58 research outputs found
Re-ranking Method Based on Topic Word Pairs
PACLIC 20 / Wuhan, China / 1-3 November, 200
Phase Modulation of (1T-2H)-MoSe2/TiC-C Shell/Core Arrays via Nitrogen Doping for Highly Efficient Hydrogen Evolution Reaction
Tailoring molybdenum selenide electrocatalysts with tunable phase and morphology is of great importance for advancement of hydrogen evolution reaction (HER). In this work, phaseâ and morphologyâmodulated Nâdoped MoSe2/TiCâC shell/core arrays through a facile hydrothermal and postannealing treatment strategy are reported. Highly conductive TiCâC nanorod arrays serve as the backbone for MoSe2 nanosheets to form highâquality MoSe2/TiCâC shell/core arrays. Impressively, continuous phase modulation of MoSe2 is realized on the MoSe2/TiCâC arrays. Except for the pure 1TâMoSe2 and 2HâMoSe2, mixed (1Tâ2H)âMoSe2 nanosheets are achieved in the NâMoSe2 by N doping and demonstrated by spherical aberration electron microscope. Plausible mechanism of phase transformation and different doping sites of N atom are proposed via theoretical calculation. The much smaller energy barrier, longer HSe bond length, and diminished bandgap endow NâMoSe2/TiCâC arrays with substantially superior HER performance compared to 1T and 2H phase counterparts. Impressively, the designed NâMoSe2/TiCâC arrays exhibit a low overpotential of 137 mV at a large current density of 100 mA cmâ2, and a small Tafel slope of 32 mV decâ1. Our results pave the way to unravel the enhancement mechanism of HER on 2D transition metal dichalcogenides by N doping
Unveiling the additive-assisted oriented growth of perovskite crystallite for high performance light-emitting diodes.
Solution-processed metal halide perovskites have been recognized as one of the most promising semiconductors, with applications in light-emitting diodes (LEDs), solar cells and lasers. Various additives have been widely used in perovskite precursor solutions, aiming to improve the formed perovskite film quality through passivating defects and controlling the crystallinity. The additive's role of defect passivation has been intensively investigated, while a deep understanding of how additives influence the crystallization process of perovskites is lacking. Here, we reveal a general additive-assisted crystal formation pathway for FAPbI3 perovskite with vertical orientation, by tracking the chemical interaction in the precursor solution and crystallographic evolution during the film formation process. The resulting understanding motivates us to use a new additive with multi-functional groups, 2-(2-(2-Aminoethoxy)ethoxy)acetic acid, which can facilitate the orientated growth of perovskite and passivate defects, leading to perovskite layer with high crystallinity and low defect density and thereby record-high performance NIR perovskite LEDs (~800ânm emission peak, a peak external quantum efficiency of 22.2% with enhanced stability)
Integrated carbon nanospheres arrays as anode materials for boosted sodium ion storage
Developing cost-effective advanced carbon anode is critical for innovation of sodium ion batteries. Herein, we develop a powerful combined method for rational synthesis of free-standing binder-free carbon nanospheres arrays via chemical bath plus hydrothermal process. Impressively, carbon spheres with diameters of 150â250 nm are randomly interconnected with each other forming highly porous arrays. Positive advantages including large porosity, high surface and strong mechanical stability are combined in the carbon nanospheres arrays. The obtained carbon nanospheres arrays are tested as anode material for sodium ion batteries (SIBs) and deliver a high reversible capacity of 102 mAh gâ1 and keep a capacity retention of 95% after 100 cycles at a current density of 0.25 A gâ1 and good rate performance (65 mAh gâ1 at a high current density of 2 A gâ1). The good electrochemical performance is attributed to the stable porous nanosphere structure with fast ion/electron transfer characteristics
A BIL Population Derived from G. hirsutum and G. barbadense Provides a Resource for Cotton Genetics and Breeding.
To provide a resource for cotton genetics and breeding, an interspecific hybridization between Gossypium hirsutum cv. Emian22 and G. barbadense acc. 3-79 was made. A population of 54 BILs (backcross inbred lines, BC1F8) was developed with the aim of transferring G. barbadense genes into G. hirsutum in order to genetically analyze these genes' function in a G. hirsutum background and create new germplasms for breeding. Preliminary investigation of the morphological traits showed that the BILs had diverse variations in plant architecture, seed size, and fuzz color; the related traits of yield and fiber quality evaluated in 4 environments also showed abundant phenotypic variation. In order to explore the molecular diversity of the BIL population, 446 SSR markers selected at an average genetic distance of 10 cM from our interspecific linkage map were used to genotype the BIL population. A total of 393 polymorphic loci accounting for 84.4% MAF (major allele frequency) > 0.05 and 922 allele loci were detected, and the Shannon diversity index (I) was 0.417 per locus. The average introgression segment length was 16.24 cM, and an average of 29.53 segments were introgressed in each BIL line with an average background recovery of 79.8%. QTL mapping revealed 58 QTL associated with fiber quality and yield traits, and 47 favored alleles derived from the donor parent were discovered. This study demonstrated that the interspecific BIL population was enriched with much phenotypic and molecular variation which could be a resource for cotton genetics and breeding
Transition Metal Carbides and Nitrides in Energy Storage and Conversion
High-performance electrode materials are the key to advances in the areas of energy conversion and storage (e.g., fuel cells and batteries). In this Review, recent progress in the synthesis and electrochemical application of transition metal carbides (TMCs) and nitrides (TMNs) for energy storage and conversion is summarized. Their electrochemical properties in Li-ion and Na-ion batteries as well as in supercapacitors, and electrocatalytic reactions (oxygen evolution and reduction reactions, and hydrogen evolution reaction) are discussed in association with their crystal structure/morphology/composition. Advantages and benefits of nanostructuring (e.g., 2D MXenes) are highlighted. Prospects of future research trends in rational design of high-performance TMCs and TMNs electrodes are provided at the end.Published versio
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