Ag/Bi2 WO6的制备及光催化氧化性能

以Bi（NO3）3·5H2O、 Na2WO4·2H2O、 AgNO3为原料,利用液相沉淀法制备Bi2WO6及Ag掺杂Bi2WO6光催化剂,以亚甲基蓝溶液为目标降解物,对其降解效率进行研究。研究结果表明,当亚甲基蓝溶液的浓度为15 mg/L,体积为50 mL,降解时间3.5 h, Bi2 WO6降解率仅为55%;当Ag/Bi摩尔比为0.4%时, Ag/Bi2 WO6表现出较好的催化性能,相同时间降解率达到97%。     

前驱体对熔盐法合成Bi2WO6光催化剂及其性能的影响

分别以Bi(NO3)3和Na2WO4溶液直接混合所得沉淀、加氨水所得沉淀及Bi(NO3)3×5H2O+Na2WO4×2H2O为前驱体,采用熔盐法合成Bi2WO6光催化剂粉体,研究了不同前驱体所制粉体的物相、形貌,以其为催化剂,在可见光照射下降解罗丹明B溶液. 结果表明,用后二者为前驱体均可得到薄片状纯相Bi2WO6粉体. 加氨水所得沉淀为前驱体所制Bi2WO6粉体的光催化性能最好,在可见光照射下对0.01 mmol/L RhB溶液的降解率在60 min内达99%.     

掺杂型Bi2WO6光催化剂的制备及其光催化性能研究

复合氧化物Bi2WO6可作为一种高效的光催化材料,但Bi2WO6的光生电子空穴对复合率高,分离困难,导致对光的吸收能力下降,光催化效率降低。金属Cu和Ag是良好的光催化剂助剂,能有效降低光催化剂的光生电子空穴对复合率,改善催化剂的光吸收性能。采用水热法制备金属Cu和Ag掺杂的可见光催化剂Bi2WO6,并进行X射线衍射、扫描电子显微镜、紫外-可见光谱和比表面积表征。结果表明,掺杂的金属离子并未进入Bi2WO6晶格内部,只是负载于Bi2WO6表面。掺杂金属后,Bi2WO6的吸收边带变宽,吸光强度变强,比表面积显著增加。以模拟含酚废水为处理对象,考察掺杂型Bi2WO6对苯酚光催化降解效果的影响。实验结果表明,Cu-Bi2WO6光催化剂在光照作用下对苯酚有降解作用,随着光照时间的延长,苯酚的降解程度不断提高,在空气通入量为25 mL·min-1和400 W金卤灯下光照180 min,Cu-Bi2WO6和Ag-Bi2WO6对10 mg·L-1的模拟含酚废水基本降解完成。     

Bi_2WO_6光催化剂的研究进展

Bi2WO6是一种非常有潜力的光催化剂。通过掺杂、负载改性,可提高电荷分离效率和延伸光激发的能级范围,能有效吸收太阳光,可作为光解水和降解有机污染物的催化剂。对Bi2WO6的晶体结构和能带结构进行了分析,综述了其制备方法、形貌尺寸、修饰改性以及光催化性能,最后分析了Bi2WO6的催化原理并对今后的研究方向进行了展望。     

花簇状g-C3N4/Bi2MoO6微球的制备及光催化降解模拟染料废水

以酵母为生物模板，通过水热-牺牲模板法制备得到了花簇状g-C3N4/Bi2MoO6复合微球，利用XRD、SEM、TEM、FT-IR、DRS、光电流响应以及氮气吸附-脱附等手段对样品的晶体结构、微观形貌、光吸收和比表面积等性能进行表征，并对样品可见光催化降解亚甲基蓝（MB）模拟染料废水的性能和机理进行探讨。实验结果表明：水热-牺牲模板法可实现g-C3N4与Bi2MoO6在生物模板表面的成功复合，样品分散性良好，微球直径约为8μm，表面呈花簇状，比表面积达11.6007m2/g。在可见光下复合微球对亚甲基蓝模拟染料废水表现出较高的光催化降解活性，当催化剂添加量为1g/L，可见光照射120min后，初始浓度为15mg/L的亚甲基蓝废水降解率高达96%以上。机理分析证实花簇状复合微米球表面g-C3N4与Bi2MoO6形成的Z型异质结有效降低了电子-空穴的复合率，显著提升了对模拟染料废水的可见光催化性能。     

WO3/C/Ag3PO4复合材料光催化降解双酚A

以磷酸法制备的活性炭、WO3、AgNO3、Na2HPO4为原料,采用共沉淀法制备WO3/C/Ag3PO4复合材料。采用X 射线衍射（XRD）、傅里叶红外光谱（FT-IR）、光电子能谱（XPS）、扫描电镜（SEM）、透射电镜（TEM）和固体紫外漫反射（UV-DRS）技术对其进行表征。结果表明,Ag3PO4与WO3之间形成异质结。在可见光照射下,以双酚A(BPA)模拟污染物,评价WO3/C/Ag3PO4复合材料的光催化降解性能,并提出 WO3/ C/Ag3PO4 复合材料对BPA的光降解机理。结果表明,在一系列光催化剂中, 23% WO3/ 7% C/ Ag3PO4 复合材料在可见光下对10 mg/L BPA水溶液的降解率在90 min分钟达到95%,明显高于单一的Ag3PO4和WO3。经过3次循环重复,BPA的降解率仍能保持在74%,表明WO3/C/Ag3PO4光催化剂具有良好的稳定性。光催化机理表明,自由基?O- 2和h 在降解过程中起主要作用。     

Preparation, characterization and photocatalytic behavior of WO3-fullerene/TiO2 catalysts under visible light

WO3-treated fullerene/TiO2 composites (WO3-fullerene/TiO2) were prepared using a sol-gel method. The composite obtained was characterized by BET surface area measurements, X-ray diffraction, scanning electron microscopy, energy dispersive X-ray analysis, transmission electron microscopy, and UV-vis analysis. A methyl orange (MO) solution under visible light irradiation was used to determine the photocatalytic activity. Excellent photocatalytic degradation of a MO solution was observed using the WO3-fullerene, fullerene-TiO2, and WO3-fullerene/TiO2 composites under visible light. An increase in photocatalytic activity was observed, and WO3-fullerene/TiO2 has the best photocatalytic activity; it may attribute to the increase of the photo-absorption effect by the fullerene and the cooperative effect of the WO3.     

WO3/BiOCl0.7I0.3光催化剂的制备及其光催化降解机理

通过简单的煅烧法和原位沉淀法制备了WO₃/BiOCl_0.7I_0.3复合光催化材料,利用X射线衍射(XRD)、扫描电子显微镜(SEM)、X射线能谱(XPS)、紫外可见漫反射光谱(UV-Vis DRS)等表征手段对合成材料的微观形貌、化学组成等进行表征。并通过可见光催化降解20mg/L盐酸四环素来评价材料的光催化性能,结果显示,WO₃/BiOCl_0.7I_0.3复合材料较单一的BiOCl_0.7I_0.3和WO₃具有更优的光催化性能,其中W与Bi摩尔比为1∶15时,复合材料具有最高的光降解率,可见光下60min达到最高值93.84%,且四次循环试验后仍具有较好的光催化活性。对自由基捕获试验结果及电子自旋共振光谱进行分析,明确了h⁺和·O₂^-为光催化主要活性物质,提出WO₃/BiOCl_0.7I<...     

低温固相反应合成Bi2WO6粉体及其可见光光催化性能

以Bi(NO3)3?5H2O和Na2WO4?2H2O为原料,采用固相法直接合成Bi2WO6粉体,研究了反应温度和保温时间对产物物相、形貌及可见光光催化性能的影响. 结果表明,350℃下保温2 h所得粉体含少量Bi2O3和Na2W4O13杂质,但光催化性能最好,可见光照射90 min对0.01 mmol/L RhB溶液的降解率达95%,且经5次循环后光催化活性和化学稳定性良好.     

ZnO/碳纳米管复合光催化材料对抗生素的光催化降解

采用溶胶法合成了ZnO/碳纳米管复合光催化材料,采用X射线衍射仪(XRD)、扫描电子显微镜(SEM)、紫外-可见漫反射吸收光谱(UV-Vis)等手段对复合催化剂进行了表征。以氙灯(250～800 nm)为光源,盐酸四环素为降解对象,评价样品的光催化活性。比较ZnO/CNTs复合材料和纯ZnO对抗生素的降解能力,并考察光催化剂的重复利用能力。结果表明,通过溶胶法得到了在碳纳米管表面均匀、致密包覆ZnO颗粒的复合材料。由于ZnO/CNTs材料良好的吸附性能,其光催化活性高于纯ZnO,在300 W氙灯光源下反应2 h,对盐酸四环素的降解率达82.38%,同时复合材料显示了抑制ZnO光蚀的能力。     

Z型Ag2CO3/BiOCl异质结光催化剂的制备及其可见光催化机理分析

通过溶剂热法制备BiOCl纳米片,共沉淀法制备Ag_(2)CO_(3)和复合催化剂Ag_(2)CO_(3)/BiOCl,研究各材料可见光催化降解罗丹明B的效果,确定Ag_(2)CO_(3)与BiOCl的最佳配比,并通过表征分析复合材料的结构和异质结光催化降解机理。结果表明,当Ag_(2)CO_(3)与BiOCl的质量比为50%时,Ag_(2)CO_(3)/BiOCl异质结催化剂的可见光催化效率最高,其一级动力学反应速率常数是BiOCl和Ag_(2)CO_(3)的6.79和12.58倍。紫外可见漫反射分析证明,Ag_(2)CO_(3)的加入使Ag_(2)CO_(3)/BiOCl对可见光的吸收增加,拓宽了光响应范围。XPS价带谱证明,调控后的BiOCl纳米片能带位置上移。通过自由基捕获实验和电子顺磁共振(ESR)证明,其主要活性物种是·O^(-)_(2)、h^(+)和·OH,从而推断Ag_(2)CO_(3)与BiOCl构成Z型异质结,相比Ⅱ型异质结拥有较高的氧化还原能力,可充分利用水中的溶解氧(O_(2))和OH^(-),大大提升了光催化效率。     

Construction of defect-containing UiO-66/MoSe2 heterojunctions with superior photocatalytic performance for wastewater treatment and mechanism insight

Metal–organic frameworks are recognized as promising multifunctional materials, especially metal–organic framework-based photocatalysts, which are considered to be ideal photocatalytic materials. Herein, a new type of UiO-66/MoSe₂ composite was prepared using the solvothermal method. The optimum composite was selected by adjusting the mass ratio of UiO-66 and MoSe₂. X-ray diffraction analysis showed that the mass ratio influenced the crystal plane exposure rate of the composite, which may have affected its photocatalytic performance. The composite is composed of ultra-thin flower-like MoSe₂ that wrapped around cubic UiO-66, a structure that increases the abundance of active sites for reactions and is more conducive to the separation of carriers. The photocatalytic properties of the composite were evaluated by measuring the degradation rate of Rhodamine B and the catalyst’s ability to reduce Cr(VI)-containing wastewater under visible light irradiation. Rhodamine B was decolorized completely in 120 min, and most of the Cr(VI) was reduced within 150 min. The photochemical mechanism of the complex was studied in detail. The existence of Mo⁶⁺ and oxygen vacancies, in addition to the Z-type heterojunction promote the separation of electrons and holes, which enhances the photocatalytic effect.     

有机酸介导合成WO3/g-C3N4及其光催化性能

采用水热法制备了WO3/g-C3N4复合物,并探讨了草酸、柠檬酸、乙酸和水杨酸对复合物结构、形貌及催化活性的影响。结果表明,复合物中棒状WO3分布在片层状的g-C3N4上,二者结合紧密形成异质结构。以1 mol/L草酸为介导剂制备的WO3/g-C3N4的光催化活性最佳,当WO3和g-C3N4质量比为1∶1时,可见光下反应210 min,对罗丹明B的降解率达97.46%。自由基捕获实验表明,光催化反应活性基团排序为·O2->h+>·OH。经推测,光催化降解机制符合Z型机制。     

Ag3PO4/AgI光催化剂的制备及降解2-氨基-4-乙酰氨基苯甲醚机理

研究了Ag₃PO₄复合棒状AgI光催化剂的制备及降解2-氨基-4-乙酰氨基苯甲醚（AMA）的性能和机理,利用X射线衍射（XRD）、扫描电镜（SEM）、紫外可见漫反射（UV-Vis）、光电子能谱（XPS）等方法对合成样品的物相组成和形貌结构进行了表征。通过可见光催化降解AMA来评价光催化剂的催化性能。实验结果显示,Ag₃PO₄/AgI复合光催化剂比Ag₃PO₄和AgI单体具有更强的光催化氧化与还原能力,其中以I和P的比例为1∶5时效果最佳,且在五次循环使用之后仍有较好的光催化活性。自由基捕获实验证明光催化过程中光生空穴（h⁺）是主要的活性物种。投加量为30mg、光照时间60min的条件下可将AMA几乎完全去除。本文研究结果为构筑新型可见光光催化剂提供了新视角,为促进光催化降解有机污染物提供了新途径。     

Generation of hydrogen under visible light irradiation with enhanced photocatalytic activity of Bi2WO6/Cu1.8Se for organic pollutants under Vis‐NIR light reign

To make better use of solar light, a new Bi₂WO₆/Cu_1.8Se photocatalyst active to visible and near‐infrared light has been synthesized by a facile hydrothermal method. The composites were characterized by X‐ray diffractometry (XRD), scanning electron microscopy (SEM), UV‐vis diffuse reflectance spectroscopy (DRS), and photoluminescene (PL). The photocatalytic activities of Bi₂WO₆/Cu_1.8Se are evaluated by degrading Congo red solution and hydrogen generation from water. It was found that the molar percentage of Cu_1.8Se had great effects on the morphology and photocatalytic property of the Bi₂WO₆/Cu_1.8Se heterojunctions, and the composite with suitable molar amount of Cu_1.8Se exhibits much enhanced photocatalytic activity for Congo red degradation under visible and near‐infrared light irradiation and for hydrogen generation under visible light compared to Bi₂WO₆. The significant improvement photocatalytic activity of the composite could be attributed to its good light absorption, suitable band gap structure, and effective separation of photogenerated electron‐hole pairs of Bi₂WO₆/Cu_1.8Se heterojunction. This work presents an efficient multifunction photocatalyst owning the activity both for water splitting under visible light and for organic contaminants decomposition under visible‐near‐infrared light.     

Ternary Ni2P/Bi2MoO6/g-C3N4 composite with Z-scheme electron transfer path for enhanced removal broad-spectrum antibiotics by the synergistic effect of adsorption and photocatalysis

Constructing the stable, low-cost, efficient, and highly adaptable visible light-driven photocatalyst to implement the synergistic effect of photocatalysis and adsorption has been excavated a promising strategy to deal with antibiotic pollution in water bodies. Herein, a novel 3D ternary Z-scheme heterojunction photocatalyst Ni₂P/Bi₂MoO₆/g-C₃N₄ (Ni₂P/BMO/CN) was fabricated by a simple solvothermal method in which the broad spectrum antibiotics (mainly tetracyclines and supplemented by quinolones) were used as target pollution sources to evaluate its adsorption and photocatalytic performance. Notably, the Z-scheme composite significantly exhibit the enhancement for degradation efficiency of tetracycline and other antibiotic by using Ni₂P nanoparticles as electron conductor. Active species capture experiment and electron spin resonance (ESR) technology reveal the mechanism of Z-scheme Ni₂P/BMO/CN photocatalytic reaction in detail. In addition, based on the identification of intermediates by liquid chromatography–mass spectroscopy (LC–MS), the possible photocatalytic degradation pathways of TC were proposed.     

Bi2MoO6@CQDs/TiO2纳米管阵列的制备与光电催化性能

为提高TiO₂的可见光光电催化活性,本文用Bi₂MoO₆和碳量子点(CQDs)对TiO₂纳米管阵列(TNA)进行了改性。以CQDs、Bi(NO₃)₃·5H₂O和Na₂MoO₄为原料,通过简单的溶剂热法,在TNA中沉积了CQDs和Bi₂MoO₆,成功制备了新型Bi₂MoO₆@CQDs/TNA。扫描电镜(SEM)和元素mapping分析结果表明,CQDs和Bi₂MoO₆成功涂覆在TNA管壁上。通过在可见光下降解甲基橙(MO)溶液,评价了所制备的光催化剂的光电催化性能。结果显示,经3 h的光电催化降解,Bi₂MoO₆@CQDs/TNA对MO的去除率比Bi₂MoO₆/TNA高32%。CQDs优异的上转换光致发光(UCPL)性能促进了TiO₂在可见光下被激发产生光生载流子,同时Bi₂MoO₆与TiO₂的耦合抑制了光生载流子的复合,从而提高了Bi₂MoO₆@CQDs/TNA的光电催化活性。     

Photocatalytic Degradation of Tetracycline by Z-Scheme Bi2WO6/ZIF-8

To improve the photocatalytic activity of Bi₂WO₆, ZIF-8 was successfully introduced with the in-situ growth for the first time. The addition of ZIF-8 effectively inhibited the recombination of photogenerated electron–hole pairs with further improved electron utilization efficiency. The superoxide anion, .O₂^?, generated, greatly improved the photocatalytic activity. The performance of Bi₂WO₆/ZIF-8 in the photodegradation of tetracycline (TC) was studied under different conditions, including the proportions of ZIF-8, the dosage of catalyst, and the concentration of TC. The results indicated that 10 mg of B/Z/5/1 offered the best photocatalytic activity under UV light, achieving 97.8% degradation of TC (20 mg/L) within 80 min. The measured rate constant (k) for TC degradation was almost 3 times that of pure Bi₂WO₆. The effects of pH, HA, and inorganic anions on the degradation of TC were also studied for the simulated real water. Further, B/Z/5/1 could be reutilized up to five cycles without reduction of the catalysis performance. Therefore, the Bi₂WO₆/ZIF-8 heterojunction composite material can be utilized as an efficient photocatalyst for remediation of environmental pollution.

     

具有高效可见光活性的AgCl/AgVO_3异质结光催化剂的原位合成

以水热法合成的AgVO_3为前驱体,在其表面通过原位离子交换法合成AgCl/AgVO_3异质结光催化剂,利用XRD、SEM和UV-Vis等对其结构、形貌和光吸收性能进行表征,并以酸性橙-Ⅱ模拟环境中染料污染物,考察了AgCl/AgVO_3异质结的可见光催化性能。结果表明,AgCl/AgVO_3异质结光催化剂具有高效的可见光催化活性,在可见光照射下15 min,酸性橙-Ⅱ降解率达到80%,循环使用4次后,降解率仍能保持60%。自由基捕获实验结果表明,h~+和·O_2~-为光催化反应中的主要活性物种。光催化性能的提高主要归因于AgCl/AgVO_3异质结构的形成,这利于光生电子-空穴对转移和分离。最后探讨了增强AgCl/AgVO_3光催化性能的可能机理。     

WO3/Bi2WO6复合薄膜的制备及其光电化学性能

以导电玻璃为基底采用水热法制备了WO3纳米片薄膜,再通过溶剂热法改变不同溶剂热反应时间(6、8和10 h)在WO3纳米片薄膜上生长Bi2WO6制备了WO3/Bi2WO6复合薄膜.利用XRD、SEM、UV-Vis、光电流、光电催化和交流阻抗对WO3/Bi2WO6复合薄膜的结构和光电性能进行表征与测定.结果表明,WO3纳米片薄膜的光电流密度为0.74 mA/cm2,对质量浓度为6.0 mg/L亚甲基蓝的光电催化效率为47.9％.不同WO3/Bi2WO6复合薄膜的光电化学性能均优于单一WO3纳米薄膜,且溶剂热反应时间为8 h的WO3/Bi2WO6复合薄膜具有最高的光电流密度(1.22 mA/cm2)和最优的光电催化效率(58.6％).WO3/Bi2WO6复合薄膜有效降低了复合薄膜内部电子阻抗,增加了有效光电化学反应位点,显著提升了光电化学性能.