FlatChem最新文献

This research explores the efficacy of photodynamic therapy (PDT) and photothermal therapy (PTT) in combating chemotherapy-resistant diseases. This study focuses on enhancing tumor treatment effectiveness by leveraging the synergetic effects of combining PDT and PTT through the development of Fe-nitrogen-carbon (FeNC) nanoparticles with superior photostability. These nanoparticles, functioning as photosensitizers for the combined PDT/PTT treatment, can generate both type I and type II ROS and heat upon 808 nm irradiation. Notably, the FeNC nanoparticles demonstrate an exceptional photothermal conversion efficiency (34 %), surpassing commonly used PTT photosensitizers. In vitro and in vivo experiments corroborate the efficiency of FeNC as a photosensitizer in achieving significant tumor inhibition. In conclusion, the FeNC nanoparticles present promising applicability in the synergistic PTT/PDT treatment of tumors.

Pt-functionalized graphene shows promise for near-ambient hydrogen storage due to graphene’s potential as a hydrogen host and platinum’s role as a catalyst for the hydrogen evolution reaction and spillover effect. This study explores Pt cluster formation on epitaxial graphene and its suitability for hydrogen storage. Scanning Tunneling Microscopy reveals two growth pathways. Initially, up to $\sim$1 monolayer of Pt coverage, Pt tends to randomly disperse and cover the graphene surface, whereas the cluster height remains unchanged. Beyond a coverage of 3 monolayer, the nucleation of new layers on existing clusters becomes predominant, and the clusters mainly grow in height. Thermal Desorption Spectroscopy on hydrogenated Pt-decorated graphene reveals the presence of multiple hydrogen adsorption mechanisms. Two Gaussian peaks, which we attribute to hydrogen physisorbed (peak at 155°C) and chemisorbed (peak at 430°C) on the surface of Pt clusters are superimoposed on a linearly increasing background assigned to hydrogen bonded in the bulk of the Pt clusters. These measurements demonstrate the ability of Pt-functionalized graphene to store molecular hydrogen at temperatures that are high enough for stable hydrogen binding at room temperature.

Developing highly active, low-cost, and robust transition metal-based phosphide for alkaline overall water splitting is of utmost important to promote the practical application from fundamental. Herein, two-dimensional (2D) Mo-doped NiCoP nanoplates with novel amorphous/crystalline heterostructure (Mo(0.05)-NiCoP) in situ grown on three-dimensional nickel foam (NF) has been successfully constructed through hydrothermal reaction followed by the phosphorization treatment. Benefited from the synergy of amorphous/crystalline heterointerface, Mo doping, and unique 2D structure, the optimized Mo(0.05)-NiCoP exhibits outstanding electrocatalytic activity for hydrogen evolution reaction (HER) and oxygen evolution reaction (OER), achieving low overpotential of 67 mV at 10 mA cm⁻² for HER and 233 mV at 10 mA cm⁻² for OER. Meanwhile, there are only a cell voltage of 1.569 V was required to drive 10 mA cm⁻² when Mo(0.05)-NiCoP used as both anode and cathode for overall water splitting. Thus, this study provides a novel approach to construct efficient 2D bifunctional catalysts with amorphous/crystalline heterostructure and heterogeneous metal doping.

The hexagonal Boron Nitride (hBN) nanostructures with tuned physicochemical properties find huge applications in optoelectronic devices. Herein, we have synthesized nanocomposite of hBN with graphene oxide (GO) in various ratios to acquire composition-dependent variation in their structural, surface electronic, linear, and non-linear optical properties. The insertion of GO in hBN nanosheets has modified their strain landscape, the electronic charge transfers from GO to hBN, increased the working time of free charge carriers, and suppressed electron-hole recombination, thus modifying its work function (WF). GO-hBN nanocomposites observed to have reduced bandgap where creation of defect induced mid-gap states lead to enhancement in non-linear absorption of two photons. Herein, we have established a linear relationship between Urbach energy (E_u), a measure of disorders and non-linear absorption coefficient (α_NL). Additionally, we have observed that the tuned bandgap of the nanocomposites has significantly enhanced their performance as high-performance photocatalysts for the degradation of methyl orange, compared to bare hBN or GO. As a result, we discovered that E_u, α_NL, WF and photodegradation activity of GO-hBN nanocomposites exhibit analogous variations in response to changes in the content of GO. Thus, by strategically prioritizing the modification of a single parameter while considering the potential effects on other relevant properties for application purpose, GO-hBN can effectively harness large spectrum areas for catalytic and optoelectronic applications.

Highly determined materials have been applied to energy storage devices such as supercapacitors, batteries, etc., to investigate their electrochemical features and match them with ongoing technological developments. In this regard, electrodes based on graphene and layered double hydroxide with two divergent charge-storage mechanisms have been perused to expand the energy storage functionalities. Graphene materials as efficient electrodes have occupied a significant place in supercapacitors and batteries due to their outstanding electrical conductivity, flexibility, and large surface area. Additionally, according to the substantial electrochemical charge transport capabilities, layered double hydroxides are extensively employed in energy storage devices. This review comprehensively investigates the cooperation effect of the electrode composites of the graphene materials and layered double hydroxides and their optimization progress. The electrochemical characteristics of the electrodes have been considered, including specific capacitance, energy density, power density, and capacity retention, affected by pH, synthesis method, reaction temperature, and time. Eventually, the future trend of the electrode materials and their enhancing performance perspective is represented.

Graphene research has captivated researchers worldwide, propelling innovation across diverse industries. Through the liquid-phase exfoliation methodology of graphite powder, we have demonstrated a rapid route for obtaining few-layer and multi-layer graphene using a natural surfactant, cardanol. Aqueous phase exfoliation of graphite in the presence of cardanol as a surfactant was conducted to obtain pre-exfoliated graphite suspensions. The influence of different ultrasonication times, 10, 20, and 30 min, and contact times with the surfactant, 1 and 60 min, on the stability and concentration of dispersed exfoliated graphite was evaluated. Results indicate that ultrasonication for 20 min resulted in improved stability and reduced graphene flake sizes, making it suitable for scalable graphene production. Subsequently, the most stable dispersions of exfoliated graphite were subjected to CO₂-pressurized treatment. Promising results were obtained when employing cardanol at its critical micelle concentration. The graphene exhibited good structural quality, low defect density, and small stacking, with an average size of 15 nm, where 40 % of the stacked graphene was smaller than 5 nm. The findings provide valuable recommendations for the scalable production of graphene with multilayers and a few layers (FLG/MLG), using cardanol, a friendly surfactant, and a novel method of exfoliation utilizing supercritical CO₂. This technology represents an innovative approach, with potential applications in supercapacitors, solar cells, biosensors, polymer composites, and advanced materials.

The doping of lighter non-metals like boron and nitrogen into fullerene $\left(C_{60}\right)$ represents a promising advancement in the field of nanoelectronic devices. These doped two-dimensional (2D) materials offer improved stability and enhanced adsorption characteristics compared to pure form. Notably, It displays semiconducting behaviour, resulting in higher conductivity and carrier mobility. This study investigates the structural, electronic, optical, and conductivity/carrier transport properties of 2D polymer sheets made of fullerene, both with and without boron and nitrogen doping. We employ density functional theory (DFT) with PBE and HSE functionals, considering the inclusion of van der Waals (vdW) interactions. The research findings indicate that the $2D$ sheets of $C_{60},C_{58}{B}_1{N}_1$, and $C_{54}{B}_3{N}_3$ exhibit band gaps of approximately $0.97eV\left(1.51eV\right),1.08eV\left(1.65eV\right)$, and $1.05eV\left(1.56eV\right)$, respectively, as obtained from PBE (HSE) calculations. Moreover, according to the deformation potential theory, $C_{58}{B}_1{N}_1$ exhibit ultra-high conductivity (${10}^{14}{\Omega }^{-1}{cm}^{-1}{s}^{-1}$ at room temperature). These sheets display cohesive energies of −8.76, −8.72, and $-8.67eV$, respectively, indicating their stability. These results are promising and underscore the significance of a single pair of $BN$ dopants in fullerene monolayers for advancing next-generation 2D nano-electronic applications.

The preservation of Silicon nanoparticles (Si NPs)’ structural integrity and surface protection during cycling is vital for optimal Si-graphene electrodes, controlling volumetric changes during lithiation/delithiation. Weak physical adherence of Si NPs to the carbon matrix compromises electrode performance, highlighting the need for effective bonding mechanisms. This research focuses on Si/reduced graphene oxide (Si/RGO) composites, employing a scalable, low-temperature synthesis method to examine effect of bonding between Si NPs and RGO in mitigating the volumetric fluctuations during cycling. Characterization techniques, including FTIR, XRD, Raman spectroscopy, SEM, EDX and TGA confirm successful synthesis, offering structural and chemical insights. Electrochemical assessments, including EIS, CV, and GCD, reveal that covalently coupled Si/RGO composites outperform counterparts, demonstrating superior rate and cyclic performance. The first delithiation capacity of 1275 mAh g⁻¹ surpasses directly assembled Si/RGO and pristine RGO-based anodes, with corresponding values of 736 and 511 mAh g⁻¹, respectively and is retained to 670 mAh g⁻¹ (1.8 times the capacity compared to a graphite anode) at 0.1 A g⁻¹ after 100 cycles. Furthermore, the research challenges the notion that a high reduction temperature is obligatory for achieving high conductivity in RGO, as observed through improved charge/electron transfer kinetics, detailed in subsequent sections.

2D materials, such as transition metal dichalcogenides (TMDCs), have garnered considerable attention in recent years due to their unique properties and wide-ranging potential applications. Among them, molybdenum disulfide ($\mathrm{Mo}{S}_2$) stands out for its remarkable electronic, optical, and mechanical characteristics. This study aims to optimize the synthesis of liquid-phase exfoliated $\mathrm{Mo}{S}_2$ using ultrasound, focusing on absorbance in the UV–Vis spectrum and the increase in the direct bandgap. The variables studied in this research include ultrasound power and time, as well as the mass of $\mathrm{Mo}{S}_2$, while the response variables involve the area under the curve (absorbance) of excitonic transitions A–D from UV–Vis spectra and the direct bandgap values of $\mathrm{Mo}{S}_2$ A–D excitons obtained through Tauc-Mott models. To predict the optical properties of exfoliated $\mathrm{Mo}{S}_2$, we developed Artificial Neural Network (ANN) algorithms, which were subsequently optimized using a Genetic Algorithm (GA). The performance of the ANN models was assessed using Root Mean Square Error (RMSE) and Standard Error of Prediction (SEP). The results demonstrate that the combined GA-ANN model serves as a valuable tool for predicting the optical properties of exfoliated $\mathrm{Mo}{S}_2$ nanosheets under various experimental conditions. The selected treatments from the optimization process were further characterized using Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), X-ray diffraction (XRD), and Raman spectroscopy, providing additional insights into and correlating with the optical properties. Characterizations through TEM and SEM confirmed the effectiveness of ultrasonic exfoliation in reducing the size of $\mathrm{Mo}{S}_2$ particles and generating smaller particles with varied shapes, including thin flakes. The XRD and Raman spectroscopy analyses revealed changes in the crystalline structure, particle size distribution, and molecular composition of exfoliated $\mathrm{Mo}{S}_2$ selected samples.

Zearalenone, a major mycotoxin encountered in numerous agricultural products, is associated with an array of adverse health implications, notably endocrine disturbances and carcinogenic tendencies. Given the global challenge posed by this toxin, an innovative electrochemical biosensor was crafted using hydrothermally synthesized Bi₂S₃ nanorods. Integrating these nanorods with Carbon Nanofibers (CNF) through a meticulous ultrasonication technique resulted in a high-performance sensing interface optimized for zearalenone detection in intricate agricultural settings. Advanced characterization techniques, encompassing X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), and energy-dispersive X-ray spectroscopy (EDX), corroborated the fine-tuned integration of Bi₂S₃ within the porous CNF matrix. This Bi₂S₃@CNF nanocomposite not only showcased superior electrochemical attributes, but its broad linear detection range and low detection threshold underscore its aptitude for real-world applications. In light of these findings, the Bi₂S₃@CNF nanocomposite stands poised as a pivotal tool in revolutionizing zearalenone detection methodologies, emphasizing the critical role of nanotechnology in addressing contemporary analytical challenges.