g-C3N4-BiOBr复合材料制备及可见光催化性能

利用原位沉积法将Bi OBr纳米片生长到g-C_3N_4表面,制得g-C_3N_4-Bi OBr p-n型异质结复合光催化剂。采用X射线衍射(XRD)、红外光谱(FTIR)、场发射扫描电子显微镜(FE-SEM)、透射电子显微镜(TEM)、紫外可见漫反射(UV-Vis-DRS)和荧光光谱(PL)等测试对光催化剂结构和性能进行表征。通过可见光辐照降解甲基橙水溶液检测评估复合光催化剂光催化活性。研究结果表明:复合光催化剂由Bi OBr和g-C_3N_4两相组成,Bi OBr纳米片在片状g-C_3N_4表面快速形核生长形成面-面复合结构。相比于纯相g-C_3N_4和Bi OBr,g-C_3N_4-Bi OBr复合材料具有更强可见光吸收能力,吸收带边红移。在可见光辐照100 min后,性能最佳的2:8 gC_3N_4-Bi OBr复合光催化剂光催化活性分别是纯相g-C_3N_4和Bi OBr的1.8和1.2倍,经过4次循环实验后,其降解率仍达84%,说明复合结构光催化剂催化性能和稳定性增强。复合光催化剂的荧光强度显著降低,说明光生载流子复合得到了有效抑制。复合光催化剂催化性能的提高归因于p-n型异质结促进电荷有效分离、抑制电子-空穴复合和吸收光波长范围的扩展,相比单一成分材料具有更好的催化活性和稳定性。自由基捕获实验证明,可见光降解甲基橙光催化过程中的主要活性成分为空穴,并据此提出了可能的光催化机理。     

油水自组装制备Ag@AgBr/BiOBr高效可见光催化剂

采用油水自组装法制备Ag@Ag Br表面修饰三维花状结构Bi OBr复合光催化剂(Ag@Ag Br/Bi OBr),利用XRD、SEM、TEM、EDX、DRS、XPS、PL及EIS等手段对光催化剂的结构和性能进行了表征,并研究了可见光下降解亚甲基蓝(MB)的催化性能。研究表明:Ag@Ag Br粒径约为20 nm,均匀分散在花状微球Bi OBr表面上;贵金属Ag的表面等离子体效应可显著增强可见光利用率,并有效促进光生电子空穴对的分离,Ag@Ag Br(15wt%)/Bi OBr光催化剂展现出最优的催化活性,可见光照射30 min对MB的降解率将近90%,淬灭实验表明·O2-,h+和Br0均为活性物种。结合理论分析与实验结果提出复合光催化剂的降解机理。     

异质结Bi_2WO_6/ZnO复合光催化剂的制备及其光催化降解含酚废水的研究

采用水热法制备了一系列Bi2WO6/Zn O异质结光催化剂,并对其进行X射线衍射(XRD)、紫外-可见光谱(UV-Vis DRS)、扫描电镜(SEM)、光电子能谱(EDS)等手段对其结构性质进行了表征。在含酚废水的液相反应体系中,研究了异质结Bi2WO6/Zn O复合光催化剂光催化降解苯酚的性能。结果表明,Bi2WO6/Zn O异质结的形成可以有效的抑制光生电子和空穴对的结合,使其光催化活性明显优于纯的Zn O和Bi2WO6;另外,异质结型Bi2WO6/Zn O复合光催化剂的表面OH·自由基更有利于光催化活性的提高。当Bi2WO6复合量为4wt%时,异质结Bi2WO6/Zn O复合光催化剂光催化降解苯酚的效果最佳。     

Z型可见光催化剂Au NPs/g-C_3N_4/BiOBr的构建及其光催化性能（英文）

通过水热和原位还原法制备了一种新型Z型异质结三元复合材料Au NPs/g-C_3N_4/BiOBr,并通过X射线衍射、X射线光电子能谱、透射电子显微镜、紫外-可见漫反射光谱和光致发光发射光谱等技术对材料的形貌、结构进行了表征。通过在可见光下降解苯酚来评价光催化剂的活性。研究发现,Au NPs/g-C3N4/BiOBr显示出增强的光催化活性,对苯酚的降解能力是g-C_3N_4的3倍,是BiOBr的2.5倍。这可归因于三元复合材料的窄带隙(2.10 eV)、Z型机理对光生电子-空穴对的有效分离和Au纳米颗粒的表面等离子体共振效应(SPR)。     

BiOI/Bi_2WO_6对甲基橙和苯酚的光催化降解及光催化机理(英文)

采用简单的沉积方法制备了不同碘化氧铋含量的BiOI/Bi2WO6光催化剂,通过X射线衍射(XRD)、扫描电子显微镜(SEM)、高分辨透射电子显微镜(HR-TEM)、紫外-可见漫反射光谱(UV-Vis DRS)和BET比表面积测量对其进行了表征。在紫外和可见光的照射下,使用甲基橙和苯酚的光催化降解评价了BiOI/Bi2WO6催化剂的光催化性能。结果表明:与商业P25和纯Bi2WO6相比,13.2%BiOI/Bi2WO6光催化剂具有更高的紫外和可见光催化性能。这明显增加的光催化活性主要归功于光生电子和空穴在Bi2WO6和BiOI界面上的有效转移,降低了电子-空穴对的复合。基于BiOI和Bi2WO6的能带结构,提出了光生载流子的一种转移过程。自由基清除剂的实验表明,·OH,h+,·O2-和H2O2,特别是h+,共同支配了甲基橙和苯酚的光催化降解过程。     

Z型可见光催化剂Au NPs/g-C3N4/BiOBr的构建及其光催化性能

通过水热和原位还原法制备了一种新型Z型异质结三元复合材料Au NPs/g-C₃N₄/BiOBr,并通过X射线衍射、X射线光电子能谱、透射电子显微镜、紫外-可见漫反射光谱和光致发光发射光谱等技术对材料的形貌、结构进行了表征。通过在可见光下降解苯酚来评价光催化剂的活性。研究发现,Au NPs/g-C₃N₄/BiOBr显示出增强的光催化活性,对苯酚的降解能力是g-C₃N₄的3倍,是BiOBr的2.5倍。这可归因于三元复合材料的窄带隙（2.10eV）、Z型机理对光生电子-空穴对的有效分离和Au纳米颗粒的表面等离子体共振效应（SPR）。     

分级结构CdS QDs/BiOCl复合光催化剂的制备及其对有机污染物的降解

采用简单液相沉积法制备了分级结构Cd S QDs/Bi OCl复合光催化剂,以XRD,SEM,TEM,HRTEM,XPS,EDS,UV-Vis DRS,PL等测试方法分别表征了样品的物相、形貌、组成、元素含量、光吸收性能以及光电特性,并以罗丹明B(Rh B)和苯酚为模型污染物,分别在可见光和紫外光下评价Cd S QDs/Bi OCl复合光催化剂的催化性能。测试结果表明,粒径为5.5μm的Bi OCl微球由大量纳米片有序堆积而成,所负载的粒径为10~20 nm的Cd S QDs均匀分布在Bi OCl纳米片表面。与纯Bi OCl和Cd S QDs/Bi OCl相比,Cd S QDs/Bi OCl-3%表现出最佳的光催化性能,其对Rh B和苯酚的降解速率常数分别是纯Bi OCl的2.6倍和5.3倍。Cd S QDs/Bi OCl复合光催化剂性能的提高可归结于,分级结构Bi OCl有效防止了片层堆积,有助于Cd S QDs的负载,另外,Cd S QDs的负载拓展了复合光催化剂的光吸收性能,均匀分布的Cd S QDs与Bi OCl形成的异质结促进了光生电子-空穴对的有效分离。     

g-C_3N_4/BiOBr异质结光催化剂的制备与可见光催化活性

以三聚氰胺作为合成g-C_3N_4纳米片的前躯体,以Bi(NO3)3·5H2O和KBr作为合成BiOBr的原料,采用水热法构建g-C_3N_4/Bi OBr二维异质结可见光催化剂,有效的晶面复合和合适的能带组合有助于增强g-C_3N_4和BiOBr的可见光催化活性。利用X射线衍射(XRD)、透射电镜(TEM)、X射线光电子能谱(XPS)、光致发光光谱(PL)和紫外-可见漫反射光谱(UVvis DRS)等方法表征其结构、光学性质以及组成结构。在可见光(λ420 nm)下以光催化降解RhB来评价合成催化剂的光催化活性,结果表明,g-C_3N_4/BiOBr光催化降解罗丹明B(Rh B)的效率高于单体g-C_3N_4和BiOBr,并对g-C_3N_4/BiOBr增强可见光催化RhB机理进行解释。     

直接Z型MIL-100(Fe)/BiOBr异质结的构建及光芬顿降解磺胺甲恶唑的性能

通过原位共沉淀法可控制备了系列直接Z型MIL-100(Fe)/Bi OBr异质结。使用粉末X射线衍射(PXRD)、傅里叶红外变换(FTIR)光谱、紫外可见漫反射光谱(UV-Vis DRS)、扫描电镜(SEM)、高倍透射电镜(HRTEM)以及X射线光电子能谱(XPS)对MIL-100(Fe)/Bi OBr异质结晶体结构、微观形貌、光学性能、化学组成进行表征。以低功率发光二级管可见光为光源,探究了MIL-100(Fe)/Bi OBr异质结光芬顿降解磺胺甲恶唑(SMX)性能。最佳反应体系MB-7/Vis/H₂O₂(MB-7是MIL-100(Fe)质量为Bi OBr质量的70%时制备的样品)在光源照射70 min后可降解99.8%SMX(5 mg·L^-1)。同时,还考察了H₂O₂浓度、催化剂投加量、p H值以及无机阴离子对MB-7/Vis/H₂O₂降解SMX影响。MB-7/Vis/H₂O₂能够在经过...     

TiO2-石墨烯光催化剂：制备及引入石墨烯的方法对光催化性能的影响

利用溶胶-凝胶法原位制备了二氧化钛/石墨烯(TiO2-GE)复合光催化剂,研究了纯TiO2以及不同方法制备的TiO2-GE复合光催化剂对亚甲基蓝及罗丹明B光催化降解性能。结果表明:石墨烯的引入提高了TiO2的光催活性,这主要是得益于石墨烯优异的电子传输性能及较好吸附特性。不同方法制备TiO2-GE复合催化剂的光催化活性也存在较大差别。原位制备的TiO2-GE复合光催化剂表现出最佳的光催化活性。     

n-p异质结型CdS/BiOBr复合光催化剂的制备及性能

采用两步水热法制备了CdS/BiOBr复合光催化剂,并通过X射线粉末衍射(XRD)、扫描电子显微镜(SEM)、透射电子显微镜(TEM)和紫外-可见漫反射光谱(UV-Vis DRS)等手段对其物相、表面结构、光响应性等性质进行了表征.结果表明,合成的CdS/BiOBr复合材料是n-p型异质结,由CdS颗粒裹附在BiOBr纳米球的表面构成,这种结构不仅具有良好的可见光响应范围,且有利于光生电子的迁移,并有效地抑制光生电子/空穴对的复合.通过光催化降解模拟染料废水和光催化脱除模拟含硫燃料评价了CdS/BiOBr复合材料的可见光催化性能.结果表明,6%(质量分数)CdS/BiOBr降解次甲基蓝的拟一级动力学常数分别为BiOBr和CdS的5.3和9.6倍,脱除噻吩的拟一级动力学常数分别为BiOBr和CdS的1.9和3.2倍.CdS/BiOBr具有良好的光催化稳定性,循环使用5次后,降解率仍能达到90%以上.     

Ag/BiOX (X=Cl,Br, I)复合光催化剂的制备、表征及其光催化性能

采用光化学沉积法制备了一系列不同Ag含量的新型Ag/BiOX(X=Cl,Br,I)复合光催化剂,应用X射线粉末衍射(XRD)、扫描电镜(SEM)、X射线光电子能谱(XPS)、光致发光(PL)谱、紫外-可见(UV-Vis)光谱和N2物理吸附等手段对催化剂进行表征,并以420nm<λ<660nm的可见光为光源,评价了该催化剂光催化降解酸性橙II的活性,考察了不同含量的Ag沉积对BiOX样品光催化性能的影响.N2物理吸附测试结果表明,沉积银在一定程度降低了催化剂的比表面积.UV-Vis测试结果表明,Ag能产生表面等离子共振吸收,有效增强BiOCl和BiOBr对可见光的吸收能力.PL测试结果则表明,Ag能显著抑制光生电子(e-)和空穴(h+)的复合.Ag的存在大幅度提高了BiOX对染料的光催化降解活性.当负载Ag的质量分数(w)为1%-2%时,可使BiOCl、BiOBr和BiOI光催化活性分别提高了10、13和2倍.Ag/BiOX复合光催化剂具有更高催化活性的原因是复合光催化剂对可见光有很强的吸收能力,同时产生了银等离子体光催化作用和银抑制了Ag/BiOX(X=Cl,Br,I)的光生电子-空穴的复合.     

油水自组装制备Ag@AgBr/BiOBr高效可见光催化剂

采用油水自组装法制备Ag@AgBr表面修饰三维花状结构BiOBr复合光催化剂(Ag@AgBr/BiOBr),利用XRD、SEM、TEM、EDX、DRS、XPS、PL及EIS等手段对光催化剂的结构和性能进行了表征,并研究了可见光下降解亚甲基蓝(MB)的催化性能.研究表明:Ag@AgBr粒径约为20nm,均匀分散在花状微球BiOBr表面上;贵金属Ag的表面等离子体效应可显著增强可见光利用率,并有效促进光生电子空穴对的分离,Ag@AgBr(15wt%)/BiOBr光催化剂展现出最优的催化活性,可见光照射30min对MB的降解率将近90%,淬灭实验表明·O₂^-,h⁺和Br⁰均为活性物种.结合理论分析与实验结果提出复合光催化剂的降解机理.     

Fabrication of dual Z-scheme photocatalyst via coupling of BiOBr/Ag/AgCl heterojunction with P and S co-doped g-C3N4 for efficient phenol degradation

Advances in noble metal mediated Z-scheme photocatalytic system have ushered in a climax on environmental remediation. Herein, graphitic carbon nitride (GCN) and phosphorus sulphur co-doped graphitic carbon nitride (PSCN) were synthesized via calcination process. GCN, PSCN and Z-scheme visible light driven (VLD) ternary BiOBr/PSCN/Ag/AgCl nanophotocatalyst were characterized by X-ray diffraction pattern (XRD), Fourier transform infrared (FTIR), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and UV–visible diffuse reflectance spectra (UV–vis DRS). BiOBr/PSCN/Ag/AgCl nanocomposite exhibited superior visible light driven photocatalytic ability as compared to pristine PSCN, AgCl and BiOBr towards degradation of phenol. The results explicated promising photocatalytic activity along with space separation of photocarriers caused via formation of BiOBr/PSCN/Ag/AgCl Z-scheme heterojunction. The visible light absorption efficacy of BiOBr/PSCN/Ag/AgCl photocatalyst was confirmed by photoluminescence (PL) spectra. Finally, recycling experiments were explored for the mechanistic detailing of phenol photodegradation employing BiOBr/PSCN/Ag/AgCl photocatalyst. After seven successive cycles photodegradation efficacy of photocatalyst was reduced to 90% from 98%. Proposed mechanism of BiOBr/PSCN/Ag/AgCl nanophotocatalyst for degradation of phenol was discussed. OH and O₂⁻ radicals were main reactive species responsible for photocatalytic phenol degradation.     

One‐Pot Synthesis,Characterization, and Enhanced Photocatalytic Activity of a BiOBr–Graphene Composite

Herein, a chemically bonded BiOBr–graphene composite (BiOBr–RG) was prepared through a facile in situ solvothermal method in the presence of graphene oxide. Graphene oxide could be easily reduced to graphene under solvothermal conditions, and simultaneously BiOBr nanoplates with pure tetragonal phase were grown uniformly on the graphene surface. The structure and photoelectrochemical properties of the resulting materials were characterized by transmission electron microscopy (TEM), X‐ray diffraction (XRD), Fourier‐transform infrared (FTIR) spectroscopy, Raman spectroscopy, X‐ray photoelectron spectroscopy (XPS), and impedance and photocurrent action measurements. The combination of BiOBr and graphene introduces some properties of graphene into the photocatalysis reaction, such as excellent conductivity, adsorptivity, and controllability. A remarkable threefold enhancement in the degradation of rhodamine B (RhB) was observed with as‐prepared BiOBr–RG as compared with pure BiOBr under visible light (λ>420 nm). The enhanced photocatalytic activity could be attributed to the great adsorptivity of dyes, the extended photoresponse range, the negative shift in the Fermi level of BiOBr–RG, and the high migration efficiency of photoinduced electrons, which may effectively suppress the charge recombination.     

Enhanced photocatalytic performance of carbon quantum dots/BiOBr composite and mechanism investigation

Novel CQDs/BiOBr composite photocatalysts are constructed via a simple hydrothermal synthesis and show superior activity in photocatalytic degradation of organic pollutants.     

Novel Bi/BiOBr/AgBr composite microspheres: Ion exchange synthesis and photocatalytic performance

Novel Bi/BiOBr/AgBr composite microspheres were prepared by a rational in situ ion exchange reaction between Bi/BiOBr microspheres and AgNO₃. The characteristic of the as-obtained ternary microspheres was tested by X-ray diffraction (XRD), energy dispersive X-ray spectrometer (EDS), scanning electron microscope (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), UV–vis diffuse reflectance spectroscopy (UV–vis DRS) and photoluminescence (PL). Under visible light irradiation, Bi/BiOBr/AgBr microspheres exhibited an excellent photocatalytic efficiency for rhodamine B (RhB) degradation, which was about 1.4 and 4.9 times as high as that of Bi/BiOBr and BiOBr/AgBr, demonstrating that the highest separation efficiency of charge carriers in the heterostructured Bi/BiOBr/AgBr. The photocatalytic activity of Bi/BiOBr/AgBr microspheres just exhibited a slight decrease after three consecutive cycles. The photocatalytic mechanism investigation confirmed that the superoxide radicals (O₂^•−) were the dominant reactive oxygen species for RhB degradation in Bi/BiOBr/AgBr suspension.