Correction: Facile fabrication of a graphene-based chemical sensor with ultrasensitivity for nitrobenzene.

[This corrects the article DOI: 10.1039/D3RA08794H.].

A DFT investigation on structural, electronic, magnetic, optical, elastic and hydrogen storage properties of Ru-based hydride-perovskites XRuH3 (X = Cr, V, Ni).

The present investigation delves into various physical properties exhibited by CrRuH3, VRuH3 and NiRuH3. Notably adopting a stable cubic configuration, both compounds manifest a distinct metallic demeanor characterized by an absolute absence of band gap. In-depth analysis through Total Density of States (TDOS) and Partial Density of States (PDOS) justify this metallic conduct by distinctly showcasing peak conductivity at the Fermi level. The materials' magnetic behavior reveals an antiferromagnetic disposition for CrRuH3 and NiRuH3, while their intrinsic attributes emerge as anisotropic and rigid. Applying Poisson's ratio (ν) and the B/G ratio, all investigated compounds show ductility, but the CrRuH3 is superior among them. The heightened values of Young's modulus, Bulk modulus, and mean shear modulus observed in CrRuH3 underscore its enhanced rigidity as compared to VRuH3 and NiRuH3. Within the optical realm, CrRuH3 displays notable optical conductivity and absorption, particularly within the lower energy spectrum. Remarkably, at 0 eV, CrRuH3 showcases elevated reflectivity and refractive index as compared to the other investigated materials. On the hydrogen storage front, XRuH3 (X = Cr, V, Ni) exhibit promising potential, yet CrRuH3 emerges as the more favorable candidate for hydrogen storage applications.

Facile fabrication of a graphene-based chemical sensor with ultrasensitivity for nitrobenzene.

Chemical sensors have a wide range of applications in a variety of industries, particularly for sensing volatile organic compounds. This work demonstrates the fabrication of a chemical sensor based on graphene deposited on Cu foils using low-pressure chemical vapor deposition, following its transfer on oxidized silicon through a wet etching method. Scanning electron microscopy, Raman spectroscopy and UV-vis spectroscopy of the transferred graphene were performed. A device was fabricated by simply connecting the strips of a Cu tape along the two opposite edges of graphene, which acted as a chemical sensor. The sensor was exposed to different analytes, namely acetone, propanol, benzyl chloride, nitrobenzene, carbon tetrachloride and acetic acid. A relative change in the resistance of the device was observed, which was attributed to the interaction of analytes with graphene as it changes charge concentrations in the graphene lattice. The fabricated sensor showed a notable sensitivity and response time for all analytes, particularly a sensitivity as high as 231.1 for nitrobenzene and a response time as short as 6.9 s for benzyl chloride. The sensor was also tested for analyte leakage from containers for domestic, laboratory and industrial applications.

Q-switched pulse operation in erbium-doped fiber laser subject to zirconia (ZrO2) nanoparticles-based saturable absorber.

In this paper, the zirconia (ZrO2) nanoparticles-based saturable-absorber (SA) have been incorporated in an erbium-doped fiber laser (EDFL) cavity for achieving a Q-switched pulse operation. The implementation of the zirconia nanoparticles-based powder on the fiber facet was accomplished using the index-matching gel's adhesion effect. The incorporation of SA in the laser cavity yielded a stable and self-starting Q-switched operation under 19.36 mW pump power that corresponded to the emission wavelength of 1557.29 nm. Additionally, it was observed that the EDFL's emission wavelength tuned from 1557.29 nm to 1562.3 nm , and the repetition rates and pulse width ranged from 61.2 to 130 kHz and 7.9 to 3.6 µs, respectively, as the pump power was increased from 19.36 to 380.16 mW. Measured experimental results reveal that at a maximum pump power of 380.16 mW, the maximum average output power, peak power, and pulse energy were noticed to be 1.17 mW, 2.5 mW, and 9 nJ, respectively. A 52 dB suppression in side bands was found at a pump power of 380.16 mW. Moreover, the stability and threshold tolerance of the EDFL has also been discussed in detail. These findings suggest that nanoparticle-based saturable absorbers have potential applications in a pulsed source, making it easier to implement in fiber cavity-based systems.

First-principles calculations to investigate structural, electronic, elastic and optical properties of radium based cubic fluoro-perovskite materials.

Perovskite materials play a vital role in the field of material science via experimental as well as theoretical calculations. Radium semiconductor materials are considered the backbone of medical fields. These materials are considered in high technological fields to be used as controlling the decay ability. In this study, radium-based cubic fluoro-perovskite XRaF3 (where X = Rb and Na) are calculated using a DFT (density functional theory). These compounds are cubic nature with 221 space groups that construct on CASTEP (Cambridge-serial-total-energy-package) software with ultra-soft PPPW (pseudo-potential plane-wave) and GGA (Generalized-Gradient-approximation)-PBE (Perdew-Burke-Ernzerhof) exchange-correlation functional. The structural, optical, electronic, and mechanical properties of the compounds are calculated. According to the structural properties, NaRaF3 and RbRaF3 have a direct bandgap with 3.10eV and 4.187eV of NaRaF3 and RbRaF3, respectively. Total density of states (DOS) and partial density of states (PDOS) provide confirmation to the degree of electrons localized in distinct bands. NaRaF3 material is semiconductors and RbRaF3 is insulator, according to electronic results. The imaginary element dispersion of the dielectric function reveals its wide variety of energy transparency. In both compounds, the optical transitions are examined by fitting the damping ratio for the notional dielectric function scaling to the appropriate peaks. The absorption and the conductivity of NaRaF3 compound is better than the RbRaF3 compound which make it suitable for the solar cell applications increasing the efficiency and work function. We observed that both compounds are mechanically stable with cubic structure. The criteria for the mechanical stability of compounds are also met by the estimated elastic results. These compounds have potential application in field of solar cell and medical. Objectives: The band gap, absorption and the conductivity are necessary conditions for potential applications. Here, literature was reviewed to check computational translational insight into the relationships between absorption and conductivity for solar cell and medical applications of novel RbRaF3 and NaRaF3 compounds.

Breast cancer chemical structures and their partition resolvability.

Cancer is a disease that causes abnormal cell formation and spreads throughout the body, causing harm to other organs. Breast cancer is the most common kind among many of cancers worldwide. Breast cancer affects women due to hormonal changes or genetic mutations in DNA. Breast cancer is one of the primary causes of cancer worldwide and the second biggest cause of cancer-related deaths in women. Metastasis development is primarily linked to mortality. Therefore, it is crucial for public health that the mechanisms involved in metastasis formation are identified. Pollution and the chemical environment are among the risk factors that are being indicated as impacting the signaling pathways involved in the construction and growth of metastatic tumor cells. Due to the high risk of mortality of breast cancer, breast cancer is potentially fatal, more research is required to tackle the deadliest disease. We considered different drug structures as chemical graphs in this research and computed the partition dimension. This can help to understand the chemical structure of various cancer drugs and develop formulation more efficiently.

Lithium-based perovskites materials for photovoltaic solar cell and protective rays window applications: a first-principle calculations.

Perovskites are the key enabler materials for the solar cell applications in the achievement of high performance and low production costs. In this article, the structural, mechanical, electronic, and optical properties of rubidium-based cubic nature perovskite LiHfO3 and LiZnO3 are investigated. These properties are investigated using density-functional theory with the aid of CASTEP software by introducing ultrasoft pseudo-potential plane-wave (USPPPW) and GG-approximation-PB-Ernzerhof exchange-correlation functionals. It is investigated that the proposed compounds exhibit stable cubic phase and meet the criteria of mechanical stability by the estimated elastic properties. Also, according to Pugh's criterion, it is noted that LiHfO3 is ductile and LiZnO3 is brittle. Furthermore, the electronic band structure investigation of LiHfO3 and LiZnO3 shows that they have indirect bandgap (BG). Moreover, the BG analysis of the proposed materials shows that these are easily accessible. Also, the results for partial density of states (DOS) and total DOS confirm the degree of a localized electron in the distinct band. In addition, the optical transitions in the compounds are examined by fitting the damping ratio for the notional dielectric functions scaling to the appropriate peaks. At absolute zero temperature, the materials are observed as semiconductors. Therefore, it is evident from the analysis that the proposed compounds are excellent candidates for solar cells and protective rays applications.

Computing the partition dimension of certain families of Toeplitz graph.

Let G = (V(G), E(G)) be a graph with no loops, numerous edges, and only one component, which is made up of the vertex set V(G) and the edge set E(G). The distance d(u, v) between two vertices u, v that belong to the vertex set of H is the shortest path between them. A k-ordered partition of vertices is defined as ß = {ß1, ß2, …, ß k }. If all distances d(v, ß k ) are finite for all vertices v ∈ V, then the k-tuple (d(v, ß1), d(v, ß2), …, d(v, ß k )) represents vertex v in terms of ß, and is represented by r(v|ß). If every vertex has a different presentation, the k-partition ß is a resolving partition. The partition dimension of G, indicated by pd(G), is the minimal k for which there is a resolving k-partition of V(G). The partition dimension of Toeplitz graphs formed by two and three generators is constant, as shown in the following paper. The resolving set allows obtaining a unique representation for computer structures. In particular, they are used in pharmaceutical research for discovering patterns common to a variety of drugs. The above definitions are based on the hypothesis of chemical graph theory and it is a customary depiction of chemical compounds in form of graph structures, where the node and edge represent the atom and bond types, respectively.

Wettability-defined droplet imbibition in ceramic mesopores.

Wettability-defined liquid infiltration into porous materials in nature and several industrial applications is of fundamental interest. Direct observation of wetting-controlled imbibition in mesopores is anticipated to deliver important insights into the interplay between nanoconfined liquid movement and nanoscale wettability. We present a systematic study of water imbibition into mesoporous silica thin films with wetting properties precisely adjusted through chemical functionalization. We observe the liquid infiltration, resulting in an imbibition ring around the water droplet, by top-view imaging using a camera with collimated coaxial illumination. With decreasing hydrophilicity, the maximum imbibition area around the droplet decreases, accompanied by a simultaneous change in the imbibition kinetics and imbibition mechanism. Initially, the imbibition kinetics follow a modified Lucas-Washburn law that considers a strong influence of evaporation. However, with increasing imbibition time after reaching constant imbibition ring dimensions, the imbibition area starts to increase again, causing a deviation from the applied model. This observation is ascribed to water-mediated surface activation at the imbibition front, leading to a slightly increased wettability, which is also confirmed by water adsorption measurements. Furthermore, recently described spontaneous condensation-evaporation imbalances that cause oscillations of the imbibition front could be verified and were studied with regard to changing wetting properties. By increasing the contact angle of the material and therefore the partial pressure needed for capillary condensation, the amplitude of the imbibition front oscillations decreases. These results provide insights into the wettability-defined complex movement of water in mesoporous structures, which has practical implications, e.g., for nano/microfluidic devices and water purification or harvesting.

Insights into the interplay of wetting and transport in mesoporous silica films.

The understanding and design of wetting-transport and wetting-charge-transport interplay in nanometer-sized pores is a still not fully understood key step in improving nanopore transport-related applications. A control of mesopore wettability accompanied by pore filling and ionic mesopore accessibility analysis is expected to deliver major insights into this interplay of nanoscale pore wetting and transport. For a systematic understanding, we demonstrate a gradual adjustment of nanopore ionic accessibility by gradually tuning silica nanopore wettability using chemical vapor phase deposition of 1H,1H,2H,2H-perfluorooctyl dimethylchlorosilane. The mutual influence of wetting on liquid imbibition, condensation, and molecular transport as well as on heat transfer were studied by ellipsometry, cyclic voltammetry and boiling experiments, respectively. A multi-methodical analytic approach was used to directly couple wetting properties of mesoporous silica thin films to ionic mesopore accessibility allowing us to determine two different ion transport mechanisms based on three defined wetting regimes as well as a threshold hydrophobicity suppressing pore accessibility. Furthermore, boiling experiments showed a clear increase in nucleation site density upon changing the wettability of the mesoporous surfaces from hydrophilic to hydrophobic. Hence, these results provide insights into the complex interplay of pore wall functionalization, wetting, and charge-dependent nanopore properties.

Synthesis of Ni9S8/MoS2 heterocatalyst for Enhanced Hydrogen Evolution Reaction.

We demonstrate a heterostructure Ni9S8/MoS2 hybrid with tight interface synthesized via an improved hydrothermal method. As compared to pure MoS2, the increased surface area and the shorten charge transport pathway in the layered hybrid significantly promote the photocatalytic efficiency for hydrogen evolution reaction (HER). In particularly, the optimized Ni9S8/MoS2 hybrid with 20 wt % Ni9S8 exhibits the highest photocatalytic activity with HER value of 406 µmolg-1h-1, which is enhanced by 70% compared to that of pure MoS2 nanosheets (285.0 µmolg-1h-1). Moreover, the value is 4 times more than the commercial MoS2 (92.0 µmolg-1h-1), indicating the high potential of the hybrid in the catalytic fields.

Vertical 1T-MoS2 nanosheets with expanded interlayer spacing edged on a graphene frame for high rate lithium-ion batteries.

Vertical 1T-MoS2 nanosheets with an expanded interlayer spacing of 9.8 Å were successfully grown on a graphene surface via a one-step solvothermal method. Such unique hybridized structures provided strong electrical and chemical coupling between the vertical nanosheets and graphene layers by means of C-O-Mo bonding. The merits are very beneficial for a high-efficiency electron/ion transport pathway and structural stability. As a proof of concept, the lithium ion battery with the as-obtained hybrid's electrode exhibited excellent rate performance with a 666 mA h g-1 capacity at a high current density of 3500 mA g-1. We can extend this method to produce various metallic 1T-MX2 (M = transition metal; X = chalcogen) vertically edged on a graphene frame as one of the promising hetero-structures for several specific applications in the fields of electronics, optics and catalysis.

Stable 1T-MoSe2 and Carbon Nanotube Hybridized Flexible Film: Binder-Free and High-Performance Li-Ion Anode.

Two-dimensional stable metallic 1T-MoSe2 with expanded interlayer spacing of 10.0 Å in situ grown on SWCNTs film is fabricated via a one-step solvothermal method. Combined with X-ray absorption near-edge structures, our characterization reveals that such 1T-MoSe2 and single-walled carbon nanotubes (abbreviated as 1T-MoSe2/SWCNTs) hybridized structure can provide strong electrical and chemical coupling between 1T-MoSe2 nanosheets and SWCNT film in a form of C-O-Mo bonding, which significantly benefits a high-efficiency electron/ion transport pathway and structural stability, thus directly enabling high-performance lithium storage properties. In particular, as a flexible and binder-free Li-ion anode, the 1T-MoSe2/SWCNTs electrode exhibits excellent rate capacity, which delivers a capacity of 630 mAh/g at 3000 mA/g. Meanwhile, the strong C-O-Mo bonding of 1T-MoSe2/SWCNTs accommodates volume alteration during the repeated charge/discharge process, which gives rise to 89% capacity retention and a capacity of 971 mAh/g at 300 mA/g after 100 cycles. This synthetic route of a multifunctional MoSe2/SWCNTs hybrid might be extended to fabricate other 2D layer-based flexible and light electrodes for various applications such as electronics, optics, and catalysts.

Evaluation of Medical Image Registration Techniques Based on Nature and Domain of the Transformation.

A lot of research has been done during the past 20 years in the area of medical image registration for obtaining detailed, important, and complementary information from two or more images and aligning them into a single, more informative image. Nature of the transformation and domain of the transformation are two important medical image registration techniques that deal with characters of objects (motions) in images. This article presents a detailed survey of the registration techniques that belong to both categories with detailed elaboration on their features, issues, and challenges. An investigation estimating similarity and dissimilarity measures and performance evaluation is the main objective of this work. This article also provides reference knowledge in a compact form for researchers and clinicians looking for the proper registration technique for a particular application.

Gram-Scale Aqueous Synthesis of Stable Few-Layered 1T-MoS2 : Applications for Visible-Light-Driven Photocatalytic Hydrogen Evolution.

Most recently, much attention has been devoted to 1T phase MoS2 because of its distinctive phase-engineering nature and promising applications in catalysts, electronics, and energy storage devices. While alkali metal intercalation and exfoliation methods have been well developed to realize unstable 1T-MoS2 , but the aqueous synthesis for producing stable metallic phase remains big challenging. Herein, a new synthetic protocol is developed to mass-produce colloidal metallic 1T-MoS2 layers highly stabilized by intercalated ammonium ions (abbreviated as N-MoS2). In combination with density functional calculations, the X-ray diffraction pattern and Raman spectra elucidate the excellent stability of metallic phase. As clearly depicted by high-angle annular dark-field imaging in an aberration-corrected scanning transmission electron microscope and extended X-ray absorption fine structure, the N-MoS2 exhibits a distorted octahedral structure with a 2a0 × a0 basal plane superlattice and 2.72 Å Mo-Mo bond length. In a proof-of-concept demonstration for the obtained material's applications, highly efficient photocatalytic activity is achieved by simply hybridizing metallic N-MoS2 with semiconducting CdS nanorods due to the synergistic effect. As a direct outcome, this CdS:N-MoS2 hybrid shows giant enhancement of hydrogen evolution rate, which is almost 21-fold higher than pure CdS and threefold higher than corresponding annealed CdS:2H-MoS2.

Stable Metallic 1T-WS2 Nanoribbons Intercalated with Ammonia Ions: The Correlation between Structure and Electrical/Optical Properties.

Stable metallic 1T-WS2 nanoribbons with zigzag chain superlattices, highly stabilized by ammonia-ion intercalation, are produced using a facile bottom-up process. The atomic structure of the nanoribbons, including W-W reconstruction and W-S distorted octahedral coordination, results in distinctive electrical transport and optical Raman scattering properties that are very different from semiconducting 2H-WS2 . The correlations between structure and properties are further confirmed by theory calculations.

Ultrathin carbon layer coated MoO2 nanoparticles for high-performance near-infrared photothermal cancer therapy.

Carbon layer-coated molybdenum dioxide nanoparticles exhibit strong photo-absorption in the near infrared (NIR) region with good photostability. The in vitro and in vivo experiments reveal that an excellent photothermal ablation induced from the nanoparticle agents under NIR irradiation can kill tumor cells not only at the cellular level but also in living organs.