Nanoflakes Research Articles

Facile synthesis of ZnTiO3 nanoflakes as an efficient electrode material for high energy density supercapacitor applications

Nanocomposite electrode materials have gained much interest in supercapacitor applications because of their exceptional energy storage performance. In this pursuit, the current work reports a low cost, facile, hydrothermal synthesis of crystalline ZnTiO3 nanoflakes (NFs) as an efficient electrode for supercapacitors. The phase formation and degree of functionalization of as-synthesized ZnTiO3 nanoflakes were confirmed using XRD and FT-IR spectroscopic analysis. The hierarchical ZnTiO3 nanoflakes annealed at 600⸰C consisting of Zn wrapped with TiO2 surface are confirmed using FE-SEM and HR-TEM images. The synthesized symmetric ZnTiO3 NFs in 6 M KOH electrolyte exhibits a high specific capacitance of 132 F/g at the current rate of 1 A/g with outstanding rate performance and excellent electrochemical stability of 85 % for 10,000 cycles at a high current density of 5 A/g. The fabricated asymmetric solid-state ZnTiO3/Activated carbon (AC) supercapacitor shows 240 F/g at 1 A/g current density in a single cell with an outstanding energy density of 27 Wh/kg at a power density of 962 W/kg. High performance in supercapacitors application is largely due to the synergistic effect of ZnTiO3 intercalation during the electrochemical reaction. In the demonstration, LEDs are connected to the device, and power is delivered rapidly. As a result of its excellent electrical conductivity, low cost, and environmental friendly properties, ZnTiO3 is a potential candidate for use in energy storage and electrochemical sensors in the future.

Jute stick extract assisted hydrothermal synthesis of zinc oxide nanoflakes and their enhanced photocatalytic and antibacterial efficacy

• Hot extraction of jute stick. • A green hydrothermal approach to synthesize ZnO nanoflakes using jute stick extract. • Prepared jute extrcact assisted ZnO nanoflakes showed a significant dye degradation. • 98 % efficiency in MB degradation was calcualted after 8 h of UV light irradiation. • Prepared jute supported ZnO exhibited 19 mm of zone inhibition against E. coli. In this paper, we used green and hydrothermal methodology to prepare zinc oxide (ZnO) nanoflakes (NFs) with jute stick extract (J–ZnO NFs) as growth substrate. The prepared materials were characterized using different analytical techniques including ultraviolet–visible spectroscopy (UV–vis), X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), thermogravimetric analysis (TGA), fourier transform infrared (FTIR) spectroscopy, and X-ray photoelectron spectroscopy (XPS). The characteristic absorption peak for ZnO NFs and J–ZnO NFs were observed from the UV–vis spectrum at 373 and 368 nm respectively. The hexagonal wurtzite crystal structure of ZnO NFs and J–ZnO NFs was confirmed by XRD analysis. FESEM and TEM analyses of synthesized J–ZnO NFs confirmed their NFs shape and collectively flower-like structure formation by the assembly of NFs of J–ZnO on cellulose of jute stick extract substrate. The FTIR analysis revealed the functional groups of jute stick extract biomolecules, mainly cellulose, are responsible for the formation of collectivel flower like J–ZnO NFs structure. The XPS analysis revealed the surface and chemical compositions (Zn, C, and O) of J–ZnO NFs. The photocatalytic performance of ZnO NFs and J–ZnO NFs samples was carried out by the degradation of methylene blue (MB) dye solution under UV light irradiation. The degradation efficiency of ZnO NFs and J–ZnO NFs was obtained 79 % and 89 %, respectively, for 5 h. Notably, the degradation efficiency of the J–ZnO NFs was 98 % after 8 h of irradiation, which is very inspiring. The both NFs exhibited first-order kinetics with MB photodegradation. We also examined the possible antibacterial activity of both samples against Escherichia coli (E. coli) pathogens, which demonstrated a significant result with a 17 mm and 19 mm zone of inhibition by ZnO NFs and J–ZnO NFs respectively.

Efficient lock-in CuO/WON heterostructures tailored for highly sensitive electrochemical detection of hazardous herbicide diuron in fruit juices and aqua region

A micro-nano lock-in heterostructure has attracted significant attention for electrochemical sensor application due to its high specific surface area, more exposed active sites, and fast ion transport. Despite these advantages, here we prepared lock-in hetero structured tungsten oxynitride (WON) with a flower of CuO architecture by using the impregnation method. The tungsten oxynitride (WON) was prepared from the doping of nitrogen over the lattice of WO3 via a reactive NH3 gas etching process which turns WO3 nanoflakes (NFs) into the WON etched nanoflakes (EFs). The EFs act as cages to hold the hydrothermally prepared CuO micro flowers (MFs) and forms a new type of ‘lock-in’ heterostructure. This structure enables the stable and faster charge transfer between the CuO MFs and WON EFs, resulting in an efficient electrochemical performance towards the detection of diuron herbicide. The prepared CuO/WON were subjected to physiochemical characterizations such as X-ray diffraction (XRD), Raman spectroscopy, and X-ray photoelectron spectroscopy (XPS). The morphological and elemental information was interpreted by field-emission scanning electron microscopy (FESEM) combined with EDX and mapping analysis. Then, CuO/WON/GCE sensor electrode exhibited a wide diuron (DU) detection range of about 0.01–764.4 µM. Moreover, the estimated limit of detection and sensitivity from the slope of DU detection is 5.5 nm and 0.445 µM µA−1 cm−2 respectively. The practical applicability of the sensor electrodes was tested in the DU-added grape juice, orange juice, tap water, and river water samples.

Emergence of electric field-induced conducting states in single-crystalline MoTe[formula omitted] nanoflakes and its application in memristive devices

Conductive atomic force microscopy (cAFM) reveals the emergence of conducting states in MoTe2 NFs under applied electric field. In this report, we explore the use of electric field induced conducting states in the single-crystalline MoTe2 nanoflakes (NFs) for nonvolatile resistive memory technologies. The memristive devices are fabricated in vertical metal–insulator (active layer)-metal architecture with aluminum top and fluorine doped tin oxide bottom electrodes. The MoTe2 NFs were embedded in polymethyl methacrylate (PMMA) to form the active layer. The device shows appreciable resistive switching (RS) characteristics while switching from a high resistive state (HRS) to a low resistive state (LRS) and vice versa. The low-frequency conductance noise (LFCN) measurements show that the power spectral density of conductance fluctuation follows the 1/f2 nature in the HRS, while 1/f in LRS. The stochastic analysis of conductance fluctuation data exhibits random telegraphic noise in the HRS, indicating the role of NFs as charge trapping sites. The LFCN measurements and cAFM study confirm that electric field-induced conducting states are pivotal in enhancing the RS performance of the memory device.

Flower-like NiCo2O4 nanoflake surface covered on carbon nanolayer for high-performance electro-oxidation of non-enzymatic glucose biosensor

The high porous nickel cobalt oxide flower-like nanoflake (NF) structured materials with (C/NiCo2O4-1 and C/NiCo2O4-2) and without (NiCo2O4) the presence of dopamine as a carbon source were synthesized by a simple hydrothermal method for non-enzymatic glucose sensing. The structural and morphological characteristics of as-synthesized materials were confirmed using transmission electron microscopy, field emission scanning electron microscopy, X-ray photoelectron spectroscopy, and X-ray diffraction analysis. The transmission electron microscopy analysis of C/NiCo2O4-1 NF materials reveals that a flower-like structure of NiCo2O4 NF covered over the surface of carbon in the hybrid composite. The electrochemical properties of as-synthesized material were determined from cyclic voltammetry and chronoamperometry analysis. Among the NiCo2O4 NF, C/NiCo2O4-1 NF, and C/NiCo2O4-2 NF structured materials, the C/NiCo2O4-1 NF exhibits a remarkable electrochemical performance toward glucose oxidation with a high linear range (0.0001–15.28 mM), high-sensitivity (779.35 μA mM−1 cm−2), and ultra-low detection (86 μM). Moreover, the C/NiCo2O4-1 NF electrode indicates excellent recoveries of glucose in human blood serum samples. The obtained results illustrate that the good features of C/NiCo2O4-1 NF electrode materials have the potential to be used as a non-enzymatic glucose sensor.

An ultra-sensitive dual-signal ratiometric electrochemical aptasensor based on functionalized MOFs for detection of HER2

The dual-signal radiometric sensor can effectively reduce the difference between repeated detection and achieve higher accuracy, sensitivity and repeatability detection. In this work, we constructed a simple ratiometric electrochemical aptasensor based on functionalized ZIF-67 and ZIF-90 for sensitive detection of human epidermal growth factor receptor-2 (HER2). ZIF-67@Ferrocene (Fc)/antimonate nano flakes (AMNFs) as the capture probe has a large specific surface area and good conductivity, and have a strong adsorption capacity for aptamer single-stranded deoxyribonucleic acid (ssDNA). When the biomarker - HER2 interacts with aptamer ssDNA, it is easily desorbed from its surface. At the same time, ZIF-90@ methylene blue (MB) as the signal probe realizes one-step encapsulation of MB signal, which can avoid interference from external environment. When the target-HER2 exists, it is recognized by the capture probe, which leads to the decrease of the conductivity of the electrode. Under the action of the signal probe, the conductivity of the signal is recovered and the detection signal is amplified significantly. The designed ratiometric electrochemical aptasensor showed a wide linear range (0.5–1000 pg mL−1) and a low detection limit (155 fg mL−1) for HER2. Subsequently, it was applied to actual serum samples and showed acceptable applicability. It shows great potential for clinical screening and immediate detection of cancer biomarkers.

Band gap and Morphology Engineering of Hematite Nanoflakes from an Ex Situ Sn Doping for Enhanced Photoelectrochemical Water Splitting.

In this article, we report a simple ex situ Sn-doping method on hematite nanoflakes (coded as MSnO2-H) that can protect the nanoflake (NF) morphology against the 800 °C high-temperature annealing process and activate the photoresponse of hematite until 800 nm wavelength excitation. MSnO2-H has been fabricated by dropping SnCl4 ethanol solution on hematite nanoflakes homogeneously grown over the conductive FTO glass substrate and annealed at 500 °C to synthesize the SnO2 nanoparticles on hematite NFs. The Sn-treated samples were then placed in a furnace again, and the sintering process was conducted at 800 °C for 15 min. During this step, structure deformation of hematite occurs normally due to the grain boundary motion and oriented attachment. However, in the case of MSnO2-H, the outer SnO2 nanoparticles efficiently prevented a shape deformation and maintained the nanoflake shape owing to the encapsulation of hematite NFs. Furthermore, the interface of hematite/SnO2 nanoparticles became the spots for a heavy Sn ion doping. We demonstrated the generation of the newly localized states, resulting in an extension of the photoresponse of hematite until 800 nm wavelength light irradiation. Furthermore, we demonstrated that SnO2 nanoparticles can effectively act as a passivation layer, which can reduce the onset potential of hematite for water splitting redox reactions. The optimized MSnO2-H nanostructures showed a 2.84 times higher photocurrent density and 300 mV reduced onset potential compared with a pristine hematite nanoflake photoanode.

Structures and optical properties of CdSe nano flakes synthesized by an elemental direct reaction method

CdSe nano flakes have been synthesized through using the selenium powder and cadmium foil in the ethylenediamine by an elemental direct reaction method. These high-quality CdSe nano flakes, being approximately perpendicular to the cadmium foil substrate, show the hexagonal structure and are characterized with the networking structures. According to Kubelka-Munk method, band gap of CdSe nano flakes can be estimated to be ∼2.44 eV. Multi-peak emissions under the excitation of 325 nm can be observed at room temperature. From green to red, four emissions can be fitted and attributed to the transition of band gap, selenium vacancies, interstitial cadmium, and the surface defects associated with oxygen, respectively. Investigation of multi-peak emission origins as well as understanding and regulating of defect states are helpful for CdSe nano flakes to apply in the field of the optoelectronic devices.

Mo3Se4 nanoparticle with ROS scavenging and multi-enzyme activity for the treatment of DSS-induced colitis in mice

Ulcerative colitis (UC), as a most common inflammatory bowel disease (IBD), has become a global public health concern. Exploring novel method of treating UC is urgent and necessary. Recently, nanozyme with excellent antioxidant properties may be one useful therapeutic strategy. In this study, a two-dimensional transition metal chalcogenide (TMCs) nano flake and polyethylene glycol (PEG) modified Mo3Se4 nano flakes (PMNFs) was synthesized, which had multi-enzyme activity, including peroxidase, glutathione peroxidase (GPx), superoxide dismutase (SOD), and catalase (CAT). The inhibition effect of PMNFs on sodium dextran sulfate (DSS)-induced colitis was explored. UC was effectively inhibited by PMNFs in this work. PMNFs significantly reduced disease activity index (DAI) score, including weight loss, colon shorten and histopathological abnormalities. The possible mechanism of PMNFs-attenuated colitis was investigated. The results showed that PMNFs reversed DSS-induced oxidative damage, and the antioxidant pathway Nrf2-keap1 signal was activated by PMNFs. Moreover, PMNFs suppressed the expression of pro-inflammatory factors including IL-1β, TNF-α, IFN-β and IL-6 via the inactivation of TLR4/NF-κB pathway in DSS-induced colitis and LPS-treated macrophage. Furthermore, PMNFs treatment prevented the reduction of tight junction proteins (ZO-1, occludin, and claudin-1) and mucin-2 (MUC-2) as well as the up-regulation of epithelial apoptosis caused by DSS. These findings demonstrate that the PMNFs against DSS-induced colitis due to its prevention on oxidative damage, inflammation, and intestine barrier breakdown. Thus, PMNFs have a potential application in the treatment of various oxidative stress or inflammation-related diseases.

Efficient charge storage by ZnCo2S4 nanoflakes@MgCo2O4 nanorods composite in Mg2+/Zn2+/K+ conducting electrolytes

Heretofore unreported, a unique binder free composite cathode of zinc cobalt sulfide nanoflakes (NFs) and magnesium cobaltite nanorods (NRs) (ZnCo2S4@MgCo2O4) is presented and its potential for efficient energy storage is realized in terms of (1) a high electrical conductivity of ~0.7 mS cm−1 imparted by the mixed-valence states of Co2+/Co3+, (2) the mesoporous structure of the MgCo2O4 NRs enabling fast ion-diffusion and (3) the 3D ZnCo2S4 flakes with large exposed facets that allow abundant electrolyte-electroactive site-interactions. These factors cumulatively result in a high specific capacitance (SC) of 609 F g−1 (at 1.25 A g−1), Emax of 217 Wh kg−1 and a Pmax of 8 kW kg−1 over a voltage window of 1.6 V along with a cycle life of 10,000 cycles with 98 % SC retention for the ZnCo2S4@MgCo2O4//AC asymmetric supercapacitor (ASC) with KOH as the electrolyte. These performance metrics are superior to those reported in literature for similar oxides/chalcogenides. The electrolyte's role in controlling the redox-behaviour of the ASC is also assessed by using four different uni-molar electrolytes that obey the following order: KOH > Mg(OH)2 > MgCl2 > ZnCl2, in terms of their ionic conductivities (σ: 189, 84, 83 and 58 mS cm−1), cation transport number (t+: 0.85, 0.83, 0.75 and 0.57) and SCs (609, 315, 208, 100 F g−1 at 1.25 A g−1) for the corresponding ASCs. With the KOH electrolyte, a dominant contribution from diffusional transport (68 %) relative to the capacitive double layer storage (32 %) (at 10 mV s−1) is ascertained which confirms the ZnCo2S4@MgCo2O4 composite's ability to exhibit facile Faradaic reactions for charge storage, thereby aligning with the morphological and spinel structure benefits. A green-LED-illumination with a 3S(series)-configuration encompassing three-fully-charged ASCs, further validates this configuration's applicability for niche applications in consumer-electronic-devices.

Nonlinear Coherent Light–Matter Interaction in 2D MoSe2 Nanoflakes for All‐Optical Switching and Logic Applications

AbstractA strong nonlinear optical response of 2D MoSe2 nanoflakes (NFs) through spatial self‐phase modulation (SSPM) and cross‐phase modulation (XPM) induced by nonlocal coherent light–matter interactions is reported. The coherent interaction of light and MoSe2 NFs creates the SSPM of laser beams, forming concentric diffraction rings. The nonlinear refractive index (n2) and third‐order broadband nonlinear optical susceptibility (χ(3)) of MoSe2 NFs are determined from the self‐diffraction pattern at different exciting wavelengths of 405, 532, and 671 nm with varying laser intensity. The evolution and deformation of diffraction ring patterns are observed and analyzed by the “wind‐chime” model and thermal effect. By taking advantage of the reverse saturated absorption of 2D SnS2 NFs compared to MoSe2, an all‐optical diode has been designed with MoSe2/SnS2 hybrid structure to demonstrate the nonreciprocal light propagation. Few other optical devices based on MoSe2 and semiconducting materials such as Bi2Se3, CuPc, and graphene have been investigated. The all‐optical logic gates and all‐optical information conversion have been demonstrated through the XPM technique using two laser beams. The proposed optical scheme based on MoSe2 NFs has been demonstrated as a potential candidate for all‐optical nonlinear photonic devices such as all‐optical diodes and all‐optical switches.

Simple Fabrication of Photodetectors Based on MoS2 Nanoflakes and Ag Nanoparticles.

Low-dimensional transition-metal dichalcogenides (TMDs) have recently emerged as promising materials for electronics and optoelectronics. In particular, photodetectors based on mono- and multilayered molybdenum disulfide (MoS2) have received much attention owing to their outstanding properties, such as high sensitivity and responsivity. In this study, photodetectors based on dispersed MoS2 nanoflakes (NFs) are demonstrated. MoS2 NFs interact with Ag nanoparticles (NPs) via low-temperature annealing, which plays a crucial role in determining device characteristics such as good sensitivity and short response time. The fabricated devices exhibited a rapid response and recovery, good photo-responsivity, and a high on-to-off photocurrent ratio under visible light illumination with an intensity lower than 0.5 mW/cm2.

Structural and Morphological Studies on Strontium Tin Phosphate SrSn(PO4)2 Nanopowder

Strontium Tin phosphate SrSn(PO4)2 nanopowder was prepared by simple Solid State Reaction method (SSR). Structural and morphological investigations of the synthesized nanopowder were characterized by Powdered X-ray diffraction study (P-XRD), Fourier transform infrared (FT-IR) Spectroscopy, Field Emission Scanning Electron Microscopy (FE-SEM) and Energy Dispersive X-ray Spectroscopy Analysis (EDS). The average crystallite size estimated from P-XRD study was around 17 nm. W-H plot method was also agreed the size of the crystallite of the prepared sample in nanoscale. FE-SEM images show agglomerates of non-uniform biscuit like nano flakes structure. Various functional groups of prepared sample exhibited phosphate related bands are confirmed by FT-IR study.

Sonochemically Prepared GdWNFs/CNFs Nanocomposite as an Electrode Material for the Electrochemical Detection of Antibiotic Drug in Water Bodies

The work demonstrates the development of an electrochemical sensor for quantification of Chloramphenicol (CA) using pencil graphite electrode (PGE) modified with Gadolinium tungstate nano flakes and carbon nano fibers composite (PGE/GWNfs/CNFs). The composite was further characterized and confirmed by X-ray diffraction (XRD), energy-dispersive X-ray spectroscopy, transmission electron microscopy analysis. The prepared GWNfs/CNFs nano composite was fabricated by drop casting method to get PGE/GWNfs/CNFs working electrode. The modified electrode is then analyzed by cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS) and differential pulse voltammetry (DPV) methods for its electrochemical and electrocatalytic property. The electrochemical investigation of developed sensor shows enhanced activity towards electro-oxidation of CA. The DPV studies revealed high efficacy characteristics such as sensitivity in the range 0.03984 µA µM−1 cm−2, selectivity, good linear range (5–50 μM), and low detection limit (0.4 μM). The study benchmarks the use of GWNfs/CNFs as an excellent transducer material in electrochemical sensing of CA in standard samples thus, it finds an efficient potential application in the analysis of CA in environment sample analysis.

Effect of binder on the performance of zinc‐tin‐sulfide nano flakes for the high‐performance supercapattery devices

Here in this work, we report the role of binder concentration on the electrochemical performance of Zn-Sn-S (ZTS) mesoporous material for high-performance supercapattery devices. The desired material is synthesized through the facile hydrothermal technique followed by ultra-sonication for 1 h. Material’s morphology, crystallinity, porosity, surface area, elemental analysis, and composition were analyzed through field emission scanning electron microscopy (FESEM), X-ray diffraction (XRD), scanning transmission electron microscopy (STEM), Brunauer-Emmett-Teller (BET), Fourier transform infrared spectroscopy (FTIR), and X-ray photoelectron spectroscopy (XPS). The effect of binder concentration on the electrochemical properties was investigated by performing cyclic voltammetry (CV), galvanostatic charge-discharge (GCD), and electrochemical impedance spectroscopy (EIS) in three-electrode assembly while maintaining the 1 M KOH electrolyte environment. In three-electrode setup, the electrodes with a binder concentration of 50%, 25%, and 10% show a specific capacity of 69.24, 154.17, and 247.91 C/g at the current density of 1.0 A/g. Correspondingly, the series resistance observed in EIS for these three electrodes are 3.27, 2.12 and 1.29 Ω, which suggests that ZTS with 10% nafion possesses better electrochemical properties. Therefore, the electrode with a 10% binder concentration was then coupled with the activated carbon to assemble a supercapattery. This assembly (ZTS//AC) was then characterized with CV, GCD, and EIS, which delivers a specific capacity of 135.27 C/g, energy density of 30.06 Wh/kg, and 3200 W/kg of power density. At last, the device's cyclic life had been investigated by initiating GCD for 2500 continuous cycles at the current density of 3.0 A/g. We found that the material’s performance significantly got affected by the binder concentration, and it showed better performance with the optimized concentration of the binder. Furthermore, the ZTS material can be utilized as an appealing electrode material for future supercapattery devices that can deliver a high energy and power density because the material had shown a stable behavior at higher current densities.

Photogenerated reactive oxygen species and hyperthermia by Cu3SnS4 nanoflakes for advanced photocatalytic and photothermal antibacterial therapy

BackgroundThe rapid spread of infectious bacteria has brought great challenges to public health. It is imperative to explore effective and environment-friendly antibacterial modality to defeat antibiotic-resistant bacteria with high biosafety and broad-spectrum antibacterial property.ResultsHerein, biocompatible Cu3SnS4 nanoflakes (NFs) were prepared by a facile and low-cost fabrication procedure. These Cu3SnS4 NFs could be activated by visible light, leading to visible light-mediated photocatalytic generation of a myriad of reactive oxygen species (ROS). Besides, the plasmonic Cu3SnS4 NFs exhibit strong near infrared (NIR) absorption and a high photothermal conversion efficiency of 55.7%. The ROS mediated cellular oxidative damage and the NIR mediated photothermal disruption of bacterial membranes collaboratively contributed to the advanced antibacterial therapy, which has been validated by the efficient eradication of both Gram-negative Escherichia coli and Gram-positive methicillin-resistant Staphylococcus aureus strains in vitro and in vivo. Meanwhile, the exogenous copper ions metabolism from the Cu3SnS4 NFs facilitated the endothelial cell angiogenesis and collagen deposition, thus expediting the wound healing. Importantly, the inherent localized surface plasmon resonance effect of Cu3SnS4 NFs empowered them as an active substrate for surface-enhanced Raman scattering (SERS) imaging and SERS-labeled bacteria detection.ConclusionsThe low cost and biocompatibility together with the solar-driven broad-spectrum photocatalytic/photothermal antibacterial property of Cu3SnS4 NFs make them a candidate for sensitive bacteria detection and effective antibacterial treatment.Graphical

Boronic Acid Decorated Graphene Nano Flakes for Glucose Sensing in Diabetes: A DFT Prediction

The requirement of high-sensitivity, accurate and rapid determination of glucose in human blood is major challenge from clinical perspective. In this work, boronic acids (BAs) and derivatives were successfully functionalized over graphene nano flakes (GNF) surface as a sensing platform to spot Glucose molecule. The density functional theory-based investigation has been carried out by considering geometrical optimization, density of states, and molecular energy spectrum. Further, molecular properties like molecular orbital investigations, energy gap, chemical hardness, chemical softness, have been evaluated in order to distinguish the rate of reaction and binding energy between GNF-BA and Glucose. Results show that BAs derivatives were physisorbed/chemisorbed over GNF surface. Moreover, the analyte formed the covalent interactions with its diol group towards the trigonal structured B atom of BAs and provided the sensing signal by modifying the DOS peaks of sensing platform. Eventually, the sensitivity of different BA’s derivatives @GNF to Glucose sensing were compared. These findings show the variation at molecular and atomic level behaviour of GNF-BA sensing platform in presence/absences of Glucose. Therefore, our DFT predictions have application in designing sensor in area of biomolecules and bioelectronics for healthcare sector.

Engineering Hibiscus-Like Riboflavin/ZIF-8 Microsphere Composites to Enhance Transepithelial Corneal Cross-Linking.

Riboflavin-5-phosphate (RF) is the most commonly used photosensitizer in corneal cross-linking (CXL), but its hydrophilicity and negative charge limit its penetration through the corneal epithelium into the stroma. To enhance the corneal permeability of RF and promote its efficacy in the treatment of keratoconus, novel hibiscus-like RF@ZIF-8 microsphere composites [6RF@ZIF-8 NF (nanoflake)] are prepared using ZIF-8 nanomaterials as carriers, which are characterized by their hydrophobicity, positive potential, biocompatibility, high loading capacities, and large surface areas. Both hematoxylin and eosin endothelial staining and TUNEL assays demonstrate excellent biocompatibility of 6RF@ZIF-8 NF. In in vivo studies, the 6RF@ZIF-8 NF displayed excellent corneal permeation, and outstanding transepithelial CXL (TE-CXL) efficacy, slightly better than the conventional CXL protocol. Furthermore, the special hibiscus-like structures of 6RF@ZIF-8 NF meant that it has better TE-CXL efficacy than that of 6RF@ZIF-8 NP (nanoparticles) due to the larger contact area with the epithelium and the shorter RF release passage. These results suggest that the 6RF@ZIF-8 NF are promising for transepithelial corneal cross-linking, avoiding the need for epithelial debridement.

High-performance self-powered ultraviolet photodetector based on BiOCl/TiO2 heterojunctions: Carrier engineering of TiO2

For low-energy photoelectric devices, it is essential to develop self-powered photodetectors (PDs), because it can work independently, wirelessly and sustainably. The heterojunction PDs based on BiOCl nanoflakes (NFs) and anatase TiO2 film fabricated by the hydrothermal method demonstrate the excellent ultraviolet (UV) photoresponse properties without external power supply. The strong built-in electric field formed at the heterojunction interface and the efficient carrier transmission characteristic of TiO2 film can improve the self-powered performance of PDs. The optimized heterojunction device with TiO2 film grown for 1.75 h exhibits a high photocurrent-to-dark current ratio of 103, responsivity of 0.17 A/W, remarkable detectivity of 1.3 × 1012 Jones, linear dynamic range of 70 dB and fast response speed of 23 ms under 0 V bias and weak UV light irradiation (340 nm, 0.18 mW/cm2). These results demonstrate that the BiOCl/TiO2 heterojunction devices have great application potential in the future UV communications systems.

Efficient Cr(VI) and phosphate removal from contaminated water using MnTiFeO nanoflakes: Statistical modeling and interpretation

MnTiFeO nanoflakes (NF) have been prepared and used to remove Cr(VI) and phosphate from an aqueous solution. The optimum potentials for adsorption of Cr(VI) and phosphate occur at acidic pH and are primarily due to ionic interactions. Langmuir monolayer adsorption is observed. The active sites of NF show some selectivity for Cr(VI) due to various putative interaction modes. The adsorption of Cr(VI) and phosphate are dominated by a multi-docking process, as implied by steric parameters in applied advanced statistical models. The observed selectivity of NF is primarily due to a higher receptor site density for Cr(VI) ions than for phosphate anions. Statistical modeling yields the best fitting of the experimental data for a double-layer in the binary system. MnTiFeO NF can be regarded an effective, competitive, and low-cost adsorbent for the removal of hexavalent Cr and phosphate. The maximum adsorption capacities of MnTiFeO NF for Cr(VI) and phosphate adsorption were evaluated as 166.66 and 163.93 mg/g, respectively.