- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
Few-Layered 1T-MoS2-Modified ZnCoS Solid-Solution Hollow Dodecahedra for Enhanced Photocatalytic Hydrogen Evolution
摘要： Enhancing solar hydrogen production efficiency essentially relies on the modification of low-cost and highly stable photocatalysts with enhanced light-harvesting ability and promoted charge transfer kinetics. Herein, we report a facile synthetic route to modify the performance of a low-cost metal sulfide semiconductor, consisting of the bimetallic metal-organic frameworks (MOFs)-templating and the simultaneous sulfidation of the photocatalyst and loading of MoS2 co-catalyst. The mutual sulfur atom shared by all the transition metal sulfides allowed the formation of ZnCoS solid-solution structure and the stabilization of the metallic 1T-MoS2 phase, contributing to the photocatalytic activity enhancement from several aspects: i) extending the light absorption region from UV to visible and near-infrared light by the incorporation of another transition metal sulfide species, i.e., CoS; ii) achieving abundant catalytically active sites, and high electronic conductivity between the intimately contacted ZnCoS and MoS2 by loading few-layered 1T-MoS2; and iii) further increasing its capability of utilizing the single-photon with relatively higher energy in the UV-visible region by the involvement of a metal-free photosensitizer–Eosin Y (EY). As a consequence, the novel few-layered 1T MoS2-modified hollow Zn0.5Co0.5S rhombic dodecahedra exhibited a high photocatalytic H2 production activity of 15.47 mmol h-1 g-1 with an apparent quantum efficiency of 30.3% at 420 nm and stability with 90% H2 evolution retention even after seven consecutive runs for total 35 h irradiation. This novel approach to prepare advanced materials could be further extended to the phase-controllable preparation of MoS2 and the discovery of other transition metal chalcogenides with high activity and stability in various applications.
关键词： ZnCoS solid-solution,hollow dodecahedra,dye-sensitization,1T-MoS2,photocatalytic hydrogen evolution,MOF-templating
更新于2025-11-21 10:59:37
-
One-step preparation of Bi4O5BrxI2?x solid solution with superior photocatalytic performance for organic pollutants degradation under visible light
摘要： Highly e?cient photocatalyst is the demand for controlling environmental pollution, especially the toxic and refractory organic contaminants. Herein, a series of bismuth-rich Bi4O5BrxI2?x solid solution photocatalysts were prepared through a one-step solvothermal method by adjusting the molar ratio of Br/I, which can e?ectively degrade organic pollutants of phenol and Rhodamine B (RhB). The structure and morphology of the photocatalysts were characterized by X-ray di?raction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscope (SEM), transmission electron microscope (TEM) and high resolution transmission electron microscope (HRTEM). The results indicated that Bi4O5BrxI2?x solid solution photocatalysts were successfully synthesized. The obtained samples showed superior photocatalytic activities toward phenol and RhB under visible light irradiation. Besides, the photocatalytic performances can be optimized by changing the ratio of Br/I. When the ratio of Br/I was 1:1, the obtained Bi4O5BrxI2?x solid solution exhibited the highest photocatalytic performance, which was nearly 6.4 and 8.5 times higher than that of pure Bi4O5Br2 and Bi4O5I2 for phenol degradation, respectively. The enhancement can be ascribed to the high e?cient separation of photogenerated electron-hole pairs in Bi4O5BrxI2?x solid solution, which was con?rmed by the corresponding optical and photoelectrochemical characterizations.
关键词： One-step synthesis,Photocatalytic,Bi4O5BrxI2?x solid solution,Bismuth-rich
更新于2025-09-23 15:23:52
-
Photocatalytic overall water splitting on isolated semiconductor photocatalyst sites in an ordered mesoporous silica matrix: A multiscale strategy
摘要： Photocatalytic overall water splitting (OWS) in a stoichiometric ratio has attracted increasing attention for the realization of a sustainable, environmentally friendly future. However, this reaction exhibits sluggish kinetics due to efficiency limitations of the involved steps, including photon absorption, electron transfer, and the reactions that occur at triple-phase boundary regions. Herein, we report a general multiscale strategy to address this challenge by designing a model composite catalyst with a high loading density of isolated Bi0.5Y0.5VO4 nanocrystals, as building blocks, dispersed in a hexagonally ordered mesoporous silica matrix. In contrast to the well-recognized heterojunction formed between different semiconductors, we show that confined growth favours the formation of isolated quaternary solid-solution photocatalysts (Bi0.5Y0.5VO4), which can further interface with the insulating silica to overcome temperature limitations and exhibit enhanced photon absorption and electrochemical and mass transfer properties due to the transparent periodic porous structure of silica and the as-formed small nanocrystals with high crystallinity and a passivated surface. When the semiconductor photocatalyst is incorporated with the inert silica insulator, this nanoarchitecture does not inhibit the OWS activity but actually delivers a 10-fold higher OWS activity than bulk Bi0.5Y0.5VO4 prepared by the conventional solid-state method.
关键词： Multiscale strategy,Photocatalysis,Isolated solid-solution nanocrystal,Overall water splitting,Mesoporous composite
更新于2025-09-23 15:23:52
-
Persian buttercup-like BiOBrxCl1-x Solid Solution for Photocatalytic overall CO2 Reduction to CO and O2
摘要： The photocatalytic overall conversion of CO2 with H2O to chemical fuel and oxygen mimicking natural photosynthesis is a huge challenge in photocatalysis. This work shows the achievement of the solar-driven photocatalytic overall CO2 reduction with H2O to CO and O2 over a Persian buttercup-like BiOBrxCl1-x solid solution. A CO generation rate of 15.86 μmol g?1 h?1 with the approximate stoichiometric O2 evolution is yielded on BiOBr0.6Cl0.4 solid solution under simulated solar light irradiation, which was about 7.5 and 10.2 times higher than that of pure BiOCl (2.11 μmol g?1 h?1) and BiOBr (1.55 μmol g?1 h?1), respectively. The enhanced photoactivity is contributed to the mediate band gap and energy level tuned by the formation of BiOBrxCl1-x solid solution to facilitate the separation of photogenerated charges. Besides the unique electron structure, the photoinduced oxygen vacancy (OV) formed on BiOBrxCl1-x solid solution also plays an important role in the CO2 reduction.
关键词： CO2 conversion,BiOBrxCl1-x,Solid solution,Photocatalysis
更新于2025-09-23 15:21:21
-
Enhanced photovoltaic effects in ferroelectric solid solution thin films with nanodomains
摘要： Domain structures in polar materials provide an additional degree of freedom to tune ferroelectric photovoltaic (PV) effects. One of the approaches to control domain structures is to form a solid solution with analogs in different symmetries. In this study, we investigate the influence of domain structures on the PV properties of ferroelectric thin films in the xBaTiO3–(1?x)BiFeO3 (BT–BFO) solid-solution system (x = 0.1 and 0.2). We found that a substitution of BT for BFO substantially decreases the domain size down to several tens of nanometers, leading to an enhanced PV response owing to a marked contribution of the domain-wall PV effect.
关键词： solid solution,ferroelectric,photovoltaic,nanodomains,domain-wall PV effect
更新于2025-09-23 15:21:01
-
Optimization of Temperature Dependence of Heteronanolaser Threshold Current with Account for the Thickness and Dielectric Properties of the Heterostructure Waveguide Nano-Layer Material
摘要： An exact problem of the electromagnetic wave propagation in a multilayer heteronanostructure with complex values of the dielectric constant (permittivity) is solved. The contribution to the refractive index of an additive to the dielectric constant due to the injected carriers is taken into account. A heterostructure based on a nanosystem used for the manufacture of lasers in the range 0.94–1.14 μm is considered. The methods and approaches used are also applicable for optimizing multilayer structures based on other solid solutions and those with several quantum wells. Based on the calculations of the temperature dependence of the radiation characteristics of injection lasers based on heteronanostructures, it was shown that the anomalous behavior of the temperature dependence of the threshold current is associated with a weakening of the waveguide properties of their active region. In accordance with the calculation results, the heteronanotructures parameters of injection lasers were optimized with respect to the thickness and dielectric properties of the waveguide nanolayer material, which made it possible to significantly reduce the temperature dependence of their radiative characteristics.
关键词： solid solution,threshold current,optimization of the heterostructure parameters,local gain,mode gain,injection lasers,optical waveguide,heteronanostructure,quantum-well heterostructures
更新于2025-09-23 15:21:01
-
Ultrathin sheetlike BiOAc0.67I0.33 solid solution with optimal energy levels and enhanced visible-light photocatalytic activity
摘要： BiO(CH3COO)xI1-x (denoted as BiOAcxI1-x) solid solutions were easily synthesized by co-precipitation method. The BiOAcxI1-x solid solutions with x = 0.67 possessed the highest visible-light photocatalytic activity for the degradation of multiple pollutants like rhodamine B (RhB), malachite green (MG) and colorless salicylic acid (SA) due to ultrathin sheetlike structures and optimal energy levels, which could e?ectively impede the re-combination of photogenerated electron-hole pairs. High separation e?ciency of charge carriers was further con?rmed by photoelectrochemical techniques. Various factors to a?ect photocatalytic performance of the BiOAcxI1-x were investigated in detail and the corresponding photocatalytic mechanism was proposed.
关键词： BiOAcI solid solution,Co-precipitation,Photocatalysis,Energy level
更新于2025-09-23 15:21:01
-
Tunable luminescence of (Sr <sub/>1?x</sub> Ca <sub/>x</sub> ) <sub/>1.97</sub> MgSi <sub/>2</sub> O <sub/>7</sub> :0.03Eu <sup>2+</sup> solid solution phosphors for cirtopic LEDs
摘要： In order to realize the 490 nm single-peak emission for cirtopic light-emitting diodes (LEDs), a series of iso-structural (Sr1?xCax)1.97MgSi2O7:0.03Eu2+ (x = 0, 0.2, 0.3, 0.4, 0.8, 1) phosphors with melilite structure have been prepared by traditional solid-state reaction. The x-ray Diffraction (XRD) patterns and regular lattice parameters confirm the formation of (Sr1?xCax)2MgSi2O7 solid solution. Broad band excitation spectra were observed in the ultraviolet region of these phosphors. The photoluminescence spectra of (Sr1?xCax)1.97MgSi2O7:0.03Eu2+ solid solution phosphors give continuously tunable emission from 466 [Sr2MgSi2O7:Eu2+, (x = 0)] to 527 nm [Ca2MgSi2O7:Eu2+, (x = 1)]. Phosphors with an illuminating centre at 486 and 490 nm were obtained when adjusting the x value to 0.3 and 0.4 respectively. By measuring the quantum efficiency (QE) and contrasting with the spectral sensitivity function of cirtopic, (Sr1?xCax)1.97MgSi2O7:0.03Eu2+ (x = 0.3, 0.4) phosphors have potential value in cirtopic vision.
关键词： solid solution phosphor,melilite structure,cirtopic LED
更新于2025-09-23 15:19:57
-
Direct-indirect GeSn band structure formation by laser Radiation: The enhancement of Sn solubility in Ge
摘要： Low equilibrium solid solubility of Sn atoms in Ge (less than 1%) leads to limitations in application of this material for IR detectors and emitters. Providing of non-equilibrium conditions by powerful pulsed laser radiation can be successfully applied for enhancement of solubility of impurity atoms in the host material. Here we present laser-induced monotonous redistribution of Sn atoms in Ge, based on the thermogradient effect aiming overcoming equilibrium limitations in the solubility. We applied pulsed nanosecond laser radiation to epitaxial Ge0.96Sn0.04 layer grown on Si substrate to increase Sn atomic concentration up to 14% at the surface layer. As a result, indirect-direct graded bandgap GeSn structure was formed. The TEM/EDS cross-section analysis, X-ray photoelectron spectroscopy, Raman and UV reflection spectra confirmed the increase of Sn atomic content at the surface by order of magnitude. SEM and AFM imaging provided evident microstructure changes, while carrier lifetime changes, determined by differential transmittivity, were not observed, indicating that laser irradiation does not generate defects which reduce electronic quality of the material.
关键词： Laser radiation,Thermogradient effect,Solid solution,Carrier recombination,GeSn
更新于2025-09-23 15:19:57
-
CdS quantum dots modified surface oxygen vacancy defect ZnO1-x-TiO2-x solid solution sphere as Z-Scheme heterojunctions for efficient visible light-driven photothermal-photocatalytic performance
摘要： CdS quantum dots (QDs) modified surface oxygen vacancy defect ZnO1-x-TiO2-x solid solution spheres were prepared by using a hydrothermal, chemical reduction and electroless plating strategy, which have sufficient negative conduction band potential while having a photoresponse in visible light region. According to the band energy alignment, Z-scheme structure is formed, which favors spatial charge separation. The obtained CdS QDs/ZnO1-x-TiO2-x heterojunctions with the gap of ~2.09 eV exhibit excellent photothermal performance and photocatalytic degradation of bisphenol A (~99.5%), 2,6-dichlorophenol (~99.1%), and 2,4,5-trichlorophenol (~98.9%). It can be attributed to the following reasons: (1) a solid solution strategy can be used to enhance the photocatalytic activity of a given semiconductor photocatalyst. (2) The presence of oxygen defects can extend the photoresponse to visible light region. (3) TiO2-x-ZnO1-x and CdS QDs can form Z-Scheme heterojunctions to increase the spatial separation of photogenerated electron-holes, which can promote photocatalytic performance. After recycle test, the resultant catalysts show high stability, which has superiority in practical application. So this novel CdS QDs modified surface oxygen vacancy defect ZnO1-x-TiO2-x solid solution sphere will have potential applications in environmental fields.
关键词： Photothermal-photocatalytic,Solid solution,Oxygen vacancy defect,Z-Scheme heterojunction,Quantum dot
更新于2025-09-23 15:19:57