A Functionally Asymmetric Janus Hygro-Photothermal Hybrid for Atmospheric Water Harvesting in Arid Regions.

Metal-organic frameworks (MOFs) are high-performance adsorbents for atmospheric water harvesting but have poor water-desorption ability, requiring excess energy input to release the trapped water. Addressing this issue, a Janus-structured adsorbent with functional asymmetry is presented. The material exhibits contrasting functionalities on either face - a hygroscopic face interfaced with a photothermal face. Hygroscopic aluminum fumarate MOF and photothermal CuxS layers are in-situ grown on opposite sides of a Cu/Al bimetallic substrate, resulting in a CuxS-Cu/Al-MOF Janus hygro-photothermal hybrid. The two faces serve as independent "factories" for photothermal conversion and water adsorption-desorption respectively, while the interfacing bimetallic layer serves as a "heat conveyor belt" between them. Due to the high porosity and hydrophilicity of the MOF, the hybrid exhibits a water-adsorption capacity of 0.161 g g-1 and a fast adsorption rate (saturation within 52 min) at 30% relative humidity. Thanks to the photothermal CuxS, the hybrid can reach 71.5 °C under 1 Sun in 20 min and desorb 97% adsorbed water in 40 min, exhibiting a high photothermal conversion efficiency of over 90%. CuxS-Cu/Al-MOF exhibits minimal fluctuations after 200 cycles, and its water-generation capacity is 3.21 times that of powdery MOF in 3 h in a self-designed prototype in one cycle.

Functional MXenes: Progress and Perspectives on Synthetic Strategies and Structure-Property Interplay for Next-Generation Technologies.

MXenes are a class of 2D materials that include layered transition metal carbides, nitrides, and carbonitrides. Since their inception in 2011, they have garnered significant attention due to their diverse compositions, unique structures, and extraordinary properties, such as high specific surface areas and excellent electrical conductivity. This versatility has opened up immense potential in various fields, catalyzing a surge in MXene research and leading to note worthy advancements. This review offers an in-depth overview of the evolution of MXenes over the past 5 years, with an emphasis on synthetic strategies, structure-property relationships, and technological prospects. A classification scheme for MXene structures based on entropy is presented and an updated summary of the elemental constituents of the MXene family is provided, as documented in recent literature. Delving into the microscopic structure and synthesis routes, the intricate structure-property relationships are explored at the nano/micro level that dictate the macroscopic applications of MXenes. Through an extensive review of the latest representative works, the utilization of MXenes in energy, environmental, electronic, and biomedical fields is showcased, offering a glimpse into the current technological bottlenecks, such asstability, scalability, and device integration. Moreover, potential pathways for advancing MXenes toward next-generation technologies are highlighted.

In-situ formation of niobium oxide - Niobium carbide - Reduced graphene oxide ternary nanocomposite as an electrochemical sensor for sensitive detection of anticancer drug methotrexate.

Engineering the nanostructure of an electrocatalyst is crucial in developing a high-performance electrochemical sensor. This work exhibits the hydrothermal followed by annealing synthesis of niobium oxide/niobium carbide/reduced graphene oxide (NbO/NbC/rGO) ternary nanocomposite. The oval-shaped NbO/NbC nanoparticles cover the surface of rGO evenly, and the rGO nanosheets are interlinked to produce a micro-flower-like architecture. The NbO/NbC/rGO nanocomposite-modified electrode is presented here for the first time for the rapid and sensitive electrochemical detection of the anticancer drug methotrexate (MTX). Down-sized NbO/NbC nanoparticles and rGO's high surface area provide many active sites with a rapid electron transfer rate, making them ideal for MTX detection. In comparison to previously reported MTX sensors, the developed drug sensor exhibits a lower oxidation potential and a higher peak current responsiveness. The constructed sensors worked analytically well under optimal conditions, as shown by a low detection limit of 1.6 nM, a broad linear range of 0.1-850 µM, and significant recovery findings (∼98 %, (n = 3)) in real samples analysis. Thus, NbO/NbC/rGO nanocomposite material for high-performance electrochemical applications seems promising.

Hexagonal nanosheets of pyrrochlore-type lanthanum stannate for sensitive detection of chlorinated pesticide in food and environmental samples.

2,4,6-Trichlorophenol (TCP) is the most widely used pesticide in the world and has a devastating effect on the environment and human health. As a result of the use of pyrochlore type La2Sn2O7 hexagonal nanosheet (La2Sn2O7 HNS) modified electrode, this work reports on the quick and sensitive electrochemical detection of TCP. The La2Sn2O7 HNS is reported here for the first time and has been made using a simple precipitation and calcination technique. The crystal structure and surface morphologies of La2Sn2O7 HNS have been characterized using XRD, XPS, HR-TEM, and FE-SEM analyses. Detection limits of 0.074 µM and sensitivity of 1.5 µA µM-1 cm-2 were achieved using the La2Sn2O7 HNS for TCP detection. It also showed decent selectivity among the common interfering molecules. Additionally, the La2Sn2O7 HNS/GCE sensor was able to detect TCP in water and vegetable samples with >90 % recovery, proving its appropriateness for quick TCP detection.

Tailored architecture of molybdenum carbide/iron oxide micro flowers with graphitic carbon nitride: An electrochemical platform for nano-level detection of organophosphate pesticide in food samples.

Herein we report the ternary hybrid nanocomposite of iron oxide @ molybdenum carbide micro flowers decorated graphitic-carbon nitride (Fe3O4@MoC MFs/g-CN), as a catalyst for the detection of organophosphorus pesticide, parathion (PAT), for the first time. The growth of hierarchical nanostructure from the core level will facilitate easy diffusion of analyte and interact more effectively with the reactive catalytic sites. Thus, Fe3O4 NFs architecture was hydrothermally grown over MoC flakes from the core level, which further hybridized with g-CN to ensure electrical conductivity and mechanical stability. Experimental results demonstrate that Fe3O4@MoC MFs/g-CN/GCE has superior catalytic efficacy for PAT reduction. At optimum conditions, the proposed sensor exhibits a low detection limit (7.8 nM), high sensitivity, and wide linear range (0.5-600 µM) toward PAT detection. The satisfactory test results of the food samples indicate that the Fe3O4@MoC MFs/g-CN/GCE sensor can be used as an excellent candidate for real-time PAT detection.

3D-flower-like porous neodymium molybdate nanostructure for trace level detection of organophosphorus pesticide in food samples.

Herein we report (i) designing of porous 3D flower-like neodymium molybdate nanosheets (pf-NdM NSs) and (ii) attaining reasonable selectivity towards methyl parathion (MP, organophosphate pesticide) in the presence of structurally comparable interferents. Herein the pf-NdM NSs as a catalyst for electrochemical detection of MP in food samples is reported for the first time. Because of porous morphology, and high surface area, the proposed catalyst offers a high electrocatalytic activity toward MP reduction. As a result, a low detection limit (5.7 nM), wide linear range (0.5 - 300 µM), and good sensitivity (1.88 µA µM-1 cm-2), with decent selectivity were achieved. Further, the real sample analysis in tomato juice, and paddy grains, yielded good recovery results, demonstrating the practicability of the proposed sensor. Overall, our study presents a method for designing a novel-nanostructured material for trace-level detection of pesticides that is simple to fabricate, and also delivers a good performance.

The feasibility of an approximate irregular field dose distribution simulation program applied to a respiratory motion compensation system.

PURPOSE: This study optimized our previously proposed simulation program for the approximate irregular field dose distribution (SPAD) and applied it to a respiratory motion compensation system (RMCS) and respiratory motion simulation system (RMSS). The main purpose was to rapidly analyze the two-dimensional dose distribution and evaluate the compensation effect of the RMCS during radiotherapy. METHODS: This study modified the SPAD to improve the rapid analysis of the dose distribution. In the experimental setup, four different respiratory signal patterns were input to the RMSS for actuation, and an ultrasound image tracking algorithm was used to capture the real-time respiratory displacement, which was input to the RMCS for actuation. A linear accelerator simultaneously irradiated the EBT3 film. The gamma passing rate was used to verify the dose similarity between the EBT3 film and the SPAD, and conformity index (CI) and compensation rate (CR) were used to quantify the compensation effect. RESULTS: The Gamma passing rates were 70.48-81.39% (2%/2mm) and 88.23-96.23% (5%/3mm) for various collimator opening patterns. However, the passing rates of the SPAD and EBT3 film ranged from 61.85% to 99.85% at each treatment time point. Under the four different respiratory signal patterns, CR ranged between 21% and 75%. After compensation, the CI for 85%, 90%, and 95% isodose constraints were 0.78, 0.57, and 0.12, respectively. CONCLUSIONS: This study has demonstrated that the dose change during each stage of the treatment process can be analyzed rapidly using the improved SPAD. After compensation, applying the RMCS can reduce the treatment errors caused by respiratory movements.

Influence of ultrasonic combined supercritical-CO2 electrodeposition process on copper film fabrication: Electrochemical evaluation.

Introducing ultrasound irradiation to the electrodeposition process can significantly improve the physical and chemical properties of deposited films. Meanwhile, the beneficial effects from supercritical-CO2, such as high diffusivity, high permeability, low surface tension, etc., would improve the electrodeposition process with better surface quality. In the shed of the light, the present work deals with the preparation of copper (Cu) films using the integrated techniques, i.e., ultrasonic-assisted supercritical-CO2 (US-SC-CO2) electrodeposition approach. For comparison, Cu films were also prepared by normal supercritical-CO2 (SC-CO2) and conventional electrodeposition methods. To investigate the characteristics of Cu films, surface morphology analysis, roughness analysis, X-ray diffraction studies (XRD), Linear polarization, electrochemical impedance spectroscopy (EIS), and cyclic voltammetry (CV) were performed. In this work, EIS analysis was utilized for interfacial charge transfer resistance analysis with 5 mM [Fe(CN)6]-3/-4 redox system and corrosion analysis with 3.5 wt% NaCl solution. The observed results revealed that the film prepared with the US-SC-CO2 method have superior properties than those produced by normal SC-CO2 and conventional methods. Due to the combination of US-SC-CO2, the cavitation implosion occurs rapidly that enriches the deposited film quality, such as sufficient grain size, smoother surface, enhanced corrosion resistance, and charge carrier dynamics. On the other hand, the ultrasound effect with SC-CO2 helped to remove the weakly adhered metal ions on the electrode's surface.

Ultrasonic-assisted supercritical-CO2 electrodeposition of Zn-Co film for high-performance corrosion inhibition: A greener approach.

The ultrasonic-assisted electrodeposition process significantly improves the mechanical and electrochemical properties. Meanwhile, supercritical fluid technology also enhances the electrodeposition process with increased benefits, such as low surface tension, permeability, high diffusivity, and density, which improves the surface quality through grain refinement. In this study, Zn-Co films were prepared using the ultrasonic-assisted supercritical-CO2 (US-SC-CO2) electrodeposition approach, and its pressure effect on the film was evaluated. The films were also prepared by the conventional and typical supercritical-CO2 (SC-CO2) methods for a comparison study. All the prepared films were characterized by morphological studies, elemental composition, crystal structure orientation, and microhardness tests. Later, the fabricated films were examined by potentiodynamic polarization technique and electrochemical impedance technique (EIS) with 3.5 wt.% NaCl solution for corrosion evaluation. Based on results, Zn-Co film prepared through the US-SC-CO2 process shows a spherical nodule like structure with reduced grain size and significantly enhanced hardness property. In XRD studies, the shift in diffracted peak's position reveals the increased proportion of Co ions. Further, EDX results also confirm the same with the characteristic peaks. Finally, compared to the other methods, the corrosion resistance was more efficient in the US-SC-CO2 process by 73.75%.