for photocatalytic hydrogen production

• Zhao-Qi Sheng,
• Yu-Qin Xing,
• Yan Chen,
• Guang Zhang,
• Shi-Yong Liu and
• Long Chen

Beilstein J. Nanotechnol. 2021, 12, 607–623, doi:10.3762/bjnano.12.50

• tunable bandgaps, high charge carrier mobility, and efficient intramolecular charge transfer. In this minireview, recent advances of D–A polymers in photocatalytic hydrogen evolution are summarized with a particular focus on modulating the optical and electronic properties of CPs by varying the acceptor

• units. The challenges and prospects associated with D–A polymer-based photocatalysts are described as well. Keywords: π-conjugated polymeric photocatalysts; donor–acceptor junctions; nanostructure semiconductors; photocatalytic hydrogen production; Introduction To date, fossil fuels still are the

• , fossil fuels are limited and will be depleted. Regarding clean and sustainable energy resources, in particular solar energy has become a candidate to eventually replace fossil fuels. Among the various strategies, hydrogen production by photocatalytic water splitting is emerging as a promising approach

Stability and activity of platinum nanoparticles in the oxygen electroreduction reaction: is size or uniformity of primary importance?

• Kirill O. Paperzh,
• Anastasia A. Alekseenko,
• Vadim A. Volochaev,
• Ilya V. Pankov,
• Olga A. Safronenko and
• Vladimir E. Guterman

Beilstein J. Nanotechnol. 2021, 12, 593–606, doi:10.3762/bjnano.12.49

• hydrogen oxidation or an organic reducing agent oxidation (e.g. methanol) occur [4][5]. The need to carry out high-rate electrode reactions requires electrocatalysts (i.e., platinum nanoparticles – NPs – or its alloys), deposited mainly onto nano/microparticles of carbon supports, which are currently the

• ) (Pine Research Instruments, USA). A saturated silver chloride electrode was used as a reference electrode. The potentials were given with regard to a reversible hydrogen electrode (RHE). A thin, porous catalyst layer was applied to the electrode using the so-called "catalytic ink". To obtain a

• for desorption (Qd) and adsorption (Qad) of atomic hydrogen, as described in more detail in Supporting Information File 1. The CV recording rate was 20 mV·s−1 and the potential range was 0.04–1.2 V relative to RHE. To determine the ORR activity of the catalysts, the electrolyte was saturated with

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

• aqueous solutions are used with the addition of an oxidizer – usually hydrogen peroxide (H2O2). Such an etchant is able to turn GaAs into oxide and dissolve the created oxides “at the same time”. The popular etchants are H2SO4/H2O2/H2O, NH4OH/H2O2/H2O, and citric acid (CA)-based etchants – CA/H2O2/H2O [17

• minutes raised it to room temperature (RT). Just before the etching process, the dissolved CA in DIW was mixed (1:1, v:v) with hydrogen peroxide (30%). The solution temperature was set to 24 °C and kept at this value during the etching process for 2 min in a USC. The etching rate of such a solution, with

Properties of graphene deposited on GaN nanowires: influence of nanowire roughness, self-induced nanogating and defects

• Jakub Kierdaszuk,
• Piotr Kaźmierczak,
• Justyna Grzonka,
• Aleksandra Krajewska,
• Aleksandra Przewłoka,
• Wawrzyniec Kaszub,
• Zbigniew R. Zytkiewicz,
• Marta Sobanska,
• Maria Kamińska,
• Andrzej Wysmołek and
• Aneta Drabińska

Beilstein J. Nanotechnol. 2021, 12, 566–577, doi:10.3762/bjnano.12.47

• and hydrogen dopants in the pyridinic position result in n-type doping [48]. Thus, defect origin and density impact graphene strain and carrier concentration as well as the interaction with the substrate. The G band is generated by the scattering on iTO or iLO phonons near the Γ point of the Brillouin

The preparation temperature influences the physicochemical nature and activity of nanoceria

• Robert A. Yokel,
• Wendel Wohlleben,
• Johannes Georg Keller,
• Matthew L. Hancock,
• Jason M. Unrine,
• D. Allan Butterfield and
• Eric A. Grulke

Beilstein J. Nanotechnol. 2021, 12, 525–540, doi:10.3762/bjnano.12.43

• +, consistent with the interpretation that nanoceria dissolution occurs at the solid–liquid interface [14]. Cerium ions may then complex with phosphate. Nanoceria dissolution is pH-dependent ([14][39][70] and Figure 11). Nanoceria dissolution presumably results from an interaction between the hydrogen ion and

• the nanoceria surface. A hypothesis is that hydrogen “steals” oxygen from the Ce3+ of the surface Ce–O complex, enabling Ce3+ release. This would be consistent with increased dissolution as the pH value decreases, surface Ce3+ increases, and size decreases (and surface Ce3+ increases). Also, there is

Surface-enhanced Raman scattering of water in aqueous dispersions of silver nanoparticles

• Paulina Filipczak,
• Krzysztof Hałagan,
• Jacek Ulański and
• Marcin Kozanecki

Beilstein J. Nanotechnol. 2021, 12, 497–506, doi:10.3762/bjnano.12.40

• of water molecules) and models of water as a mixture of discrete species (water clusters) [5][6][7][8]. It is difficult to choose between them because the spatial network of hydrogen bonds has features of both continuous and discrete models. The broad Raman band of water located in the range of 3000

• usually assigned to strongly hydrogen-bonded water molecules, or the so-called locally structured water, while the band at 3400 cm−1 is attributed to loosely bonded water molecules. Most of the authors distinguish three [15][16] or four [13] components of the band in the OH stretching vibration region

• . Irrespective of how the spectra are deconvoluted, all models of liquid water agree that the lower the frequency of the band, the stronger the hydrogen bonds and water structuration. The interactions with various solutes [17][18] and the influence of the temperature [13] on the water structure can be analysed

Boosting of photocatalytic hydrogen evolution via chlorine doping of polymeric carbon nitride

• Malgorzata Aleksandrzak,
• Michalina Kijaczko,
• Wojciech Kukulka,
• Daria Baranowska,
• Martyna Baca,
• Beata Zielinska and
• Ewa Mijowska

Beilstein J. Nanotechnol. 2021, 12, 473–484, doi:10.3762/bjnano.12.38

• the hydrogen evolution reaction. The following aspects were found to enhance the photocatalytic efficiency of Cl-PCN: (i) unique location of Cl atoms at the interlayers of PCN instead of on its π-conjugated planes, (ii) slight bandgap narrowing, (iii) lower recombination rate of the electron–hole

• pairs, (iv) improved photogenerated charge transport and separation, and (v) higher reducing ability of the photogenerated electrons. The above factors affected the 4.4-fold enhancement of the photocatalytic efficiency in hydrogen evolution in comparison to the pristine catalyst. Keywords: chlorine

• ; doping; hydrogen evolution reaction; photocatalysis; polymeric carbon nitride; Introduction Currently, the biggest problems of civilization seem to be the global energy crisis and environmental pollution. Both of these problems are directly related to each other. The pollution of our planet is mainly

A review on nanostructured silver as a basic ingredient in medicine: physicochemical parameters and characterization

• Gabriel M. Misirli,
• Kishore Sridharan and
• Shirley M. P. Abrantes

Beilstein J. Nanotechnol. 2021, 12, 440–461, doi:10.3762/bjnano.12.36

• from the damaged respiratory chain since they depend on thiol groups which are occupied by silver ions. The increase in superoxide and hydrogen peroxide anions in the reaction with iron (Fenton reaction), according to Equation 2 [104] and as described in Figure 6, are indicative of the deleterious

Nickel nanoparticle-decorated reduced graphene oxide/WO₃ nanocomposite – a promising candidate for gas sensing

• Ilka Simon,
• Alexandr Savitsky,
• Rolf Mülhaupt,
• Vladimir Pankov and
• Christoph Janiak

Beilstein J. Nanotechnol. 2021, 12, 343–353, doi:10.3762/bjnano.12.28

• nanoparticles loaded with graphene have an enhanced acetone response at 350 °C with increased graphene loading level (best at 5 wt % graphene) [40]. ZnO nanostructures doped with nickel and rGO were used for hydrogen sensing at 100 °C [34]. The decoration of MOS with a noble metal, such as Pd or Pt, improves

• the sensitivity, response time and working temperature of MOS/rGO systems [15][41]. TiO2/rGO decorated with Pd and Pt nanoparticles was successfully used in the gas sensing of hydrogen gas [19]. The decoration of WO3/rGO nanosheets with Pt nanoparticles yielded a faster response for acetone at 200 °C

Doxorubicin-loaded gold nanorods: a multifunctional chemo-photothermal nanoplatform for cancer management

• Uzma Azeem Awan,
• Abida Raza,
• Shaukat Ali,
• Rida Fatima Saeed and
• Nosheen Akhtar

Beilstein J. Nanotechnol. 2021, 12, 295–303, doi:10.3762/bjnano.12.24

• -related side effects in cancer management. Experimental Materials CTAB (99.9%), hydrogen tetrachloroaurate(III) trihydrate (HAuCl4·3H2O 99%), ʟ-ascorbic acid (C6H8O6, 99%), sodium borohydride (NaBH4, 98%), silver nitrate (AgNO3, 99%), doxorubicin, (98%) poly(sodium 4-styrenesulfonate) (PSS; Mw = 70,000