Showing papers in "Advanced Materials Interfaces in 2021"

Recent Advances of Asymmetric Supercapacitors

Abstract: Asymmetric supercapacitors (ASCs) have attracted significant attentions worldwide owing to their wider voltage window compared with symmetric supercapacitors (SCs). Through combinations of two electrodes with different charge storage mechanisms or different redox reactions, extended operating voltage window can be realized for ASCs. In this article, first the ASCs are classified into two types based on different charge storage mechanisms: electric double-layer capacitive (EDLC)//pseudocapacitive-type ASCs and EDLC// battery-type hybrid SCs. For the EDLC/pseudocapacitive-type ASC, carbon materials are adopted as anode and transition metal oxides including MnO2, RuO2, etc., are utilized as cathodes. For EDLC//battery-type hybrid SCs, carbon materials as anode are combined with metal oxide/hydroxide such as NiO, and Ni(OH)2, etc., as cathode. Recently, Li-ion-based ASCs composed of carbon materials and Li-ion battery-type electrode materials with a Li-containing organic electrolyte show great potentials to be promising alternatives. Some metal oxides/nitrides including InO2, Bi2O3, Fe3O4, Fe2O3, and VN can work in a negative potential range. By coupling another battery/pseudocapacitive electrode, all redox-type ASCs are assembled and their electrochemical performances are widely studied. Then, based on the above categories recent advances of ASCs are summarized. Finally, the challenges and prospects for the development of ASCs are pointed out from perspectives of this study.

A Flexible Self‐Powered UV Photodetector and Optical UV Filter Based on β‐Bi 2 O 3 /SnO 2 Quantum Dots Schottky Heterojunction

Abstract: Recently reported ultraviolet (UV) detectors majorly focus on exploration of photodetection properties like photon absorption and electron-hole pair generation to improve the photoresponsivity. However, UV sensors also have a potential advantage of monitoring the excessive UV exposure on skin. In this work, bismuth oxide/SnO2 quantum dots (QDs) vertical-junction-based self-powered UV photodetector and optical UV filter are demonstrated. β-Bi2O3 nanofibers are synthesized via electrospinning technique and SnO2 QDs are synthesized using a facile, single step hydrothermal process. Detailed morphological studies reveal the formation of 1D-Bi2O3 and 0D-SnO2. The fabricated self-powered Bi2O2/SnO2-based p–n heterojunction device exhibits a maximum responsivity of 62.5 µA W−1 and specific detectivity (D*) of 4.5 × 109 Jones attributing to the high absorption coefficient of β-Bi2O2 nanofibers and SnO2 QDs in the UV region. Further, the 1D β-Bi2O3 nanofibers and 0D SnO2 QDs are coated onto disposable cloth substrate to fabricate the UV optical filter which exhibits an exceptional ultraviolet protection factor of 159 and the photodetector device demonstrates high stability and reproducibility even after 1000 bending cycles. The strategy outlined here paves the way for development of bifunctional, cost-effective design and construction of wearable UV sensors and protective devices for advanced nano-electronic applications.

Effects of External Stimulators on Engineered Skeletal Muscle Tissue Maturation

Abstract: Engineering functional skeletal muscle tissue is an ongoing challenge because of the complexity of the in vivo microenvironment and the various factors that contribute to the development and maintenance of the native tissue. However, the growing understanding of the natural skeletal muscle's microenvironment in vivo, as well as the ability to successfully reproduce these factors in vitro, are contributing to the formation of engineered skeletal muscle tissues (SMTs) with greater biomimetic structure and function. This review first summarizes the structure of skeletal muscle tissue. The role of various hydrogels, biomaterials, and scaffolds as building blocks of complex skeletal muscle structures is then explored. Additionally, the role of external stimuli and regulators that can be applied during in vitro culture that lead to the formation of SMT models with higher functionality is examined. These include various physical, biochemical, electrical, mechanical, and magnetic stimulations, as well as biological stimulation through coculture with fibroblasts, endothelial, or neuronal cells. Finally, examples of recently developed functional tissue models that have been developed for in vitro and in vivo applications and the future outlook for this field are discussed.