A method for electronic doping of colloidal CdSe nanocrystals (NCs) is reported. Anaerobic photoexcitation of CdSe NCs in the presence of a borohydride hole quencher, Li[Et3BH], yields colloidal n-type CdSe NCs possessing extra conduction-band electrons compensated by cations deposited by the hydride hole quencher. The photodoped NCs possess excellent optical quality and display the key spectroscopic signatures associated with NC n-doping, including a bleach at the absorption edge, appearance of a new IR absorption band, and Auger quenching of the excitonic photoluminescence. Although stable under anaerobic conditions, these spectroscopic changes are all reversed completely upon exposure of the n-doped NCs to air. Chemical titration of the added electrons confirms previous correlations between absorption bleach and electron accumulation and provides a means of quantifying the extent of electron trapping in some NCs. The generality of this photodoping method is demonstrated by initial results on colloidal CdE (E = S, Te) NCs as well as on CdSe quantum dot films.
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http://dx.doi.org/10.1021/ja410825c | DOI Listing |
ACS Appl Mater Interfaces
January 2025
Key Laboratory of Carbon Materials of Zhejiang Province, Wenzhou University, Wenzhou 325035, China.
Developing high-energy-density lithium-sulfur batteries faces serious polysulfide shuttle effects and sluggish conversion kinetics, often necessitating the excessive use of electrolytes, which in turn adversely affects battery performance. Our study introduces a meticulously designed electrocatalyst, Cu-CeO@N/C, to enhance lean-electrolyte lithium-sulfur battery performance. This catalyst, featuring in situ synthesized Cu clusters, regulates oxygen vacancies in CeO and forms Cu-CeO heterojunctions, thereby diminishing sulfur conversion barriers and hastening reaction kinetics through the generation of S/S intermediates.
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January 2025
State Key Laboratory of Fine Chemicals, Research and Development Center of Membrane Science and Technology, School of Chemical Engineering, Dalian University of Technology, Dalian 116024, China.
The electrocatalytic nitrogen reduction reaction (eNRR) is an attractive strategy for the green and distributed production of ammonia (NH); however, it suffers from weak N adsorption and a high energy barrier of hydrogenation. Atomically dispersed metal dual-site catalysts with an optimized electronic structure and exceptional catalytic activity are expected to be competent for knotty hydrogenation reactions including the eNRR. Inspired by the bimetallic FeMo cofactor in biological nitrogenase, herein, an atomically dispersed FeMo dual site anchored in nitrogen-doped carbon is proposed to induce a favorable electronic structure and binding energy.
View Article and Find Full Text PDFMaterials (Basel)
December 2024
Key Laboratory of Advanced Marine Materials, Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo 315201, China.
With the development of diamond technology, its application in the field of electronics has become a new research hotspot. Hydrogen-terminated diamond has the electrical properties of P-type conduction due to the formation of two-dimensional hole gas (2DHG) on its surface. However, due to various scattering mechanisms on the surface, its carrier mobility is limited to 50-200 cm/(Vs).
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December 2024
School of Physics and Electronic Information, Yan'an University, Yan'an 716000, China.
In this work, the rare earth element Ce was incorporated into the A-site of SrBaNbO ferroelectric ceramics, which was prepared using the conventional solid state reaction method and sintered under different procedures. A comprehensive investigation was conducted to assess the impact of Ce doping and varying sintering procedures on both the relaxor characteristics and electrical properties of the ceramics. When sintered at 1300 °C for 4 h, the grains exhibited an isometric shape.
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December 2024
Chemistry Institute, Universidad Nacional Autónoma de México, Circuito Exterior S/N, Ciudad Universitaria, Ciudad de México 04510, Mexico.
In this work, we present the green synthesis of complex - derived from β-hidroxymethylidene indanones by ultrasound, which allowed for the obtaining of compounds in a shorter time and with good yields. These organotin complexes were then doped with cobalt porphine and incorporated into a poly(3,4-ethylenedioxythiophene):poly(4-styrenesulfonate) matrix to manufacture composite semiconductor films. The semiconductor films were characterized through atomic force microscopy, examining their topography, Knoop hardness (around 17 HK), and tensile strength, which varied from 5 × 10 to 7 × 10 Pa.
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