Chirality in nanomaterials.

Chirality at the nanoscale has emerged as a key area of interest in materials science and engineering, with significant implications for various fields such as spintronics, photonics, optoelectronics, quantum computing, and biomedicine. With their unique properties such as enantioselective interactions with light and spin-polarized electron transport, chiral nanomaterials are opening a new window of opportunities for the design of advanced functional devices. This editorial provides an overview of the current state of research in chirality in nanomaterials.

Optimization of Magnetic Behaviors of Au-NP-Decorated MWCNTs and Reduced Graphene Oxide for Biomedical Applications.

Optimization of electronic/magnetic behaviors of chemically decorated diamagnetic noble-metal gold nanoparticles (Au-NPs ≈5 at. %) on multiwalled carbon nanotubes (MWCNTs) and reduced graphene oxide (r-GO) is studied for future uses of optoelectronic/magnetic and biomedical applications. The changes between Au 4f and Au 4f ≈ 3.

Possible ferro-electro-magnetic behaviours of graphene-based materials: hydrogenated graphene, MWCNTs and reduced graphene-oxide (GO).

This study investigated the electric polarization and magnetic behaviours of various graphene-based materials, including hydrogenated graphene (H-graphene), multi-wall carbon nanotubes (MWCNTs), and reduced graphene oxide (r-GO). Results showed that MWCNTs exhibit higher magnetization, with a magnetic squareness ( / ) of approximately ≈0.5, compared to H-graphene (≈0.

Bandgap Shrinkage and Charge Transfer in 2D Layered SnS Doped with V for Photocatalytic Efficiency Improvement.

Effects of electronic and atomic structures of V-doped 2D layered SnS are studied using X-ray spectroscopy for the development of photocatalytic/photovoltaic applications. Extended X-ray absorption fine structure measurements at V K-edge reveal the presence of VO and VS bonds which form the intercalation of tetrahedral OVS sites in the van der Waals (vdW) gap of SnS layers. X-ray absorption near-edge structure (XANES) reveals not only valence state of V dopant in SnS is ≈4 but also the charge transfer (CT) from V to ligands, supported by V L resonant inelastic X-ray scattering.

Correlation among photoluminescence and the electronic and atomic structures of SrSiO:xEu phosphors: X-ray absorption and emission studies.

A series of Eu-activated strontium silicate phosphors, SrSiO:xEu (SSO:xEu, x = 1.0, 2.0 and 5.

Engineering of luminescent graphene quantum dot-gold (GQD-Au) hybrid nanoparticles for functional applications.

Graphene quantum dots (GQDs) possess excellent optical and electrical properties that can be used in a wide variety of application. Synthesis of hybrid nanoparticles with GQDs have been known to improve the properties further. Therefore, in this method, graphene quantum dots -gold (GQD-Au) hybrid nanoparticles were synthesized using GQDs which reduces HAuCl3HO to Au nanoparticles on its surface at room temperature.

Zeolitic Imidazolate Framework-8-Encapsulated Nanoparticle of Ag/Cu Composites Supported on Graphene Oxide: Synthesis and Antibacterial Activity.

The rational approach motivated the design of novel antimicrobial silver and silver-copper bimetallic nanoparticles contained within zeolitic imidazolate framework-8 supported on graphene oxide (GO), Ag@ZIF-8@GO, and AgCu@ZIF8@GO. In the resultant composites, ZIF-8 was able to prevent the stacking of GO sheets and also acted as a carrier for the nanoparticles within its cavities. GO, on the other hand, acted as an anchoring support enabling uniform dispersion of the nanocomposites, thus eliminating their aggregation.

All-inorganic quantum dot assisted enhanced charge extraction across the interfaces of bulk organo-halide perovskites for efficient and stable pin-hole free perovskite solar cells.

In spite of achieving high power conversion efficiency (PCE), organo-halide perovskites suffer from long term stability issues. Especially the grain boundaries of polycrystalline perovskite films are considered as giant trapping sites for photo-generated carriers and therefore play an important role in charge transportation dynamics. Surface engineering grain boundary modification is the most promising way to resolve this issue.

Paper based point of care immunosensor for the impedimetric detection of cardiac troponin I biomarker.

Advancements in health care monitoring demand a rapid, accurate and reliable early diagnosis of "Heart Attack" (acute myocardial infarction) with an objective to develop a cost-effective, rapid and label-free point of care diagnostic test kit for the detection of cardiac troponin I (cTnI) on paper-based multi-frequency impedimetric transducers. Paper based sensing platforms were developed by integrating carboxyl group functionalized multi-walled carbon nanotubes (MWCNT) with antibodies of cardiac troponin I (anti-cTnI) biomarker and was characterized using Electrochemical Impedance Spectroscopy (EIS). Various concentrations of cTnI with anti cTnI were studied as a function of impedance change.

Nitridation Temperature Effect on Carbon Vanadium Oxynitrides for a Symmetric Supercapacitor.

In this work, porous carbon-vanadium oxynitride (C-VNO) nanostructures were obtained at different nitridation temperature of 700, 800 and 900 °C using a thermal decomposition process. The X-ray diffraction (XRD) pattern of all the nanomaterials showed a C-VNO single-phase cubic structure. The C-VNO obtained at 700 °C had a low surface area (91.

Electronic, Electrical, and Magnetic Behavioral Change of SiO-NP-Decorated MWCNTs.

Silicon-oxide-nanoparticle (SiO-NP) heteroatoms were decorated/deposited onto multiwall carbon nanotube (MWCNT) surface to tune the properties of MWCNTs for electronic and magnetic applications. To achieve this objective, SiO-NPs and MWCNTs were prepared and suspended together into toluene and heated at <100 °C for the formation of MWCNTs/SiO-NP nanocomposites. A change in the microstructure, electronic, electrical, and magnetic behaviors of MWCNT nanocomposites decorated/deposited with silicon content was investigated using different techniques, viz.

Degradation of methyl orange on Fe/Ag nanoparticles immobilized on polyacrylonitrile nanofibers using EDTA chelating agents.

Bimetallic nanoparticles are effective for the removal of organic pollutants from environmental water samples through catalytic degradation reactions. Hence, this work reports on the preparation of Fe/Ag bimetallic nanoparticles immobilized on electrospun polyacrylonitrile nanofibers (PAN NFs) pre-functionalized with EDTA and ethylenediamine (EDA) chelating agents. Characterization techniques included attenuated total reflectance coupled to Fourier transform infrared spectrometer (ATR-FTIR), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), scanning electron microscopy (SEM) and thermogravimetric analysis (TGA).

Electronic structure and magnetic behaviors of exfoliated MoS nanosheets.

The correlation of electronic structure and magnetic behaviors of layered molybdenum disulfide (MoS) nanosheets, mechanically exfoliated from pristine hexagonal crystal (2H-MoS) have been studied. Raman spectra show the energy difference (ΔE) between two Raman peaks A and [Formula: see text] was about 20.2 cm, indicating the formation of mono-/bi-layered MoS nanosheets as obtained after mechanical exfoliation from pristine 2H-MoS .

Anisotropy in the magnetic interaction and lattice-orbital coupling of single crystal NiTeO.

This investigation reports on anisotropy in the magnetic interaction, lattice-orbital coupling and degree of phonon softening in single crystal NiTeO (NTO) using temperature- and polarization-dependent X-ray absorption spectroscopic techniques. The magnetic field-cooled and zero-field-cooled measurements and temperature-dependent Ni L-edge X-ray magnetic circular dichroism spectra of NTO reveal a weak Ni-Ni ferromagnetic interaction close to ~60 K (T: temperature of the onset of spin ordering) with a net alignment of Ni spins (the uncompensated components of the Ni moments) along the crystallographic c-axis, which is absent from the ab-plane. Below the Néel temperature, T~ 52 K, NTO is stable in the antiferromagnetic state with its spin axis parallel to the c-axis.

Correction: A high energy density asymmetric supercapacitor utilizing a nickel phosphate/graphene foam composite as the cathode and carbonized iron cations adsorbed onto polyaniline as the anode.

[This corrects the article DOI: 10.1039/C7RA12028A.].

Facile Synthesis of Nitrogen Doped Graphene Oxide from Graphite Flakes and Powders: A Comparison of Their Surface Chemistry.

Nitrogen-doped graphene oxide (NGO) nanosheets were prepared via a facile one-pot modified Hummer's approach at low temperatures using graphite powder and flakes as starting materials in the presence of a nitrogen precursor. It was found that the morphology, structure, composition and surface chemistry of the NGO nanosheets depended on the nature of the graphite precursor used. GO nanosheets doped with nitrogen atoms exhibited a unique structure with few thin layers and wrinkled sheets, high porosity and structural defects.

Conduction Mechanisms in Polyvinyl Alcohol: CdS/CdS:Cu Nanoparticle Hybrid Nanocomposites.

The electrical conduction mechanisms were investigated for the CdS and Cu-doped CdS (CdS:Cu) nanoparticles embedded in polyvinyl alcohol (PVA) (PVA/CdS and PVA/CdS:Cu) nanocomposites; synthesized by the chemical Sol Gel method on indium tin-oxide (ITO) substrate. X-ray diffraction pattern results show that the PVA/CdS nanocomposite is hawleyite-sturcture and PVA/CdS:Cu nanocomposites show greenockite-hawelyite mixed structure. The sizes of CdS and CdS:Cu nanoparticles were estimated from transmission electron microscopy (TEM) images and are ≈4 nm and ≈10 nm respectively; which were formed inside the PVA polymer layer.

Chemical Modification of Graphene Oxide by Nitrogenation: An X-ray Absorption and Emission Spectroscopy Study.

Nitrogen-doped graphene oxides (GO:N) were synthesized by a partial reduction of graphene oxide (GO) using urea [CO(NH)]. Their electronic/bonding structures were investigated using X-ray absorption near-edge structure (XANES), valence-band photoemission spectroscopy (VB-PES), X-ray emission spectroscopy (XES) and resonant inelastic X-ray scattering (RIXS). During GO:N synthesis, different nitrogen-bonding species, such as pyrrolic/graphitic-nitrogen, were formed by replacing of oxygen-containing functional groups.

Visualizing chemical states and defects induced magnetism of graphene oxide by spatially-resolved-X-ray microscopy and spectroscopy.

This investigation studies the various magnetic behaviors of graphene oxide (GO) and reduced graphene oxides (rGOs) and elucidates the relationship between the chemical states that involve defects therein and their magnetic behaviors in GO sheets. Magnetic hysteresis loop reveals that the GO is ferromagnetic whereas photo-thermal moderately reduced graphene oxide (M-rGO) and heavily reduced graphene oxide (H-rGO) gradually become paramagnetic behavior at room temperature. Scanning transmission X-ray microscopy and corresponding X-ray absorption near-edge structure spectroscopy were utilized to investigate thoroughly the variation of the C 2p(π*) states that are bound with oxygen-containing and hydroxyl groups, as well as the C 2p(σ*)-derived states in flat and wrinkle regions to clarify the relationship between the spatially-resolved chemical states and the magnetism of GO, M-rGO and H-rGO.

The effect of thermal reduction on the photoluminescence and electronic structures of graphene oxides.

Electronic structures of graphene oxide (GO) and hydro-thermally reduced graphene oxides (rGOs) processed at low temperatures (120-180°C) were studied using X-ray absorption near-edge structure (XANES), X-ray emission spectroscopy (XES) and resonant inelastic X-ray scattering (RIXS). C K-edge XANES spectra of rGOs reveal that thermal reduction restores C = C sp(2) bonds and removes some of the oxygen and hydroxyl groups of GO, which initiates the evolution of carbonaceous species. The combination of C K-edge XANES and Kα XES spectra shows that the overlapping π and π* orbitals in rGOs and GO are similar to that of highly ordered pyrolytic graphite (HOPG), which has no band-gap.

Graphene supported graphone/graphane bilayer nanostructure material for spintronics.

We report an investigation into the magnetic and electronic properties of partially hydrogenated vertically aligned few layers graphene (FLG) synthesized by microwave plasma enhanced chemical vapor deposition. The FLG samples are hydrogenated at different substrate temperatures to alter the degree of hydrogenation and their depth profile. The unique morphology of the structure gives rise to a unique geometry in which graphane/graphone is supported by graphene layers in the bulk, which is very different from other widely studied structures such as one-dimensional nanoribbons.

Atomistic nucleation sites of Pt nanoparticles on N-doped carbon nanotubes.

The atomistic nucleation sites of Pt nanoparticles (Pt NPs) on N-doped carbon nanotubes (N-CNTs) were investigated using C and N K-edge and Pt L3-edge X-ray absorption near-edge structure (XANES)/extended X-ray absorption fine structure (EXAFS) spectroscopy. Transmission electron microscopy and XANES/EXAFS results revealed that the self-organized Pt NPs on N-CNTs are uniformly distributed because of the relatively high binding energies of the adsorbed Pt atoms at the imperfect sites. During the atomistic nucleation process of Pt NPs on N-CNTs, stable Pt-C and Pt-N bonds are presumably formed, and charge transfer occurs at the surface/interface of the N-CNTs.

Silicon nanoparticle based fluorescent biological label via low temperature thermal degradation of chloroalkylsilane.

A simple low temperature colloid-chemical synthetic method is reported for size controlled synthesis of hydrophobic silicon nanoparticles in the 1-10 nm range. These silicon nanoparticles show size dependent tunable visible emission from blue to red with fluorescence quantum yield in the range of 6-13%. These silicon nanoparticles can be subjected to extensive surface chemistry without significant loss of their fluorescence properties.

Carbon nanoparticle-based fluorescent bioimaging probes.

Fluorescent nanoparticle-based imaging probes have advanced current labelling technology and are expected to generate new medical diagnostic tools based on their superior brightness and photostability compared with conventional molecular probes. Although significant progress has been made in fluorescent semiconductor nanocrystal-based biological labelling and imaging, the presence of heavy metals and the toxicity issues associated with heavy metals have severely limited the application potential of these nanocrystals. Here, we report a fluorescent carbon nanoparticle-based, alternative, nontoxic imaging probe that is suitable for biological staining and diagnostics.

Thiol-directed synthesis of highly fluorescent gold clusters and their conversion into stable imaging nanoprobes.

Fluorescent gold clusters (FGCs) with tunable emission from blue to red and quantum yields in the range of 6-17% have been synthesized by simple modification of the conditions used for the synthesis of gold nanoparticles, namely by replacing the stronger reducing agent with a controlled amount of thiol. Various functional FGCs with hydrodynamic diameters of 5-12 nm have been successfully synthesized and used as cell labels. The results of our investigations strongly indicate that FGCs composed of Au(0) are more stable imaging probes than commonly reported red/NIR-emitting FGCs with a composition of Au(0)/Au(I), as this combination rapidly transforms into nonfluorescent large clusters on exposure to light.