Search

The fluorescence blinking and low multiphoton emission of quantum dots (QDs) have limited their application in lasing, light-emitting diodes, and so on. Coupling of single QDs to plasmonic nanostructures is an effective approach to control the photon properties. Here plasmon–exciton systems including Au nanoparticles and CdZnSe/ZnS QDs were investigated at the single particle level. With the modulation of the local electromagnetic field, the fluorescence intensity of single QDs is increased, accompanied by a significant suppression in blinking behavior, and the lifetime is shortened from 15 ns to 2 ns. Moreover, the second-order photon intensity correlation at zero lag time g2(0) of coupled single QDs is larger than 0.5, indicating an increased probability of multiphoton emission. The enhancement factors of radiative and nonradiative decay rates of QDs coupled with Au nanoparticles are calculated. The sharply increased radiative decay rate can be comparable to the nonradiative Auger rate, leading to dominated multiple exciton radiative recombination with PL intensity enhancement, suppressed blinking, lifetime shortening, and multiphoton emission. The results of the exciton decay dynamics and emission properties of single QDs in this work are helpful in exploring the mechanism of plasmon–exciton interaction and optoelectronic application of single QDs. [ABSTRACT FROM AUTHOR]

Zinc‐ion hybrid capacitors combine the advantages of supercapacitors and batteries and are a promising electrochemical energy storage device. In order to meet the demand for materials with higher energy density and longer cycle time, there is an urgent need to find a zinc‐ion supercapacitor cathode material with lower cost and better electrochemical performance. In this experiment, low‐cost agricultural peanut red skin waste was converted into biomass‐derived carbon material (PSR‐X) with high specific surface area, larger pore volume, and more homogeneous pore size distribution through carbonisation and KOH activation. Due to the interaction of these properties, PSR‐X as the cathode material has higher specific capacity and better multiplicity performance than the zinc‐ion capacitor prepared from the initial carbonised PSR as the cathode material. In addition, the PSR‐4‐based zinc‐ion capacitor has an excellent specific capacity of 86 mAh g−1 at a current density of 0.1 A g−1, a high capacity retention of 55 % even at a high current density of 30 A g−1, and a high energy density of 66.16 Wh kg−1 at a power density of 218.1 W kg−1. What is more gratifying is that the capacitor exhibits an ultra‐long cycle life, with a high capacity retention rate of 85 % after 8,000 charge/discharge cycles at a current density of 1 A g−1. [ABSTRACT FROM AUTHOR]

Ti3C2/TiO2 nanocomposites with high photocatalytic performance are prepared by one-step hydrothermal method. The morphology, microstructure and phase composition of the composites are analyzed and characterized by field emission scanning electron microscopy (SEM) and X-ray diffraction (XRD). The photocatalytic properties of pure TiO2, Ti3C2 and Ti3C2/TiO2 nanocomposites are evaluated using ultraviolet-visible-near-infrared (UV-VIS-NIR, UV-3600) spectrophotometer. The photocatalytic properties of pure TiO2, Ti3C2 and Ti3C2/TiO2 nanocomposites are investigated by using a 500 W xenon lamp to simulate the degradation of organic pollutants under sunlight. Under visible light irradiation, as for Ti3C2/TiO2, the electron and hole are separated more effectively than that of pure TiO2 and Ti3C2 and thus exhibit better photocatalytic performance than TiO2 and Ti3C2. In addition, Ti3C2/TiO2 nanocomposites are heat-treated at different temperatures. The results show that Ti3C2/TiO2-350 obtained by heat treatment at 350 °C exhibits preferable photocatalytic performance and more efficient electron-hole separation behavior than pure TiO2 and Ti3C2. [ABSTRACT FROM AUTHOR]

Perovskite structural metal oxides as electrode materials present promising and potential properties due to excellent storage characteristics. Herein, series of perovskite type LaMnO _3 nanopowders were synthesized by the ‘sol-gel’ method with a heat treatment at different temperatures (700 °C–900 °C) for different times. The morphology characterization, structures and electrochemical performances were investigated. The preferable sample for electrochemical energy storage device can be obtained at 900 °C with 2 h annealing. Furthermore, to improve the properties of the electrode materials, the samples were combined and rectified with reduced graphene oxide (rGO) and strontium (Sr), respectively. The results indicate that the rGO/Sr-doped LaMnO _3 oxide materials have excellent electrochemical properties. These findings are beneficial for the selection and preparation of electrode materials.