FlatChem最新文献

The method of monitoring food temperature during food storage needs to be improved to continuously and accurately perceive the temperature of the food in the package to ensure the quality and safety of the food during storage. This paper proposes and develops a battery-free flexible wireless temperature sensing system (BFTS) for food storage. The BFTS consists of a battery-free flexible wireless temperature sensing tag (BFTT), a wireless reader, and a personal computer (PC). The BFTT developed in this paper has good flexibility and can be placed inside the food package to realize the continuous monitoring of temperature changes. The flexible circuits of the BFTT were fabricated by laser engraving laser-induced graphene (LIG) −copper (Cu) plating film made with Cu plating on LIG. The LIG-Cu plating film has good thickness uniformity, electrical conductivity, and laser engraving processability. The antenna of BFTT has good performance. The wireless reader is connected to the PC using a data line, and the BFTT communicates wirelessly with the wireless reader using ultra-high frequency (UHF) radio frequency identification (RFID). The BFTT was realized by the wireless radio frequency (RF) as the supply power from the wireless reader. The BFTS could realize the temperature monitoring of food stored at 0℃ and −18℃, and it has the advantages of low cost, simple manufacturing process, and low energy consumption, which could be used to continuously and accurately monitor the inside temperature of the food packages. Overall, the LIG-Cu plating film developed in this paper could be used in the fabrication of flexible circuits, and the temperature monitoring inside food packages realized by the BFTS has potential applications in actual food storage.

A better understanding of the microstructure, physicochemical properties, and sensing behavior of an electrode is critical in developing quick, high sensitivity, and robust electrochemical sensors. In this study, a single electrode was fabricated with self-prepared graphene ink through a drop-cast process followed with a subsequent annealing treatment. The graphene ink-based electrodes were characterized through AFM, contact angle, FTIR, impedance spectra, Raman, and SEM to understand annealing treatment effects. The dynamic response of the electrode to humidity, and vapors of ethanol, propanol, or acetone was measured using a four-point probe station in a closed chamber. The annealing treatment increased the conductivity of the electrode and improved its sensing performance by forming more and sharper protrusions on the electrode surface. These unique surface protrusions suggest that the annealed graphene ink-based electrodes hold great potential in developing high-performance electrochemical sensors.

The interplay between catalytic agents and substrates in composite materials is crucial in the hydrogen evolution reaction (HER). However, maximizing the utilization of support carrier architectures and ensuring the uniform nucleation and growth of active nanocrystals are imperative for the enhancement of HER capabilities in composite nanomaterials. Herein, we demonstrate a homogeneous synthesis of oxygen-modified 2H-phase molybdenum diselenide nanocrystals on titanium carbide (denoted as MoSe₂/O@Ti₃C₂T_x) to achieve an enhanced HER performance. The improved performance is ascribed to the organ-like structure of Ti₃C₂T_x, which offers numerous sites for anchoring MoSe₂ nanocrystals, hence preventing their excessive aggregation and achieve uniform growth. Ultrathin MoSe₂ crystals and Ti₃C₂T_x interact to reduce the energy barrier for water molecule dissociation, thus improving the catalytic performance for HER. The MoSe₂/O@Ti₃C₂T_x catalyst exhibits outstanding HER performance under acidic conditions, achieving a Tafel slope of 82 mV dec^-1 and a low overpotential of 121 mV at a current density of 10 mA cm⁻², comparable to the best reported MoSe₂-based nanocomposite catalysts. Durability assessments indicate sustained performance for a minimum duration of 10 h at a current density of 10 mA cm⁻². This work lays the groundwork for the development of next-generation high-performance nanocomposite hydrogen evolution catalysts.

This study examines the electronic structure and potential energy surfaces of migration paths in various types of bilayer graphene. Using periodic boundary conditions, density functional theory (DFT), and the generalized gradient approximation (GGA) exchange–correlation functional, along with the nudged elastic band (NEB) method, to investigate the structural stability and dynamic equilibrium of twisted bilayer graphenes (TBGs) with twist angles of 13.2° and 21.8°. The results suggest that twist angles significantly impact atomic and electronic properties, including moiré patterns, superlattice periods, and interfragment distances, which in turn influence bilayer graphene strongly correlated electronic quantum states. This research elucidates the fundamental mechanisms of superlubricity and mutual migration pathways of graphene fragments in TBGs. The low migration barriers observed could facilitate transitions between different energy-related phases, which are determined by the lattice moiré patterns and the localization character of the electronic states, resulting in superlubricity. External mechanical factors may affect the quantum properties of TBGs, indicating potential applications in quantum computing and quantum sensing.

The uneven surface of planar zinc (Zn) metal anodes fundamentally reduces the electrochemical reversibility of aqueous Zn metal batteries due to dendritic growth. Herein, an interphase protection layer engineering is formed on the surface of the Zn metal anode through a solution-processed coating method. This interesting carbon layer, composed of carbon nanoparticles obtained from outer flame-derived candle soot (OFCS), exhibits excellent Zn ion capturing and storage capabilities, effectively reducing the accumulation of charge density on the Zn metal surface, providing a homogeneous Zn ion flux and inducing even Zn metal deposition. The OFCS@Zn can promote the desolvation of [Zn(H₂O)₆]²⁺ through strong interaction with Zn ions, mitigating corrosion and hydrogen evolution reactions. The multifunctional integration of the OFCS layer synergistically induces uniform Zn metal plating and inhibits side reactions. Consequently, in the OFCS @Zn | OFCS @Zn symmetric-cell tests, high-rate performance and deep charge/discharge capabilities are demonstrated. The OFCS@Zn anode-based pouch cell exhibits a high discharge capacity of 156.2 mAh g^-1 and maintains a significant capacity retention rate of 95.4 % for 200 cycles at the current density of 1 A g^-1, indicating its potential for enhanced battery stability and efficiency.

Miniaturized and stabilized polarization-sensitive mid-Infrared photodetectors at room temperature are indispensable in fields ranging from medical diagnostics to military surveillance in the next-generation on-chip polarimeters. Emerging two-dimensional materials offer a promising avenue to fulfill these requirements, facilitated by their ease of integration onto complex structures, inherent in-plane anisotropic crystal structures that enhance polarization sensitivity, and robust quantum confinement effects that enable superior photodetection performance at room temperature. Here, we report the systematic investigation of polarization-dependent infrared photoresponse based on Ta₂NiSe₅, revealing significant anisotropy photocurrent with excellent stability at room temperature. Significantly, a large anisotropic ratio of Ta₂NiSe₅ ensures the polarization sensitivity achieves a ratio of 1.23 at 1550 nm. Moreover, at 4.6 μm, the device exhibits a peak photocurrent response of 1.16 A/W along the armchair orientation, with an anisotropy ratio of approximately 3.3. These findings not only enhance our understanding of the photophysical mechanisms in two-dimensional materials but also guide the optimization of photodetector design for enhanced performance.

As key components of next-generation battery energy storage systems, solid-state batteries have attracted widespread attention. Li₁₀GeP₂S₁₂ (LGPS)-type solid-state electrolytes (SSEs) are favored by researchers owing to their excellent ionic conductivity and potential high-temperature stability. However, the poor interface between LGPS-type SSEs and electrodes has seriously hindered the commercialization of LGPS all-solid-state lithium batteries. This review introduces the structure and Li-ion conduction mechanisms of LGPS-type SSEs and discusses the challenges related to LGPS-type SSEs/electrode interfaces, along with strategies for overcoming these challenges. To improve the interface compatibility, researchers have developed feasible methods for improving and optimizing LGPS-type SSEs. The review concludes with potential research directions and prospects of future LGPS all-solid-state lithium batteries.

Penta-octa-graphene (POG) consists of pentagonal and octagonal carbon rings, hosting type-I and type-II Dirac line nodes due to its sp² and sp³ mixed bonds. Inorganic analogs of 2D carbon lattices have increased the potential applications and changed the main properties of carbon-based structures. Therefore, this work proposes penta-octa-graphene based on silicon carbide using DFT simulations. With a cohesive energy of −5.22 eV/atom, POG-Si₅C₄ is energetically viable in comparison with other silicon carbide-based monolayers. Phonon dispersion analysis confirms the POG-Si₅C₄ dynamical stability. MD simulations demonstrate that this new monolayer can withstand temperatures up to 1020 K. Electronic analysis indicates it is a semiconductor with an indirect band gap transition of 2.02 eV. The mechanical properties exhibit anisotropy, with Young’s modulus ranging from 38.65 to 99.47 N/m and an unusual negative Poisson’s ratio of −0.09. The band edge alignment suggests that POG-Si₅C₄ holds potential for hydrogen generation through photocatalytic water splitting. This research opens possibilities for designing inorganic penta-octa-based structures and provides insights for future experimental and theoretical studies focused on exploring and optimizing advanced silicon-carbide 2D materials.

MXene’s outstanding performance in driving the Hydrogen Evolution Reaction (HER) has attracted significant interest. The HER involves hydrogen generation by electrolyzing water. It is widely recognized that hydrogen represents a renewable and future-oriented alternative energy source that is currently receiving significant attention. On the other hand, MXenes also have a crucial function as catalysts, elevating the pace and effectiveness of chemical reactions. Moreover, their properties make them essential in diverse fields, contributing to advancements in energy storage, sensing technology, and catalysis for improved reactions. Herein, we highlighted MXene nanocomposite materials from synthesized to utilization in HER reaction both experimentally and theoretically. Various MXene-based nanocomposites, which consist of monomer, carbon, and oxide that can be used in hydrogen evolution reactions, are also elaborated in detail. Ultimately, we concluded this review with the future prospect of MXenes in electrochemical HER.

Metal chalcogenides like Tin sulfide (SnS₂) presents as viable alternative electrocatalysts for alkaline water splitting (AWS) due to their huge abundance, stability, and environment friendly nature. However, insufficient exposed active sites and poor conductivity severely impede its large-scale applications. In this work, an in-situ hybridization of hexagonal SnS₂ with intercalation of reduced graphene oxide nanosheets (TS-rGOx) overcomes the problem of SnS₂ stacking. It further enhances the interlayer spacing thereby boosting the number of active sites. The resulting TS-rGOx exhibited excellent oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) activities demanding low overpotential of 313 mV and 196.2 mV at 20 mA/cm² with long term durability upto 60 h, which can be attributed to enhanced interlayer spacing of SnS₂, abundant active sites and higher conductivity resulting from the in-situ hybridization and intercalation of rGO nanosheets. This work opens a prospect towards the design and application of efficient SnS₂ based heterostructured electrocatalyst for AWS.