Multilayer capsules made of weak polyelectrolytes: a review on the preparation, functionalization and applications in drug delivery

• Varsha Sharma and
• Anandhakumar Sundaramurthy

Beilstein J. Nanotechnol. 2020, 11, 508–532, doi:10.3762/bjnano.11.41

• CNTs ruptured upon laser light irradiation [115]. The introduction of graphene oxide (GO) nanosheets with PDDA as multilayers caused the migration and rearrangement of chains compared to PDDA/PAA multilayers [116]. The PDDA/GO multilayers showed improved resistance to damage and maintained a defect

Electrochemically derived functionalized graphene for bulk production of hydrogen peroxide

• Munaiah Yeddala,
• Pallavi Thakur,
• Anugraha A and
• Tharangattu N. Narayanan

Beilstein J. Nanotechnol. 2020, 11, 432–442, doi:10.3762/bjnano.11.34

• (Se) edge functionalized graphene (reduced graphene oxide (rGO)) was found to undergo a direct four-electron path ORR process in alkaline medium, where rGO undergoes a two-electron path peroxide route ORR [35]. In this process, Se acts as a single atom site catalyst. In a nutshell, depending on the

• charge transfer properties of functionalized graphene (graphene oxide (GO) or other functional derivatives of graphene) [41]. Hence the single-step method for the production of large scale, controllably functionalized graphene is of high demand, and in this work, we demonstrate such a method to control

Simple synthesis of nanosheets of rGO and nitrogenated rGO

• Pallellappa Chithaiah,
• Madhan Mohan Raju,
• Giridhar U. Kulkarni and
• C. N. R. Rao

Beilstein J. Nanotechnol. 2020, 11, 68–75, doi:10.3762/bjnano.11.7

• , 560064, India 10.3762/bjnano.11.7 Abstract A green and facile approach has been developed for the large-scale synthesis of nanosheets of reduced graphene oxide (rGO) and nitrogenated reduced graphene oxide (N-rGO). This has been achieved by direct thermal decomposition of sucrose and glycine at 475 °C

• hydrogen treated (H-rGO) samples. Keywords: nanosheets; nitrogenated reduced graphene oxide (N-rGO); reduced graphene oxide (rGO); supercapacitors; thermal decomposition; Introduction Graphene, the one atom thick two-dimensional material of sp2-hybridized carbon atoms has attracted much attention after

• its discovery [1][2]. It is a fascinating material used in various applications owing to its excellent electrical, optical, mechanical and thermal properties [3][4][5]. It has a unique electronic structure with a linear dispersion of Dirac electrons. Graphene oxide (GO) and reduced graphene oxide (rGO

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

• . 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

Advanced hybrid nanomaterials

• Andreas Taubert,
• Fabrice Leroux,
• Pierre Rabu and
• Verónica de Zea Bermudez

Beilstein J. Nanotechnol. 2019, 10, 2563–2567, doi:10.3762/bjnano.10.247

• ]. The mesostructures are highly pH-sensitive, adopting 2D-hexagonal, wormlike or lamellar organization depending on the extent of the electrostatic complexing bonds and on the condensation rate. More complex assemblies involving ternary compositions in “Ternary nanocomposites of reduced graphene oxide

Synthesis and acetone sensing properties of ZnFe₂O₄/rGO gas sensors

• Kaidi Wu,
• Yifan Luo,
• Ying Li and
• Chao Zhang

Beilstein J. Nanotechnol. 2019, 10, 2516–2526, doi:10.3762/bjnano.10.242

• of ZnFe2O4 and reduced graphene oxide (rGO) with different rGO content were prepared via a simple solvothermal method followed by a high-temperature annealing process in an inert atmosphere. The X-ray diffraction analysis confirmed that the introduction of rGO had no effect on the spinel structure of

• ; composites; gas sensor; reduced graphene oxide (rGO); ZnFe2O4 hollow spheres; Introduction As a synthetic raw material in industrial production, acetone is chemically active and extremely flammable. It is toxic if its concentration exceeds 173 ppm, and long-term exposure to acetone poses a serious threat to

• ][25][26][27][28]. An optimum ratio of the composition and the fine nanostructure will contribute to obtaining better gas-sensing properties. A gas sensor with 3 wt % reduced graphene oxide (rGO) incorporated into In2O3 showed a rapid response, an improved stability and a low limit of detection of NO2

Multiwalled carbon nanotube based aromatic volatile organic compound sensor: sensitivity enhancement through 1-hexadecanethiol functionalisation

• Nadra Bohli,
• Meryem Belkilani,
• Juan Casanova-Chafer,
• Eduard Llobet and
• Adnane Abdelghani

Beilstein J. Nanotechnol. 2019, 10, 2364–2373, doi:10.3762/bjnano.10.227

• ., single-wall carbon nanotube (SWCNT), multiwall carbon nanotube (MWCNT), graphene, graphene oxide (GO)) present a sensitive active layer exhibiting an electrical resistance change while in contact with the target gas due to interactions at the molecular level [7][8]. These interactions, depending whether

Design and facile synthesis of defect-rich C-MoS₂/rGO nanosheets for enhanced lithium–sulfur battery performance

• Chengxiang Tian,
• Juwei Wu,
• Zheng Ma,
• Bo Li,
• Pengcheng Li,
• Xiaotao Zu and
• Xia Xiang

Beilstein J. Nanotechnol. 2019, 10, 2251–2260, doi:10.3762/bjnano.10.217

• composite with both large surface area and high porosity for the use as advanced electrode material in lithium–sulfur batteries. Double modified defect-rich MoS2 nanosheets are successfully prepared by introducing reduced graphene oxide (rGO) and amorphous carbon. The conductibility of the cathodes can be

• construction of other high-performance metal disulfide electrodes for electrochemical energy storage. Keywords: annealing; double modification; high-performance electrodes; lithium–sulfur battery; molybdenum disulfide (MoS2); reduced graphene oxide (rGO); Introduction Lithium–sulfur (Li–S) batteries have

Ultrathin Ni_1−xCo_xS₂ nanoflakes as high energy density electrode materials for asymmetric supercapacitors

• Xiaoxiang Wang,
• Teng Wang,
• Rusen Zhou,
• Lijuan Fan,
• Shengli Zhang,
• Feng Yu,
• Tuquabo Tesfamichael,
• Liwei Su and
• Hongxia Wang

Beilstein J. Nanotechnol. 2019, 10, 2207–2216, doi:10.3762/bjnano.10.213

• graphene, graphene oxide (GO) or carbon nanotubes (CNTs) in order to improve the charge–discharge process stability [11][12][13]. There are limited reports regarding a comparison of the intrinsic performance between these Ni–Co chalcogenides materials. Even pure Ni–Co chalcogenide nanomaterials have been

TiO₂/GO-coated functional separator to suppress polysulfide migration in lithium–sulfur batteries

• Ning Liu,
• Lu Wang,
• Taizhe Tan,
• Yan Zhao and
• Yongguang Zhang

Beilstein J. Nanotechnol. 2019, 10, 1726–1736, doi:10.3762/bjnano.10.168

• but suffer from poor cyclic performance due to the dissolution of intermediate polysulfides. Herein, a lightweight nanoporous TiO2 and graphene oxide (GO) composite is prepared and utilized as an interlayer between a Li anode and a sulfur cathode to suppress the polysulfide migration and improve the

• effect and the Li/S batteries with these functional interlayers deliver high gravimetric energy density and superior cyclic performance. Two-dimensional graphene oxide (GO) has excellent thermal stability, an ultrahigh specific surface area, and good electrical conductivity. The polysulfide shuttle can

• interlayer enhanced the cycling stability and charge storage capacity of Li/S batteries due to excellent conductivity of graphene oxide and strong chemical interactions between nanoporous TiO2 and polysulfides. Results and Discussion Figure 1 presents a schematic of a Li/S battery with a TiO2/GO-coated

Materials nanoarchitectonics at two-dimensional liquid interfaces

• Katsuhiko Ariga,
• Michio Matsumoto,
• Taizo Mori and
• Lok Kumar Shrestha

Beilstein J. Nanotechnol. 2019, 10, 1559–1587, doi:10.3762/bjnano.10.153

• reported. Jayavel, Shrestha, and co-workers demonstrated the enhanced performance of electrochemical supercapacitors using composites of cobalt oxide nanoparticles and reduced graphene oxide, which are zero-dimensional and two-dimensional nanomaterials, respectively [86]. Leong and co-workers reported a

• applications (by Xu, Lee, and co-workers [135]) and substrate channelling between enzymes with graphene oxide nanosheets (by Yang and co-workers [136]) can be mentioned. The nanoarchitectonics bottom-up approaches preserving the nanostructural properties are highly useful for the fabrication of low-dimensional

Hierarchically structured 3D carbon nanotube electrodes for electrocatalytic applications

• Pei Wang,
• Katarzyna Kulp and
• Michael Bron

Beilstein J. Nanotechnol. 2019, 10, 1475–1487, doi:10.3762/bjnano.10.146

• graphene oxide, etc.) have been recently studied to improve the reaction performance, enhance stability and thus reduce the cost [37][38][39][40][41]. It was reported that Pt supported on these optimized catalyst supports provides higher electrocatalytical activity towards methanol oxidation and increased

Photoactive nanoarchitectures based on clays incorporating TiO₂ and ZnO nanoparticles

• Eduardo Ruiz-Hitzky,
• Pilar Aranda,
• Marwa Akkari,
• Nithima Khaorapapong and
• Makoto Ogawa

Beilstein J. Nanotechnol. 2019, 10, 1140–1156, doi:10.3762/bjnano.10.114

• ), carbonaceous materials (carbon nanotubes, graphene, graphene oxide, and activated carbon), layered double hydroxides, layered polysilicates (magadiite and kenyaite), and metal organic frameworks. The role of the inorganic matrices in the assembly of the semiconductor NPs [55][56][57][58][59] is: i) to control

Direct growth of few-layer graphene on AlN-based resonators for high-sensitivity gravimetric biosensors

• Jimena Olivares,
• Teona Mirea,
• Lorena Gordillo-Dagallier,
• Bruno Marco,
• José Miguel Escolano,
• Marta Clement and
• Enrique Iborra

Beilstein J. Nanotechnol. 2019, 10, 975–984, doi:10.3762/bjnano.10.98

• porous gold films [9], owing to their outstanding properties in terms of electrical conductivity combined with their chemical stability and their ability to alter their chemistry under controlled conditions. Recently, functionalized graphene and graphene oxide have attracted the attention of the

The systemic effect of PEG-nGO-induced oxidative stress in vivo in a rodent model

• Qura Tul Ain,
• Samina Hyder Haq,
• Abeer Alshammari,
• Moudhi Abdullah Al-Mutlaq and
• Muhammad Naeem Anjum

Beilstein J. Nanotechnol. 2019, 10, 901–911, doi:10.3762/bjnano.10.91

• ). Graphene oxide sheets (GOS) were synthesized via a modified Hummer's method and were characterized by X-ray diffraction (XRD), ultraviolet–visible spectroscopy (UV), and transmission electron microscopy (TEM). The method of Zhang was adopted for cracking of GOS. Then nano-graphene oxide was PEGylated with

• increased OS even after 4 h. In conclusion increased OS induced by PEG-nGO could be detrimental to brain, heart and kidneys. Keywords: nano-graphene oxide; nanomedicine; oxidative stress; PEGylation; Introduction The recent progress in nanoscience and nanotechnology that has facilitated the synthesis of

• restricts its use for biomedical applications. Scientists have overcome this challenge through the oxidation of graphene by an improved Hummer’s method [3]. Graphene oxide (GO), due to its hydrophilic nature, can host a large number of biocompatible polymers, such as chitosan [4], polyethylene glycol (PEG

Trapping polysulfide on two-dimensional molybdenum disulfide for Li–S batteries through phase selection with optimized binding

• Sha Dong,
• Xiaoli Sun and
• Zhiguo Wang

Beilstein J. Nanotechnol. 2019, 10, 774–780, doi:10.3762/bjnano.10.77

• Mo by Re atoms [28], electron-beam irradiation [31] and hot-electron injection [32]. Recently, it was reported that MoS2/reduced graphene oxide (rGO)/S cathodes for Li–S batteries exhibit outstanding performance. X-ray photoelectron spectroscopy and Raman spectroscopy showed that few-layered MoS2 is

A porous 3D-RGO@MWCNT hybrid material as Li–S battery cathode

• Yongguang Zhang,
• Jun Ren,
• Yan Zhao,
• Taizhe Tan,
• Fuxing Yin and
• Yichao Wang

Beilstein J. Nanotechnol. 2019, 10, 514–521, doi:10.3762/bjnano.10.52

• , Geelong, Vic 3216, Australia 10.3762/bjnano.10.52 Abstract In this work, a unique three-dimensional (3D) structured carbon-based composite was synthesized. In the composite, multiwalled carbon nanotubes (MWCNT) form a lattice matrix in which porous spherical reduced graphene oxide (RGO) completes the 3D

• cathode. It was believed that a carbon-based material network with specific morphology will not only allow for a high sulfur loading but will also provide both the chemical and physical restraints on the polysulfide shuttle effect. In the previous report, we synthesized porous 3D reduced graphene oxide

• lattice network for the composite that is supported by porous spherical reduced graphene oxide (RGO). Furthermore, the functional groups on RGO provide bonding sites for the active sulfur material. The 3D porous carbon structure enabled high sulfur loading and confined the sulfur within the 3D MWCNT

Reduced graphene oxide supported C₃N₄ nanoflakes and quantum dots as metal-free catalysts for visible light assisted CO₂ reduction

• Md Rakibuddin and
• Haekyoung Kim

Beilstein J. Nanotechnol. 2019, 10, 448–458, doi:10.3762/bjnano.10.44

• , we report the synthesis of novel reduced graphene oxide (rGO)-supported C3N4 nanoflake (NF) and quantum dot (QD) hybrid materials (GCN) for visible light induced reduction of CO2. The C3N4 NFs and QDs are prepared by acid treatment of C3N4 nanosheets followed by ultrasonication and hydrothermal

• conduction band (CB) and valence band (VB) edge positions, exhibit efficient charge separation, have a large surface area, and it must be cost effective. Considering the above factors, nontoxic metal-free catalysts, such as graphitic carbon nitride (g-C3N4) and reduced graphene oxide (rGO) have received wide

• the help of protons. Conclusion Reduced graphene oxide supported C3N4 NF and QD hybrid (GCN) materials have been successfully synthesized via a sol–gel and hydrothermal method and are characterized in this work. The formation of g-C3N4 NFs (20–45 nm) and QDs (2–3 nm) can be controlled by varying the

Scanning probe microscopy for energy-related materials

• Rüdiger Berger,
• Benjamin Grévin,
• Philippe Leclère and
• Yi Zhang

Beilstein J. Nanotechnol. 2019, 10, 132–134, doi:10.3762/bjnano.10.12

• individual graphene oxide sheets” by Yue Shen and co-workers. Yue Shen won the prize for the best presentation during the E-MRS conference [12]. Electrostatic force spectroscopy (EFS) is used here to characterize the degree of reduction of uniformly reduced one-atom-thick graphene oxide (GO) sheets at the

Wet chemistry route for the decoration of carbon nanotubes with iron oxide nanoparticles for gas sensing

• Hussam M. Elnabawy,
• Juan Casanova-Chafer,
• Badawi Anis,
• Mostafa Fedawy,
• Mattia Scardamaglia,
• Carla Bittencourt,
• Ahmed S. G. Khalil,
• Eduard Llobet and
• Xavier Vilanova

Beilstein J. Nanotechnol. 2019, 10, 105–118, doi:10.3762/bjnano.10.10

• composites with other materials such as graphene oxide or polyaniline has been reported to detect NO2 [17][18]. The decoration of CNTs with iron oxide has been reported for sensing different species in air such as acetone, CO2 and some volatile organic compounds [19][20][21]. Moreover, composites made of

Threshold voltage decrease in a thermotropic nematic liquid crystal doped with graphene oxide flakes

• Mateusz Mrukiewicz,
• Krystian Kowiorski,
• Paweł Perkowski,
• Rafał Mazur and
• Małgorzata Djas

Beilstein J. Nanotechnol. 2019, 10, 71–78, doi:10.3762/bjnano.10.7

• /bjnano.10.7 Abstract We report a threshold voltage decrease in a nematic liquid crystal compound, 4-cyano-4′-pentylbiphenyl (5CB), doped with graphene oxide (GO) flakes at a concentration of 0.05–0.3 wt %. The threshold voltage decrease was observed at the same concentration in electro-optic and

• presence of the electric field was discussed. Keywords: graphene oxide; liquid crystal; nematic phase; switching; threshold voltage; Introduction Liquid crystals (LCs) are classified as a type of soft matter which are characterized by anisotropic molecules and a liquid-like fluidity behavior. Of all LC

• elastic constant [19][20][21]. In this work, we discuss our approach in reducing the threshold voltage by using graphene oxide (GO) flakes. The extraordinary properties of GO make this material a good candidate for this purpose. GO is an oxidized form of graphene [22][23][24]. In GO, carbon atoms are

Zn/F-doped tin oxide nanoparticles synthesized by laser pyrolysis: structural and optical properties

• Florian Dumitrache,
• Iuliana P. Morjan,
• Elena Dutu,
• Ion Morjan,
• Claudiu Teodor Fleaca,
• Monica Scarisoreanu,
• Alina Ilie,
• Marius Dumitru,
• Cristian Mihailescu,
• Adriana Smarandache and
• Gabriel Prodan

Beilstein J. Nanotechnol. 2019, 10, 9–21, doi:10.3762/bjnano.10.2

• values. A clear optical behavior influence of the presence of carbon layers on tin dioxide can be observed for the SnO2@C and SnO2@SiO2@C nanostructured microspheres (C symbolizing here reduced graphene oxide, rGO) reported in [53], where the UV–vis spectra show a clear increase in absorbance (mostly in

Co-intercalated layered double hydroxides as thermal and photo-oxidation stabilizers for polypropylene

• Qian Zhang,
• Qiyu Gu,
• Fabrice Leroux,
• Pinggui Tang,
• Dianqing Li and
• Yongjun Feng

Beilstein J. Nanotechnol. 2018, 9, 2980–2988, doi:10.3762/bjnano.9.277

• functional additives have attracted increasing attention for their wide applications in polymers [7]. Organic anti-aging species have been immobilized onto inorganic supports (e.g., carbon nanotubes, SiO2, graphene oxide) to produce inorganic–organic composites with higher migration resistance [8][9][10

Ternary nanocomposites of reduced graphene oxide, polyaniline and hexaniobate: hierarchical architecture and high polaron formation

• Claudio H. B. Silva,
• Maria Iliut,
• Christopher Muryn,
• Christian Berger,
• Zachary Coldrick,
• Vera R. L. Constantino,
• Marcia L. A. Temperini and
• Aravind Vijayaraghavan

Beilstein J. Nanotechnol. 2018, 9, 2936–2946, doi:10.3762/bjnano.9.272

• nanocomposite composed of polyaniline (PANI), reduced graphene oxide (rGO) and hexaniobate (hexNb) nanoscrolls. Atomic force microscopy images show an interesting architecture of rGO flakes coated with PANI and decorated by hexNb. Such features are attributed to the high stability of the rGO flakes prepared at

• morphological aspects. Therefore, the new nanocomposite presents promising properties for development of new materials in the film form on substrates for sensing or corrosion protection for example. Keywords: graphene oxide; hexaniobate; polyaniline; Raman spectroscopy; secondary doping; Introduction

• bipolaronic to polaronic segments compared to the neat polymer and a superior thermal stability (the doped form of PANI is observed even after heating at 150 °C for 90 min). The literature has shown that PANI and reduced graphene oxide (rGO) show enhanced properties when combined at the nanoscale domain and

Graphene-enhanced metal oxide gas sensors at room temperature: a review

• Dongjin Sun,
• Yifan Luo,
• Marc Debliquy and
• Chao Zhang

Beilstein J. Nanotechnol. 2018, 9, 2832–2844, doi:10.3762/bjnano.9.264

• for semiconductor gas sensors [6]. Graphene oxide (GO), as a derivative of graphene, is prepared via the oxidation of graphene. Epoxy groups, hydroxy groups and defects are produced at the surface when oxidizing graphene [7][8][9][10]. These variations will alter the electronic structure of graphene

• -sensing material. Therefore, further reduction of GO is necessary and the product after reduction is called reduced graphene oxide (rGO). Some oxygen functional groups remain after the reduction, some defects and vacancies are generated during the reduction, which are beneficial for the gas adsorption [13

• of semiconductor interfaces Reduced graphene oxide (rGO), which plays the role of a p-type semiconductor, can form heterojunctions when forming composites with most metal-oxide semiconductors. In the example of a SnO2–rGO sensor [45], SnO2 and rGO formed p–n heterojunctions. The enhancement mechanism