Publications by authors named "Xue Feng Cheng"

Article Synopsis
  • The electrochemical reduction of nitrate to ammonia (NORR) presents a more sustainable alternative to traditional ammonia production methods, prompting significant research into efficient electrocatalysts.
  • Molecular electrocatalysts, particularly Cu-based ones, show great potential for NORR but face challenges like complex synthesis, use of harmful solvents, and stability issues.
  • A new, simpler method was developed to create Cu-ATU and Ni-ATU electrocatalysts, with Cu-ATU demonstrating exceptional performance in ammonia production, thus advancing the field and aligning with industrial needs.
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  • - A new 4D hyperchaotic system has been developed from a modified 3D Lorenz system, characterized by a single equilibrium point, and its stability and dynamic properties were thoroughly analyzed using MATLAB simulations.
  • - The system exhibits hyperchaotic behavior across various parameter ranges and transitions through multiple states, and its behavior has been validated with STM32 embedded hardware for accuracy in reproducing chaotic attractors.
  • - The hyperchaotic system is applied to a new image encryption method that passes rigorous security tests and demonstrates effectiveness in various fields like audio/video encryption, IoT security, and medical data protection.
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Organic molecules are of great interest for gas sensing applications. However, achieving high-performance gas sensors with high sensitivity, fast response, low consumption, and workability in humid conditions is still challenging. Herein, we report the rational design and synthesis of an ion-in-conjugation polymer, PADC (poly-4,4'-azodianiline-croconamide), obtained by the condensation of croconic acid with 4-4'diaminoazobenzene for gas sensing under humid conditions.

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Article Synopsis
  • A new 4D hyperchaotic system is developed based on an existing 3D Lü chaotic system, simplifying the structure and providing a sole equilibrium point for better analysis of its dynamic behaviors.
  • The system's dynamics are extensively analyzed, revealing complex characteristics like chaotic attractors and sensitivity to parameter changes, confirmed by numerical results showing non-periodic, fractal motion.
  • To explore practical uses, a linear feedback control strategy stabilizes the system, and audio encryption is successfully implemented using hyperchaotic keys on an STM32 platform, demonstrating the system's real-world applications.
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Electrochemical oxidation of urea is of great importance in the removal and energy exchange and storage of urea from wastewater as well as of potential applications in potable dialysis of end-stage renal disease. However, the lack of economical electrocatalysts hinders its widespread application. In this study, we successfully fabricated ZnCoO nanospheres with bifunctional catalysis on nickel foam (NF).

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As a common toxic gas, nitrogen dioxide (NO) seriously threatens the environment and human respiratory system even at part per billion (ppb) level. Covalent organic frameworks (COFs) have gained widespread attention in sensing applications because of the benefits of designability, environmental stability, and a large number of active sites. However, the competitive adsorption of water molecules and the target gas molecules at room temperature as well as the weak interaction between COFs and gas molecules hinder their practical applications.

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Nitrate electrocatalytic reduction (NO RR) for ammonia production is a promising strategy to close the N-cycle from nitration contamination, as well as an alternative to the Haber-Bosch process with less energy consumption and carbon dioxide release. However, current long-term stability of NO RR catalysts is usually tens of hours, far from the requirements for industrialization. Here, symmetry-broken Cusingle-atom catalysts are designed, and the catalytic activity is retained after operation for more than 2000 h, while an average ammonia production rate of 27.

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Owing to their special photoelectric properties, halide perovskites have always attracted research attention. Hollow-structured halide perovskites have many practical applications but are challenging to prepare as most template methods violate their poor chemical and thermal stability. In this study, novel halide perovskite Cs PdBr hollow nanospheres are prepared using a template-free method; specifically, large quantities of highly pure lead-free halide perovskite Cs PdBr hollow nanospheres are produced at 30 °C without a surfactant.

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Organic electrical gas sensors have been developed for many decades because of their high sensitivity and selectivity. However, their industrialization is severely hindered by their intrinsic humidity susceptibility and poor recovery. Conventional organic sensory materials can only operate at room temperature owing to their weak intermolecular interactions.

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MXenes are a new type of two-dimensional material, and they have attracted extensive attention because of their outstanding conductivity and rich surface functional groups that make surface engineering easy and possible for adapting to diverse applications. However, there are scarce studies on surface engineering of MXene. Herein, we demonstrate for the first time that octylphosphonic acid-modified TiCT MXene can be used as an active layer for memory devices and exhibits stable ternary memory behavior.

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Article Synopsis
  • * This research introduces a lead-free double perovskite material, Cs AgBiBr, for creating durable memristors that maintain their memory capabilities after extensive use and stress testing.
  • * The memristors show exceptional stability under extreme conditions (high humidity, elevated temperatures, flames, and radiation), outperforming traditional memristors and commercial flash memory, paving the way for more resilient electronic devices.
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Conjugated coordination polymers have become an emerging category of redox-active materials. Although recent studies heavily focus on the tailoring of metal centers in the complexes to achieve stable electrochemical performance, the effect on different substitutions of the bridging bonds has rarely been studied. An innovative tailoring strategy is presented toward the enhancement of the capacity storage and the stability of metal-organic conjugated coordination polymers.

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  • * Researchers have developed quaternary memory using hybrid perovskite memcapacitors, achieving four distinct capacitance states with a remarkable yield of nearly 100%.
  • * The switching mechanism is based on changes in p-i-n junction capacitance due to Br migration, which differs from the commonly studied memristive switching, offering a novel approach to efficient information storage.
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Recently, resistance random access memories (RRAMs) have been studied extensively, because the demand for information storage is increasing. However, it remains challenging to obtain a flexible device because the active materials involved need to be nontoxic, nonpolluting, distortion-tolerable, and biodegradable as well adhesive to diverse flexible substrates. In this paper, tannic acid (TA) and an iron ion (Fe ) coordination complex were employed as the active layer in a sandwich-like (Al/active layer/substrate) device to achieve memory performance.

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Nitrogen dioxide (NO ) emission has severe impact on human health and the ecological environment and effective monitoring of NO requires the detection limit (limit of detection) of several parts-per-billion (ppb). All organic semiconductor-based NO sensors fail to reach such a level. In this work, using an ion-in-conjugation inspired-polymer (poly(3,3'-diaminobenzidine-squarine, noted as PDBS) as the sensory material, NO can be detected as low as 1 ppb, which is the lowest among all reported organic NO sensors.

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Objective: To investigate the species and activities of wild animals infected with schistosome in hilly and mountain areas by using an infrared camera technique, so as to provide the evidence for the surveillance of schistosomiasis in these areas.

Methods: Six infrared cameras were selected and placed in 6 environments of the risk monitoring points of schistosomiasis in Shitai County in Anhui Province. The species and activities of the wild animals in the 6 environments were observed through the photographs and videos taken by the cameras.

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In recent years, numerous organic molecules and polymers carrying various functional groups were synthesized and used in fabrication of wearable electronic devices. Compared to previous materials that suffer from poisonousness, stiffness and complex film fabrication, we circumvent above matters by taking advantage of mussel-inspired polydopamine as our active material to realize resistive random access memories (RRAMs). Polydopamine thin films were grown on indium tin oxide glass catalyzed by Cu SO /H O and characterized by Fourier infrared spectroscopy (FT-IR), UV/Vis spectroscopy and scanning electron microscopy.

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Recently, organic-inorganic hybrid perovskites (OIHP) are studied in memory devices, but ternary resistive memory with three states based on OIHP is not achieved yet. In this work, ternary resistive memory based on hybrid perovskite is achieved with a high device yield (75%), much higher than most organic ternary resistive memories. The pseudohalide-induced 2D (CH NH ) PbI (SCN) perovskite thin film is prepared by using a one-step solution method and fabricated into Al/perovskite film/indium-tin oxide (glass substrate as well as flexible polyethylene terephthalate substrate) random resistive access memory (RRAM) devices.

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Recently, surface engineering of the indium tin oxide (ITO) electrode of sandwich-like organic electric memory devices was found to effectively improve their memory performances. However, there are few methods to modify the ITO substrates. In this paper, we have successfully prepared alkyltrichlorosilane self-assembled monolayers (SAMs) on ITO substrates, and resistive random access memory devices are fabricated on these surfaces.

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Herein, for the first time, quaternary resistive memory based on an organic molecule is achieved via surface engineering. A layer of poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) (PEDOT-PSS) was inserted between the indium tin oxide (ITO) electrode and the organic layer (squaraine, SA-Bu) to form an ITO/PEDOT-PSS/SA-Bu/Al architecture. The modified resistive random-access memory (RRAM) devices achieve quaternary memory switching with the highest yield (∼41%) to date.

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Organic multilevel random resistive access memory (RRAM) devices with an electrode/organic layer/electrode sandwich-like structure suffer from poor reproducibility, such as low effective ternary device yields and a wide threshold voltage distribution, and improvements through organic material renovation are rather limited. In contrast, engineering of the electrode surfaces rather than molecule design has been demonstrated to boost the performance of organic electronics effectively. Herein, we introduce surface engineering into organic multilevel RRAMs to enhance their ternary memory performance.

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Squaraine molecules deposited on indium tin oxide (ITO) substrates modified with phosphonic acids crystalize more orderly than do those on untreated ITO. The as-fabricated electro-resistive memories show the highest ternary device yield observed to date (82%), a narrower switching voltage distribution, and better retention as well as resistance uniformity.

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Herein, two molecules based on urea and thiourea, which differ by only a single atom, were designed, successfully synthesized, and fabricated into resistive random-access memory devices (RRAM). The urea-based molecule showed binary write-once-read-many (WORM) storage behavior, whereas the thiourea-based molecule demonstrated ternary storage behavior. Atomic-force microscopy (AFM) and X-ray diffraction (XRD) patterns show that both molecules have smooth morphology and ordered layer-by-layer lamellar packing, which is beneficial for charge transportation and, consequently, device performance.

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An organic thin-film gas sensor based on squaraine detects ammonia as low as 40 ppb with impressive reversibility and stability. The resonance-stabilized zwitterionic characteristics offer squaraines high affinity and sensitivity toward electron-rich analytes without irreversible chemical binding, while the embedded squaric ring makes SA-CH highly sensitive. The symmetric molecular geometry and good crystallinity also contribute to the high performance.

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To optimize the fertilization rate of winter wheat under drip irrigation in Xinjiang region, a field investigation was carried out to assess effects of nitrogen (N) applications on canopy vertical structure, grain-leaf ratio, yield and economic benefit of winter wheat. Four rates of nitrogen application, 0 kg·hm(N), 104 kg·hm(N), 173 kg·hm(N) and 242 kg·hm(N) were set in a randomized block experimental design. Meantime, leaf and stem morphological characters, canopy temperature and humidity in flowering stage, grain-leaf area ratio, yield and yield components, economic benefits of winter wheat were observed under different treatments.

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