FlatChem最新文献

Aerogels, as extraordinarily lightweight and porous functional nanomaterials, have garnered significant interest in both academia and industry over the past few decades. Graphene-based aerogels, in particular, stand out due to their excellent conductivity properties, high specific surface area, and efficient adsorption efficiency. Despite these advantageous properties, aerogels face challenges in mechanical durability, complicating their processing, especially in applications requiring complex structures. 3D printing technology holds promise for overcoming these limitations through its capabilities in microscale manufacturing, rapid prototyping, and arbitrary shaping. This review summarizes the advantages of graphene-based aerogels and compares various 3D printing techniques used for aerogel fabrication. Furthermore, it also highlights the energy and environmental applications of 3D-printed graphene and graphene-based composite aerogels, including batteries, supercapacitors, electromagnetic shielding, sensors, etc. The review concludes with an exploration of current challenges and provides an outlook on future developments in the 3D printing of graphene-based aerogels.

A straightforward and precise method was employed to generate Ti₃C₂ MXene/ZnO/CdSe photocatalysts by a simple synthesis process involving calcination at a temperature of 400 °C. Optical, structural, morphology, microstructure, and compositional properties of these catalysts were characterized. Results demonstrated that the presence of ZnO and CdSe doping sustained their existence inside the Ti₃C₂ MXene structure. Effects of catalyst powder, pollutant powder, and different degrading methods such as sonophotocatalytic, sonocatalytic, and photocatalytic methods on various antibiotic pollutants were then compared. The degradation efficiencies of sonophotocatalytic method were found to be highly efficient, resulting of 99.99, 99.98, and 99.90 % for ciprofloxacin, amoxicillin, and ofloxacin, respectively. Analysis of scavenger effect also illustrated the deterioration of ciprofloxacin and amoxicillin, suggesting that superoxide radicals (O₂⁻) had a substantial role in the sonophotocatalytic degradation process. Based on data obtained for ofloxacin, it was clear that the existence of holes (h⁺ quencher) affected the deterioration of ofloxacin in the system. Ti₃C₂ MXene/ZnO/CdSe had a performance in electrochemical sensing. Limits of detection (LODs) for ciprofloxacin, amoxicillin, and ofloxacin were 39.29, 4.49, and 13.04 ppm, respectively. Limits of quantification (LOQs) for ciprofloxacin, amoxicillin, and ofloxacin were 119, 13.61, and 39.52 ppm, respectively. Efficient degradation of pollutants using visible light can be achieved by employing straightforwardly manufactured Ti₃C₂ MXene/ZnO/CdSe photocatalysts, making them a practical and promising option.

Using Density Functional Theory, a newly synthesised 2-dimensional polyaramid (2dpa) system decorated with Li is explored for its hydrogen storage capability, and interesting results are obtained. Various sites on 2dpa are studied to ascertain the finest location for Li-decoration. The optimum configuration for hydrogen storage is then achieved by successively adding H₂ molecules, till it satisfies the adsorption energy window as prescribed by DoE (0.2–0.7 eV/H₂). Li has a good binding energy of −2.78 eV on 2dpa, higher than the cohesive energy for Li and thus prevents any possibilities of clustering. Yet the clustering has been checked by calculating the diffusion energy barrier for the Li atom which came to be around 1.92 eV. The average binding energy for H₂ on 2dpa + Li came to be −0.25 eV and the gravimetric weight percent with 3Li on 2dpa and 6H₂ molecules attached to each Li comes to be 10.62. Both values meet the conditions set by the US DoE for solid-state hydrogen storage systems. The thermal and dynamic stability of the system has been investigated using Ab initio Molecular Dynamics simulations and computing phonon spectra. Our theoretical results on newly synthesized 2D material may inspire the experimentalist to design a 2dpa-based high-capacity hydrogen storage device.

MXenes represent a revolutionary class of two-dimensional (2D) materials that have garnered significant attention due to their unique properties, including excellent electrical conductivity, and remarkable mechanical strength. This study investigates the influence of different etching agents on the synthesis of MXenes for electrochemical energy conversion applications, particularly in methanol oxidation reactions (MOR). Morphological characterization, particle distribution and sizing, elemental analysis, and surface chemistry assessments were conducted using field emission scanning electron microscopy (FESEM), elemental mapping, transmission electron microscopy (TEM), x-ray diffraction (XRD), and x-ray photoelectron spectroscopy (XPS). Electrochemical techniques such as cyclic voltammetry (CV), electrochemical active surface area (ECSA), Tafel analysis, electrochemical impedance spectroscopy (EIS), and long-term stability assessment were employed. The study reveals that PtRu/MXene synthesized with the FeF₃/HCl etching route exhibits the highest ECSA value and peak current density, being 12.3 times and 3.63 times higher than those achieved via the LiF/HCl etching route. The kinetic rate, tolerance to catalyst poisoning and long-term stability also show the better results for this etching route. These findings suggest promising potential for PtRu/MXene_FeF₃/HCl as an effective anodic electrocatalyst in direct methanol fuel cell (DMFC) applications.

We constructed SiC/borophene heterostructure based on the method of commensurate lattice with supercell approach and studied the structural, electronic and electrochemical properties using density functional theory (DFT). The interfacial binding energy of SiC/borophene is as high as −26.07 meV/Ų. Significant amounts of charge were found to drift from SiC to borophene, resulting in interfacial charge redistribution and increased Li binding affinity on the surfaces. The electronic properties of SiC/borophene showed pronounced metallic conductivity, a trait conducive to anodic applications in electrochemical cells. The calculated Li adsorption energy at the interface of SiC/borophene is −2.23 eV. Multiple layer adsorption is also observed, with the heterostructure retaining much of its structural integrity after adatom adsorption, indicating possible good cycling stability. At the maximum concentration, the Li storage capacity for SiC/borophene is 1980.63 mAh/g, surpassing a large variety of other reported 2D complexes. Also, an overall average operating voltage of 1.06 V is maintained in the structure, which is in proximity of the optimal 1.5 V threshold requisite for anodic operations. The diffusion energy barriers associated with lithium ion migration across the three distinct adsorption sites of the heterostructure all reveal a nominal magnitude with the lowest barrier energy of 0.54 eV at the top of borophene adsorption layer and site. These findings show that SiC/borophene could be used as an anode in very high-capacity lithium-ion batteries.

The 2-electron electrocatalytic oxygen reduction reaction (2e⁻ ORR) to hydrogen peroxide (H₂O₂) represents a promising strategy to resolve the high energy consumption and increasing environmental concerns inherent in the traditional anthraquinone process. The acidic 2e⁻ ORR has emerged as an exciting alternative for industrial-level H₂O₂ production, whereas is hampered by the inferior H₂O₂ selectivity due to the uncontrollable proton-coupled electron transfer processes in an acidic environment. Herein, an ultrathin 2D metal–organic frameworks (MOFs) nanosheet based on cobalt tetra(4-carboxyphenyl) porphine (Co-TCPP NSs) is designed to promote H₂O₂ selectivity up to 96.5 %, accompanied with a remarkable H₂O₂ generation rate of 4677.42 mg·L⁻¹·h⁻¹. Of note, the Co-TCPP NSs also demonstrate its potential for the electro-Fenton process with a cumulative H₂O₂ concentration of 1.21 wt%, highlighting its practical potential in portable H₂O₂ generation electrochemical devices for distributed applications. Our findings demonstrated that the efficient H₂O₂ electrosynthesis could be attributed to the attenuated *OOH adsorption over Co-N₄ moiety on the Co-TCPP NSs, which consequently suppresses its further reduction to form H₂O. This work highlights the potential of 2D MOF architecture for the 2e⁻ ORR and provides an atomic-level insight into the enhanced H₂O₂ selectivity.

The rapid treatment of organic dyes and tetracycline (TC) in industrial wastewater requires highly efficient semiconductor photocatalysts. In this study, the S-Scheme NH₂-MIL-125 (Ti-Zr)/ WO₃ composite material was successfully synthesized using a two-step hydrothermal method. A comprehensive analysis using X-ray Diffraction (XRD), X-ray Photoelectron Spectroscopy (XPS), High Resolution Transmission Electron Microscopy (HRTEM), and Field Emission Scanning Electron Microscopy (FESEM) images revealed that WO₃ nanoparticles are intimately anchored on the NH₂-MIL-125 (Ti-Zr) nanodisks, forming a closely packed heterostructure. The bandgap values of WO₃ and NH₂-MIL-125 (Ti-Zr) were determined to be 2.58 eV and 2.67 eV, respectively. Through Response Surface Methodology (RSM), the optimal photocatalytic conditions for the degradation of simulated pollutants in real aqueous environments by the synthesized photocatalysts were explored. Under the full-spectrum irradiation of a 300 W xenon lamp, the TZW-2 composite photocatalyst exhibited a degradation rate of RhB, MB, and TC solutions as high as 95.7 %, 96.7 %, and 93 % within 90 min, respectively. The excellent photocatalytic performance of the composite photocatalyst originates from the establishment of S-scheme heterojunctions between NH₂-MIL-125 (Ti-Zr) and WO₃, which was confirmed by various characterization techniques such as XPS valence spectra, photoelectrochemistry, and free radical trapping experiments. The excellent stability of the prepared composite photocatalyst was further validated through three cycling test experiments. This work presents new ideas for constructing novel S-Scheme photocatalysts by combining bimetallic cluster MOFs and metal oxides for wastewater treatment.

For the first time, we proposed a novel approach to create enduring and robust fluorescent nanosheets by using MIBK as the backbone to form the 2D MIBK-Sn nanosheets (2D MIBK-Sn NS) for detecting ENR. These nanosheets were synthesized in situ using probe ultrasonication to facilitate the formation of MIBK-based 2D tin nanosheets. The LOD and LOQ for ENR in aqueous solutions was 4.90 and 16.1 nM, respectively. Linear calibration curves were obtained with correlation coefficient (R²) = 0.9920 in a linear range of 0–2 µM. Recovery results from real samples ranged from 90 to 106 % of the nominal values. Milk and urine samples were analyzed at concentrations ranging from 0.3 to 1.7 µM.

The rapid increase in electronic device usage has intensified electromagnetic interference (EMI), necessitating the development of shielding materials that are flexible, lightweight, cost-effective, and highly efficient. Two-dimensional (2D) materials have emerged as promising candidates for next-generation EMI shielding solutions due to their unique properties, such as low weight, mechanical flexibility, and affordability. This review explores the origins of electromagnetic responses and the shielding mechanisms, emphasizing photon-matter interactions. We also examine the instruments, methods, and standards for measuring shielding effectiveness, along with the underlying formulas for shielding efficiency (SE) calculation. Recent advancements in 2D materials for EMI shielding are analyzed, comparing their performance across various frequency ranges to other composites. In addition, the challenges ahead and their prospects are highlighted. We provide insight into forthcoming challenges in finding solutions for the next generation of shielding applications. The findings of this review provide valuable insights into the development of novel materials for EMI shielding and can guide future research in this field.