Capital Normal University

About: Capital Normal University is a education organization based out in Beijing, China. It is known for research contribution in the topics: Terahertz radiation & Quantum entanglement. The organization has 11441 authors who have published 11988 publications receiving 159071 citations. The organization is also known as: Shǒudū Shīfàn Dàxué.

Ultrathin two-dimensional β-In2S3 nanocrystals: oriented-attachment growth controlled by metal ions and photoelectrochemical properties

Abstract: Ultrathin two-dimensional (2D) semiconductor nanocrystals have attracted much attention of late due to their attractive functional properties. Concurrently, oriented-attachment (OA) growth has been considered as an important growth theory for the construction of various nanocrystals, especially ultrathin 2D nanocrystals. However, all the OA growth procedures reported in the preparation of nanocrystals have been driven by organic ligand molecules so far. In this paper, we report for the first time that a metal ion controlled OA growth to synthesize semiconductor nanocrystals: 2D β-In2S3 nanobelts and nanoflakes with ∼2 nm thickness can be achieved via OA controlled by Ca2+ and Al3+, respectively. Note that Ca2+ and Al3+ are not incorporated into the crystal lattice structure of β-In2S3. β-In2S3 nanobelts and nanoflakes show step-like absorptions in UV-visible spectra. Furthermore, β-In2S3 nanoflakes exhibit the most outstanding photoelectrochemical activity when compared with β-In2S3 nanoparticles and nanobelts.

Iron incorporation affecting the structure and boosting catalytic activity of β-Co(OH)2: exploring the reaction mechanism of ultrathin two-dimensional carbon-free Fe3O4-decorated β-Co(OH)2 nanosheets as efficient oxygen evolution electrocatalysts

Abstract: It is significantly important to develop highly active catalysts for the oxygen evolution reaction (OER) for designing various renewable energy storage and conversion devices. Herein, we report a series of ultrathin two-dimensional (2D) carbon-free Fe3O4-decorated β-Co(OH)2 nanosheets (Fe3O4/Co(OH)2 NSs) as OER electrocatalysts with different Co/Fe mole ratios from 1 to 31. It is found that the different amounts of iron incorporation into Co(OH)2 NSs affects the structure of Fe3O4/Co(OH)2 NSs, while the optimized incorporation boosts the electrocatalytic activity of Co(OH)2 NSs for OER, i.e. the Fe3O4/Co(OH)2 NSs with a Co/Fe molar ratio of 15 demonstrate superior catalytic properties with respect to the lowest overpotential and smallest Tafel slope in alkaline media. First principles calculations used for exploring mechanisms show that Fe3+ from Fe3O4/Co(OH)2 NSs adsorbs water molecules more energetically favorably on the surface and would offer far more improvement of the catalytic activity compared with Fe2+. Combined with structure analysis and calculation results, the better catalytic activity is attributed to the ultrathin structure, high active site exposure, lower adsorption energy towards water molecules and the increased positive charge of adsorbed water molecules. This research paves a way to develop highly active and durable substitutes for noble metal OER electrocatalysts.

Mechanochromic luminogen with aggregation-induced emission: implications for ink-free rewritable paper with high fatigue resistance and low toxicity

Abstract: In this study, we report the synthesis and photoluminescence (PL) behaviour of a new luminogen, DHBA, a functionalized Schiff base. The twisted molecular conformation together with the incorporation of electron donor–acceptor pairs endow the luminogen with both aggregation-induced emission and twisted intramolecular charge transfer properties. The crystalline luminogen shows strong green emission at around 514 nm while the emission colour turns orange-red (562 nm) with a big loss in the quantum efficiency after grinding. The colour of the ground sample can be readily converted back into the initial state though recrystallization by either immersing or fuming in organic solvents. The conversion can be implemented for more than 30 cycles, showing good repeatability. This luminogen probably shows the highest fatigue resistance among all the mechanochromic compounds that have been reported. Inspired by the unique mechanochromism, an archetype of ink-free rewritable paper is developed. Letters and patterns can be easily written using pressure and erased by fumigation in handwriting experiments. The luminogen also enjoys the advantages of a one-pot synthesis and low biotoxicity, providing a reliable candidate for green rewritable paper technology to fulfill demands for sustainability and carbon mitigation.

Proteomic Analysis Reveals Key Proteins and Phosphoproteins upon Seed Germination of Wheat (Triticum aestivum L.)

Abstract: Wheat (Triticum aestivum L.) is one of the oldest cultivated crops and the second most important food crop in the world. Seed germination is the key developmental process in plant growth and development, and poor germination directly affects plant growth and subsequent grain yield. In this study, we performed the first dynamic proteome analysis of wheat seed germination using a two-dimensional differential gel electrophoresis (2D-DIGE)-based proteomic approach. A total of 166 differentially expressed protein (DEP) spots representing 73 unique proteins were identified, which are mainly involved in storage, stress/defense/detoxification, carbohydrate metabolism, photosynthesis, cell metabolism, and transcription/translation/transposition. The identified DEPs and their dynamic expression profiles generally correspond to three distinct seed germination phases after imbibition: storage degradation, physiological processes/morphogenesis, and photosynthesis. Some key DEPs involved in storage substance degradation and plant defense mechanisms, such as globulin 3, sucrose synthase type I, serpin, beta-amylase, and plastid ADP-glucose pyrophosphorylase (AGPase) small subunit, were found to be phosphorylated during seed germination. Particularly, the phosphorylation site Ser(355) was found to be located in the enzyme active region of beta-amylase, which promotes substrate binding. Phosphorylated modification of several proteins could promote storage substance degradation and environmental stress defense during seed germination. The central metabolic pathways involved in wheat seed germination are proposed herein, providing new insights into the molecular mechanisms of cereal seed germination.