Tongji University

About: Tongji University is a education organization based out in Shanghai, China. It is known for research contribution in the topics: Computer science & Population. The organization has 76116 authors who have published 81176 publications receiving 1248911 citations. The organization is also known as: Tongji & Tóngjì Dàxué.

In Vitro Bioactive Characteristics of Borate‐Based Glasses with Controllable Degradation Behavior

Abstract: Silicate-based bioactive glasses undergo incomplete conversion to a calcium phosphate material after in vivo implantation, which severely limits their biomedical application. In this communication, novel borate-based glasses with controllable degradation behavior were developed and their bioactive potential was investigated in vitro. When immersed in a 0.02M K2HPO4 solution at 37°C, these glasses reacted to form a carbonate-substituted hydroxyapatite (c-HA) on their surfaces, indicating their bioactive potential. The conversion rate to c-HA was controlled by adjusting the B2O3/SiO2 ratio in the glass composition. The results indicate the potential application of the borate-based bioactive glass as scaffold materials for bone tissue engineering.

Two-dimensional non-volatile programmable p–n junctions

Abstract: Semiconductor p–n junctions are the elementary building blocks of most electronic and optoelectronic devices. The need for their miniaturization has fuelled the rapid growth of interest in two-dimensional (2D) materials. However, the performance of a p–n junction considerably degrades as its thickness approaches a few nanometres and traditional technologies, such as doping and implantation, become invalid at the nanoscale. Here we report stable non-volatile programmable p–n junctions fabricated from the vertically stacked all-2D semiconductor/insulator/metal layers (WSe2/hexagonal boron nitride/graphene) in a semifloating gate field-effect transistor configuration. The junction exhibits a good rectifying behaviour with a rectification ratio of 104 and photovoltaic properties with a power conversion efficiency up to 4.1% under a 6.8 nW light. Based on the non-volatile programmable properties controlled by gate voltages, the 2D p–n junctions have been exploited for various electronic and optoelectronic applications, such as memories, photovoltaics, logic rectifiers and logic optoelectronic circuits. Stable, nonvolatile, programmable 2D p–n junctions enable realization of high-performance memories, photovoltaics, logic rectifiers and logic optoelectronic circuits.

Electro-Fenton oxidation of pesticides with a novel Fe3O4@Fe2O3/activated carbon aerogel cathode: High activity, wide pH range and catalytic mechanism

Abstract: A novel electro-Fenton (E-Fenton) system with the Fe3O4@Fe2O3/activated carbon aerogel (ACA) composite cathode was firstly constructed in this study. Its application on degrading imidacloprid exhibited highly catalytic efficiency over a wide applicable pH range from 3 to 9. The removal of imidacloprid and TOC achieved to 90% within 30 and 60 min, respectively. The nature of composite cathode was examined by BJH, XRD, SEM, TEM, XPS and FTIR techniques. ACA with high surface area of 2410 m2 g−1 and multiplicated porosities composed of micropores and mesopores worked not only as cathode but also as Fenton catalyst support, enhancing oxidation activity. We proposed reasonable E-Fenton oxidation mechanisms with Fe3O4@Fe2O3/ACA cathode at acidic and basic conditions. At pH 3, it followed a Haber–Weiss mechanism that the dissolved iron ions and surface Fe(II) sites catalyzed the decomposition of H2O2 to generate hydroxyl radicals ( OH). While at pH 9, it was expected the formation and deactivation of H2O2 complex as well as the catalytic decomposition of H2O2 with surface Fe(III) and Fe(II) sites to produce both superoxide anion ( O2−/HO2 ) and hydroxyl radicals ( OH), involving an in situ recycling of iron oxide (FeO·Fe2O3 → Fe2O3).

Ultrathin and Flexible CNTs/MXene/Cellulose Nanofibrils Composite Paper for Electromagnetic Interference Shielding.

Abstract: As the rapid development of portable and wearable devices, different electromagnetic interference (EMI) shielding materials with high efficiency have been desired to eliminate the resulting radiation pollution. However, limited EMI shielding materials are successfully used in practical applications, due to the heavy thickness and absence of sufficient strength or flexibility. Herein, an ultrathin and flexible carbon nanotubes/MXene/cellulose nanofibrils composite paper with gradient and sandwich structure is constructed for EMI shielding application via a facile alternating vacuum-assisted filtration process. The composite paper exhibits outstanding mechanical properties with a tensile strength of 97.9 ± 5.0 MPa and a fracture strain of 4.6 ± 0.2%. Particularly, the paper shows a high electrical conductivity of 2506.6 S m−1 and EMI shielding effectiveness (EMI SE) of 38.4 dB due to the sandwich structure in improving EMI SE, and the gradient structure on regulating the contributions from reflection and absorption. This strategy is of great significance in fabricating ultrathin and flexible composite paper for highly efficient EMI shielding performance and in broadening the practical applications of MXene-based composite materials.