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。     

碳量子点修饰Bi2MoO6复合电极的制备及光电催化性能研究

为改善Bi₂MoO₆电极的光吸收与表面光生载流子的迁移能力，提升其在可见光下对水体中有机物的催化降解性能，通过溶剂热、煅烧与吸附过程对Bi₂MoO₆电极进行了表面碳量子点修饰，并将其应用于光电催化系统中，通过多种物理表征与实验测试探究了CQDs修饰与光电催化偏压对改善Bi₂MoO₆催化性能的影响。结果显示，CQDs均匀分散在Bi₂MoO₆表面，2者复合作用良好，CQDs/Bi₂MoO₆复合电极具有更强的可见光利用能力与表面载流子迁移能力，其中实验制得的15-CQDs/Bi₂MoO₆电极具有最高的催化降解活性，在可见光下2 h内对亚甲基蓝的降解率最高可达82.7%，相比于Bi₂MoO₆单体电极16.0%的降解率有了明显的提升，且具有较好的循环稳定性。     

g-C3N4/Bi2MoO6复合光催化剂的制备及性能研究

结合热缩聚法和水热法制备了g-C₃N₄/Bi₂MoO₆复合光催化剂,利用X射线衍射（XRD）、傅里叶红外光谱（FT-IR）、扫描电子显微镜（SEM）、透射电子显微镜（TEM）、氮气吸附-脱附曲线、紫外-可见漫反射光谱（UV-Vis DRS）、光致发光光谱（PL）等分析测试技术对材料的结构和性能进行了表征,研究了材料光催化降解罗丹明B（RhB）的效果。结果表明,与纯Bi₂MoO₆相比,g-C₃N₄/Bi₂MoO₆复合材料提高了对可见光的吸收能力,减小了带隙宽度,在可见光激发下提高了降解RhB的光催化活性。其中,5% g-C₃N₄/Bi₂MoO₆复合材料对RhB的降解率最高,在可见光照射180 min对RhB的降解率为93%;而同样条件下Bi₂MoO₆对RhB的降解率为58%。重复性实验表明,复合材料在RhB光降解过程中是稳定的,具有较好的应用潜力。     

中空磁性微球活化过一硫酸盐降解水中甲氧苄啶的研究

采用溶剂热法制备了铁酸锰(MnFe₂O₄)中空磁性微球(HM-MnFe₂O₄),利用SEM、TEM、XRD、VSM、XPS、BET/BJH方法对材料进行表观和形貌分析,并将其应用于活化过一硫酸盐(PMS)降解水中的甲氧苄啶(Trimethoprim, TMP),通过高效液相色谱法对降解效率进行评估。结果表明,在pH为9.0、PMS浓度为3.0 mmol/L的条件下,投加0.20 g/L的HM-MnFe₂O₄纳米材料可在120 min内完全降解10.0 mg/L的TMP。同时,考察了阴阳离子对TMP降解过程的影响,Cl^-对TMP的降解有促进作用,HCO^-₃、Cu²⁺和腐殖酸(HA)均具有一定的抑制作用。通过自由基猝灭实验发现降解体系受到·OH、O^-₂·的自由基和¹O₂的非自由基影响。循...     

高活性Mn2CoO4活化PMS降解罗丹明B性能研究

通过共沉淀法制备了新型双金属混合氧化物催化剂Mn₂CoO₄。通过X-射线衍射分析、电镜-能谱分析等方法对该催化剂进行表征分析。将其用于活化过一硫酸盐(PMS)降解罗丹明B(RhB),结果表明,当Mn₂CoO₄投加量为0.25 g/L,PMS投加量为0.5 mmol/L时,反应15 min后RhB去除效率最高,去除率为99.13%,一级反应速率常数高达0.343 9 min^-1且可重复利用性能优异。淬灭实验结果表明,硫酸根自由基(SO^-₄·)在降解过程中起主要作用,羟基自由基(·OH)只有很微弱的作用,超氧自由基(·O^-₂)不参与反应。     

MWNTs/Bi2WO6-TiO2光催化降解土霉素的性能及机理

土霉素(OTC)是抗生素类废水去除的主要目标污染物之一。通过水热法合成了一种可见光响应良好的新型复合光催化剂——MWNTs/Bi₂WO₆-TiO₂,采用OTC模拟废水进行光催化降解性能及机理研究。结果表明，在反应温度为25℃时，投加0.8 g/L的MWNTs/Bi₂WO₆-TiO₂,光催化初始pH值为6、200 mL质量浓度为50 mg/L的OTC溶液120 min,降解率可达到83.97%,复合催化剂的可见光照射催化效果明显优于紫外光。复合光催化材料显示了良好的稳定性，经过4次循环使用，对OTC的降解率达72.13%,仍保持较高的光催化活性。·OH、·O^-₂是光催化降解中主要的活性物质。以上研究结果可为含抗生素的废水处理研究提供参考。     

pH值对钼酸铋及其光催化性能的影响研究

在可溶性淀粉作为模板剂的情况下,以(NH₄)₆Mo₇O₂₄·4H₂O 和Bi(NO₃)₃·5H₂O为原料,以NH₃·H₂O作为酸碱剂调节溶液的pH值,用水热法合成了Bi₂MoO₆固体光催化剂,采用测试手段对Bi₂MoO₆光催化剂进行了结构和性能表征,并用合成的Bi₂MoO₆固体光催化剂来降解罗丹明B溶液,研究其光催化性能。     

Cu/Co掺杂多孔炭活化过硫酸盐降解水中硝基酚研究

以MOF-74为模板制备了Cu/Co双金属掺杂多孔炭催化剂。用X射线衍射(XRD)、扫描电镜(SEM)、透射电镜(TEM)、N₂物理吸附/脱附等对催化剂结构进行了表征。研究并阐释了Cu/Co双金属掺杂多孔炭催化剂活化过一硫酸盐(PMS)氧化降解4-硝基酚性能及机理。结果表明，在投加100 mg·L^-1催化剂、2 g·L^-1 PMS、初始pH为6时，15 min内硝基酚(60 mg·L^-1)去除率达98%以上。降解反应符合伪一级反应动力学模型。催化剂循环反应4次，降解率均高于90%。猝灭实验及电子顺磁共振分析表明自由基(·SO₄^-、·OH、·O₂^-)和非自由基(¹O₂)均参与了降解反应。在反应过程中，Co²⁺/Co³⁺和Cu+/Cu²⁺的氧化还原循环有效活化了PMS并促进活性氧化物种的生成，从而提升了催化剂...     

Bi2Sn2O7/CeO2 Z型异质结光催化剂在可见光下降解有机污染物性能研究

利用水热法将Bi₂Sn₂O₇纳米颗粒负载到CeO₂微球上制备Z型异质结光催化剂并用于光催化降解水污染物。结果表明,在光照下60 min时,优化的Bi₂Sn₂O₇/CeO₂(BSC-5)对盐酸四环素的降解效率达到88.4%(反应速率常数k=0.033 4 min^-1),是CeO₂的8.25倍和Bi₂Sn₂O₇的4.71倍。Z型异质结可以形成更多暴露的活性中心,具有更好的光电子-空穴对分离效率、优异的氧化还原能力以及有效产生超氧自由基(·O^-₂)和羟基自由基(·OH)。此外,Bi₂Sn₂O₇/CeO₂在光催化降解实验中表现出良好的稳定性,经过5次循环后降解效率保持在85%以上。同...     

Bi2WO6光催化联合过一硫酸盐降解橙黄Ⅱ

利用简便的水热法制备Bi₂WO₆光催化材料，研究光照条件下Bi₂WO₆活化PMS降解橙黄Ⅱ溶液的效果，考察了Bi₂WO₆投加量、PMS质量浓度、初始pH、共存阴离子及腐殖酸(HA)对降解效果的影响。采用XRD、SEM和FT-IR对材料的晶体结构、表面形貌及反应前后结构进行表征分析，结果显示该材料在反应后表现出良好的稳定性。当Bi₂WO₆投加量为0.6 g/L、PMS质量浓度为0.8 g/L、橙黄Ⅱ质量浓度为10 mg/L、pH为7.5时，反应60 min内橙黄Ⅱ的降解率超过97%。实验体系在弱碱性条件下的降解效果最佳。共存离子实验结果表明，溶液中的Cl^-能促进橙黄Ⅱ降解，NO₃^-对降解的影响不明显，SO₄^2-、HCO₃^-、H₂PO_...     

Piezocatalytic performance of Fe2O3−Bi2MoO6 catalyst for dye degradation

A Fe₂O₃−Bi₂MoO₆ heterojunction was synthesized via a hydrothermal method. Scanning electron microscopy, transmission electron microscopy, energy-dispersive X-ray, powder X-ray diffraction, Fourier transform infrared spectroscopy and ultra-violet−visible near-infrared spectrometry were performed to measure the structures, morphologies and optical properties of the as-prepared samples. The various factors that affected the piezocatalytic property of composite catalyst were studied. The highest rhodamine B degradation rate of 96.6% was attained on the 3% Fe₂O₃−Bi₂MoO₆ composite catalyst under 60 min of ultrasonic vibration. The good piezocatalytic activity was ascribed to the formation of a hierarchical flower-shaped microsphere structure and the heterostructure between Fe₂O₃ and Bi₂MoO₆, which effectively separated the ultrasound-induced electron–hole pairs and suppressed their recombination. Furthermore, a potential piezoelectric catalytic dye degradation mechanism of the Fe₂O₃−Bi₂MoO₆ catalyst was proposed based on the band potential and quenching effect of radical scavengers. The results demonstrated the potential of using Fe₂O₃−Bi₂MoO₆ nanocomposites in piezocatalytic applications.     

钼酸铋半导体光催化剂的研究新进展

钼酸铋拥有典型的Aurivillius型结构,主要由(Bi_2O_2)~(2+)层及MoO_6钙钛片层状结构组成,显示出良好的光催化性能,广泛用于有机污染物的降解,成为近年来最受关注的一类可见光催化材料。综述钼酸铋半导体光催化剂的制备方法,以及通过构建异质结、掺杂、固溶体、金属沉积、量子点等改性措施提高其光催化活性,归纳和总结钼酸铋光催化剂在催化氧化反应、降解有机废水、电化学储能和CO_2的还原、气体传感器等方面的应用,并对钼酸铋光催化剂发展进行展望。     

Role of oxygen vacancies and Sr sites in SrCo0.8Fe0.2O3 perovskite on efficient activation of peroxymonosulfate towards the degradation of aqueous organic pollutants

Metal-based perovskite oxides have contributed significantly to the advanced oxidation processes (AOPs) due to their diverse active sites and excellent compositional/structural flexibility. In this study, we specially designed a perovskite oxide with abundant oxygen vacancies, SrCo_0.8Fe_0.2O₃ (SCF), and firstly applied it as a catalyst in peroxymonosulfate (PMS) activation towards organic pollutants degradation. The result revealed that the prepared SCF catalyst exhibited excellent performance on organic compounds degradation. Besides, SCF showed much better activity than La_0.5Sr_0.5Co_0.8Fe_0.2O₃ (LSCF) in terms of reaction rate and stability for the degradation of the organic compounds. Based on the analysis of scanning electron microscope, transmission electron microscope, X-ray diffraction, N₂ adsorption–desorption, X-ray photoelectron spectroscopy and electron paramagnetic resonance, it was confirmed that the perovskite catalysts with high content of Sr doping at A-site could effectively create a defect-rich surface and optimize its physicochemical properties, which was responsible for the excellent heterogeneous catalytic activity of SCF. SCF can generate three highly active species: ¹O₂, SO^-₄· and ·OH in PMS activation, revealing the degradation process of organic compounds was a coupled multiple active species in both radical and nonradical pathway. Moreover, it was mainly in a radical pathway in the degradation through PMS activation on SCF and SO^-₄· radicals produced were the dominant species in SCF/PMS system. This study demonstrated that perovskite-type catalysts could enrich OVs efficiently by doping strategy and regulate the PMS activation towards sulfate radical-based AOPs.     

3D花状Bi_2WO_6催化降解水中头孢曲松钠

近年来头孢曲松钠滥用导致严重的环境问题,寻找一种绿色环保降解抗生素的方法迫在眉睫。通过水热法,采用盐酸调控反应pH=5,成功制得3D花朵状Bi_2WO_6光催化剂。通过可见光(λ>420 nm)催化降解水中头孢曲松钠,结果表明,3D花朵状Bi_2WO_6光催化剂在240 min可降解70.18%的头孢曲松钠;对催化机理研究发现,空穴(h+)和超氧自由基(·O-2)起主要催化作用,羟基自由基(·OH)次之。制备的Bi_2WO_6光催化剂在降解水中残余抗生素类有机污染物方面具有潜在应用价值。     

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.     

Co3O4-Bi2O2CO3催化剂的制备及其光催化性能

以Bi(NO₃)₃·5H₂O、Co(CH₃COO)₂·4H₂O为原料,采用化学沉淀-水热法制备了Co₃O₄-Bi₂O₂CO₃异质结构复合半导体光催化剂,并通过X射线衍射仪（XRD）、扫描电镜（SEM）、X射线光电子能谱（XPS）、紫外可见漫反射光谱（DRS）、荧光光谱（PL）等手段对所合成的复合型催化剂进行了理化性能表征。研究结果表明：引入Co₃O₄没有改变Bi₂O₂CO₃物相结构,但促进了Bi₂O₂CO₃ 对可见光的吸收能力,提高了Bi₂O₂CO₃表面吸附氧物种的数量,抑制了光生载流子复合。复合光催化剂对罗丹明B（RhB）的光催化脱色实验显示引入Co₃O₄能够明显提高Bi₂O₂CO₃催化剂的光催化脱色能力。尤其是Co₃O₄引入量为0.6%的Co₃O₄-Bi₂O₂CO₃样品对罗丹明B染料的光催化脱色率可达到97%（模拟日光照射30min）。本文为复合型光催化剂制备提供了简单易行的技术路线,制备的新型半导体复合光催化剂Co₃O₄-Bi₂O₂CO₃在环境净化方面表现出了较好的应用前景。     

Photocatalytic activity of Cu2O/TiO2, Bi2O3/TiO2 and ZnMn2O4/TiO2 heterojunctions

Cu₂O/TiO₂, Bi₂O₃/TiO₂ and ZnMn₂O₄/TiO₂ heterojunctions were studied for potential applications in water decontamination technology and their capacity to induce an oxidation process under VIS light. UV–vis spectroscopy analysis showed that the junctions-based Cu₂O, Bi₂O₃ and ZnMn₂O₄ are able to absorb a large part of visible light (respectively, up to 650, 460 and 1000 nm). This fact was confirmed in the case of Cu₂O/TiO₂ and Bi₂O₃/TiO₂ by photocatalytic experiments performed under visible light. A part of the charge recombination that can take place when both semiconductors are excited was observed when a photocatalytic experiment was performed under UV–vis illumination. Orange II, 4-hydroxybenzoic and benzamide were used as pollutants in the experiment. Photoactivity of the junctions was found to be strongly dependent on the substrate. The different phenomena that were observed in each case are discussed.