Microwave absorption is a critical challenge with progression in electronics, where fine structural designing of absorbent materials plays an effective role in optimizing their microwave absorption properties. Here, we have developed FeO@C (FC) and Fe-FeO@C (FFC) hybrid nanorings via a hydrothermal method coupled with a chemical catalytic vapor deposition technique. FC and FFC hybrid nanorings have fine carbon coating while their size can easily be tunable in a certain range from 80-130 to 90-140 nm. The optimized FC and FFC hybrid nanorings bear minimum reflection loss (RL) values of -39.1 dB at 15.9 GHz and -32.9 dB at 17.1 GHz, respectively, whereas FFC shows an effective absorption bandwidth (RL values < -10 dB) ranged from 5.2 to 18 GHz. Such an enhanced microwave absorption performance of hybrid nanorings is mainly due to the suitable impedance characteristics, multilevel interfaces, and polarization features in nanorings. This work provides an approach to design hybrid materials having a complex structure to enhance the microwave absorption properties.

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The proportion of Fe2+ and Fe3+ in the Fe-based nanozymes is a key point in determining their catalytic activity. However, it is hard to adjust Fe2+/Fe3+ ratio in the nanozyme...

Carbon-based materials are typical and commercially active electrode for supercapacitors due to their advantages such as low cost, good stability and easy availability. In the light of energy storage, supercapacitors mechanism is classified into EDLCs (electrochemical double layer capacitors) and pseudocapacitors. Multidimensional carbon nanomaterials (active carbon, carbon nanotube, graphene, etc.), carbon-based composite and corresponding electrolyte are the critical and important factor in the eyes of researcher. In this minireview, we will discuss the storage mechanism and summarize recent developed novel carbon and carbon-based materials in supercapacitors. The techniques to design the novel nanostructure and high performance electrodematerials that facilitate charge transfer to achieve high energy and power densities will also be discussed.

Quartz crystal microbalance (QCM) is one of the powerful tools for the studies of molecular recognition and chiral discrimination. Its efficiency mainly relies on the design of the functional sensitive layer on the electrode surface. However,t he organic sensitive layer may easily cause dissipation of oscillation or detachmentand weaken the signal transfer during the molecular recognition processes.I nt his work, we reveal for the first time that the bare metal surface without the organic selector layer has the capability for chiral recognition in the QCM system. During the adsorption of various chiral amino acids,r elatively higher selectivity of D-enantiomers on gold (Au) surface was shown by the QCM detection. Based on analyses of the surface crystalline structure and density functional theory calculations,wedemonstrate that the chiral nature of Au surface playsanimportant role in the selective binding of specific D-amino acids.These results may open new insights on chiral detection by QCM system. It will also promote the construction of novel chiral sensing systems with both efficient detection and separation capability.

Quartz crystal microbalance (QCM) has been widely used for various sensing applications, including chirality detection due to the high sensitivity to nanogram or picogram mass changes, fast response, real-time detection, easy operation, suitability in different media, and low experimental cost. The sensing performance of QCM is dependent on the surface design of the recognition layers. Various strategies have been employed for studying the relationship between the structural features and the specific detection of chiral isomers. This review provides an overview of the construction of chiral sensing layers by various nanostructures and materials in the QCM system, which include organic molecules, supermolecular assemblies, inorganic nanostructures, and metal surfaces. The sensing mechanisms based on these surface nanostructures and the related potentials for chiral detection by the QCM system are also summarized.

Quartz crystal microbalance (QCM) is one of the powerful tools for the studies of molecular recognition and chiral discrimination. Its efficiency mainly relies on the design of the functional sensitive layer on the electrode surface. However, the organic sensitive layer may easily cause dissipation of oscillation or detachment and weaken the signal transfer during the molecular recognition processes. In this work, we reveal for the first time that the bare metal surface without the organic selector layer has the capability for chiral recognition in the QCM system. During the adsorption of various chiral amino acids, relatively higher selectivity of D‐enantiomers on gold (Au) surface was shown by the QCM detection. Based on analyses of the surface crystalline structure and density functional theory calculations, we demonstrate that the chiral nature of Au surface plays an important role in the selective binding of specific D‐amino acids. These results may open new insights on chiral detection by QCM system. It will also promote the construction of novel chiral sensing systems with both efficient detection and separation capability.