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1.
构筑Z型异质结复合物是光催化领域解决电子-空穴对复合较快的常用方法,其独特的双光子体系能高效的提升光催化速率而备受关注。本文通过水热法原位构筑二维/二维(2D/2D)WO3/Ag:ZnIn2S4 Z型异质结复合物,并且利用透射电子显微镜(TEM)、X射线衍射(XRD)、X射线光电子能谱(XPS)、紫外-可见漫反射光谱(UV-Vis DRS)、光电化学(PEC)和荧光光谱(PL)对其微观形貌、物相结构、元素化学态和光电性能等进行表征分析,以及采用可见光(加λ>420 nm的滤光片)照射来评价2D/2D WO3/Ag:ZnIn2S4 Z型异质结复合物光解水制氢气和光降解甲基橙(MO)的催化性能。结果表明,在2D/2D WO3/Ag:ZnIn2S4 Z型异质结复合物中,随着Ag:ZnIn2S4的含量增加,光催化性能也显著增强。当Ag:ZnIn2S4的质量分数为35.0%时,复合物表现出最佳的制氢速率(158.93 μmol.g-1.h-1)与降解速率(0.18 min-1),这为基于WO3纳米片设计和构筑2D/2D Z型异质结复合物用于可见光催化制氢和污染物降解提供了新的见解。  相似文献   

2.
利用微波辅助双模板法、软模板法制备了一系列的CeO2/g-C3N4复合催化材料,通过XRD、N2吸附-脱附、XPS、SEM和TEM等方式对材料进行表征,并对其湿式催化性能进行研究。结果表明,双模板法制备的D-CeO2/g-C3N4复合材料表现出立方相CeO2和层叠g-C3N4的特征,比表面积和孔径较大,属于介孔结构,表面存在Ce3+和Ce4+,有利于氧空位的形成。加入1 g嵌段共聚物 F127,使用无水乙醇溶液为溶剂,调节混合液呈碱性,微波辐射反应120 min后得到的D-CeO2/g-C3N4(7.5)样品,结构完整均匀,具有最佳形貌特征。控制反应温度75 ℃,D-CeO2/g-C3N4(7.5)投加0.7 g,H2O2投加 0.5 mL,初始pH值为5时,100 mg/L的苯酚溶液COD去除率可达80%以上。 D-CeO2/g-C3N4(7.5) 复合催化材料使用五次以后仍可达60%以上的催化降解效果。  相似文献   

3.
电致变色广泛应用于智能窗领域,但电致变色材料仍需外部电源驱动,将太阳能电池与电致变色材料结合起来的光电致变色器件可实现无需外部供电的智能变色调控。性能优异的变色阴极和光阳极是当下光电致变色器件的研究热点。通过水热法制备WO3-MoO3薄膜,研究其电致变色性能;通过水热法结合连续离子层沉积法制备TiO2/CdS复合薄膜,研究其光电转换性能。最后将WO3-MoO3薄膜和TiO2/CdS复合薄膜分别作为光电致变色器件的变色阴极、光阳极构建WO3/MoO3-TiO2/CdS光电致变色器件。WO3/MoO3-TiO2/CdS光电致变色器件具有较大的光学调制范围(630nm处为41.99%)、更高的着色效率(35.787%),将其作为智能窗应用在现代建筑、通行工具等领域具有重要应用价值。  相似文献   

4.
在磁性膨润土(MBent)表面接枝聚乙烯亚胺(PEI)制备了聚乙烯亚胺改性磁性膨润土(PEI/KH560/MBent),采用FTIR、VSM、XRD、TGA、EA、SEM和EDS对其进行了表征,考察了其对水溶液中Pb2+和Cu2+的吸附性能。结果表明,聚乙烯亚胺已成功接枝于磁性膨润土表面,并有效提高其对Pb2+和Cu2+吸附量;溶液初始pH对吸附量影响较大,随着pH的增大,吸附量增加。在pH=5,溶液初始质量浓度为300 mg/L,PEI/KH560/MBent对Pb2+和Cu2+吸附量分别为96.21和61.08 mg/g;吸附过程符合准二级动力学模型,吸附行为符合Langmuir吸附等温模型。热力学研究表明,吸附为自发吸热过程。经过5次循环利用后,其吸附容量仍保持初始的60%以上,表明PEI/KH560/MBent具有一定的重复利用性。  相似文献   

5.
采用固相燃烧法和不同的焙烧温度制备了600、650、700和750 ℃的LiZn0.05Al0.03Mn1.92O4材料。实验结果表明,Zn-Al复合掺杂和焙烧未改变LiMn2O4的晶体结构,样品结晶性随焙烧温度的升高而增加,650 ℃及以上时形成了较多包含高暴露{111}、小面积{110}和{100}晶面的截断八面体形貌晶粒,但750 ℃时部分样品发生分解。优化焙烧温度650 ℃的样品具有优良的倍率容量和容量保持率,在5 C和10 C下,初始放电比容量和1000次循环后容量保持率分别为101.3 mAh/g、81.5%和99.9 mAh/g、74.3%。CV和EIS表明,其具有较好的循环可逆性和较大的Li+扩散系数。Zn-Al共掺和形貌调控改性LiMn2O4正极材料有效抑制了LiMn2O4材料的Jahn-Teller效应,形成的截断八面体颗粒形貌降低了Mn的溶解,同时提供了更多的Li+迁移三维通道,改善了材料的倍率容量及循环寿命。  相似文献   

6.
高效、清洁且无毒无害的催化剂是实现以甲酸(HCOOH)为化学储氢材料分解制氢的重点。本文采用水热法在453K的条件下制备TiO2载体,再通过浸渍法向其中加入总量为0.1 mmol的NiCl2.6H2O和K2PdCl4金属溶液,将活性组分Ni、Pd负载到TiO2载体上合成NiPd/TiO2催化剂,并探究其对催化甲酸分解制氢的性能的影响。探究结果表明,在光照条件下,NiPd/TiO2催化剂中,当金属Ni:Pd比例为2:8时,催化剂的反应转化频率(TOF)值最大,此时催化剂的 TOF 为3528 h-1,且该催化剂上甲酸分解的活化能(Ea)为53.9 kJ/mol。关键词:镍钯催化剂;甲酸;分解制氢;二氧化钛;光照中图分类号:TQ630 文献标识码: A 文章编号:  相似文献   

7.
利用XRD,SEM等分析手段对用后的以铝酸钙水泥和MgO-SiO2-H2O为复合结合剂的钢包矾土尖晶石浇注料进行表征,并对其抗渣侵蚀机理进行研究。分析结果表明:铝酸钙水泥及MgO-SiO2-H2O体系的复合结合剂在高温下与基质中矾土细粉、α-Al2O3等反应生成非晶态熔融相,使得基质的致密度提高,抑制了钢包渣向其内部的渗透;预合成及原位反应生成的镁铝尖晶石吸附渣中的Fe2+,导致渣中Fe2+的浓度降低,粘度提高,最终渣的成分转变为硅含量较高的CaO-SiO2-Al2O3渣;矾土原料晶界处杂质在高温下生成的非晶态熔融相迁移至基质,其富含的TiO2与CaO-SiO2-Al2O3渣中的CaO反应生成稳定的钙钛矿,降低了渣中CaO的含量,渣的粘度进一步提高,抑制了渣向矾土尖晶石浇注料内部的持续渗透和扩散。  相似文献   

8.
采用传统固相法制备了Co0.7-xMn2.1Ni0.2NdxO4(X=0,0.04,0.06,0.08)样品。利用X射线衍射、SEM、阻值测量等手段,研究了微量Nd2O3掺杂对MnCoNi系NTC热敏电阻材料的影响。研究结果表明:在0≤X≤0.08掺杂范围内,随着Nd2O3掺杂量的增加,MnCoNi系NTC热敏电阻的晶相结构和阻温特性并没有改变,晶粒变小,电阻率和B值分别由202.8Ω.cm、3432K,上升到2944.7Ω.cm、4152K;老化特性得到显著提高,△R25/ R25和△B25/50/ B25/50变化率分别由1.15%,0.75%降至0.31%,0.22%。  相似文献   

9.
微生物燃料电池(MFC)在处理含硝酸盐(NO3--N)废水时具有同时产电和脱氮的潜力,寻找成本低且改善其产电脱氮性能的阴极修饰材料是MFC在含氮废水处理领域应用的关键。氧化亚铜/还原氧化石墨烯(Cu2O/rGO)复合材料具有良好的电化学性能,在替代铂基材料提高MFC性能方面具有一定的应用前景。本研究通过还原法制备了Cu2O/rGO复合材料,并对材料的结构和氧还原性能进行表征;同时,将其负载于阴极碳布后分析其电化学性能,并通过MFC的输出电压、功率密度和NO3--N的去除率探究Cu2O/rGO阴极对MFC产电和脱氮性能的强化作用;通过对反硝化相关酶活性和胞外聚合物的测定,探究Cu2O/rGO阴极强化MFC性能的机理。结果表明:Cu2O/rGO复合材料具有大量的介孔结构,能够为电子传递提供更多的通道,并且Cu2O/rGO复合材料具有良好的氧化还原可逆性;与Pt/C阴极相比,Cu2O/rGO阴极的交换电流密度升高33.53%,电子转移阻力降低65.53%;Cu2O/rGO-MFC在处理NO3-N废水时获得的最大平均输出电压(662.54 mV)、最大功率密度(26.27 mW/cm2)、平均库伦效率(32.02%)和NO3--N去除速率(83.33 mg NO3--N L/h)均高于Pt/C-MFC(485.33 mV,16.98 mW/cm2,7.38%,41.67 mg NO3--N L/h);Cu2O/rGO复合材料通过提高MFC阴极反硝化关键酶活性和类蛋白组分含量,改善了MFC的产电和脱氮性能。  相似文献   

10.
利用可见光将CO2转化为CO和CH4有望同时解决温室效应和能源危机。Z型光催化体系能够最大限度降低光生电子-空穴对的复合,提高光催化效率。本文采用水热合成法制备了g-C3N4/WO3·H2O (CNW-1)复合材料,通过X射线衍射、X射线光电子能谱、电镜等方法进行结构表征,探究了298 K、0.1 MPa条件下其对CO2的可见光催化还原性能,并提出了可能的反应机理。通过调控三氧化钨结晶水含量可以实现CO和CH4的产量调节,在反应10 h后,CNW-1具有最高的CH4产率(0.33 μmolg-1),而CNW具有最高的CO产率(0.67 μmolg-1)。这项研究为CO2选择性还原为C1化合物提供了一种有效策略,同时也突出了以g-C3N4作为半导体构建Z型光催化体系在催化领域的应用潜力。  相似文献   

11.
A thin-film photoelectrocatalytic (PEC) reactor with slant-placed TiO2/Ti anode was developed and successfully applied to degrade Rhodamine B (RhB) and textile effluent. Using a 5–150 mg L−1 RhB solution as the model system, thin-film PEC removed total color and TOC by 99–28% and 78–15%, respectively, in 1 h, which is much higher than 82–7% and 60% to zero by conventional PEC. The enhanced treatment efficiency achieved by thin-film PEC process was attributed to the significantly reduced path length of irradiation light source. The wastewater was kept circulating during the experiments to timely refresh the aqueous film on the TiO2/Ti anode and promote the mass transfer of the target pollutants and the degradation products in the bulk solution. The thin-film PEC reactor can degrade both simulated and real dye wastewater efficiently under UV light irradiation. Results suggested that thin-film PEC was particularly superior for treating a high concentration solution. The thin-film PEC reactor was also applied to treat RhB solution efficiently under solar light irradiation. The recycle experiments demonstrated excellent stability and reliability of the slant-placed TiO2/Ti anode. This study proposed a simple and effective method to design PEC reactor applicable for industrial dye wastewater treatment.  相似文献   

12.
TiO2 particles supported on multi-walled carbon nanotubes (MWCNTs) were prepared using a sol–gel method to investigate their photocatalytic activity under simulated solar irradiation for the degradation of methyl orange (MO) in aqueous solution. The prepared composites were analyzed using XRD, SEM, EDS and UV–vis absorption spectroscopy. The results of this study indicated that there was little difference in the shape and structure of MWCNTs/TiO2 composite and pure TiO2 particles. The composite exhibited enhanced absorption properties in the visible light range compared to pure TiO2. The degradation of MO by MWCNTs/TiO2 composite photocatalysts was investigated under irradiation with simulated solar light. The results of this study indicated that MWCNTs played a significant role in improving photocatalytic performance. Different amounts of MWCNTs had different effects on photodegradation efficiency, and the most efficient MO photodegradation was observed for a 2% MWCNT/TiO2 mass ratio. Photocatalytic reaction kinetics were described using the Langmuir–Hinshelwood (L–H) model. The photocatalyst was reused for eight cycles, and it retained over 95.2% photocatalytic degradation efficiency. Possible decomposition mechanisms were also discussed. The results of this study indicated that photocatalytic reactions with TiO2 particles supported on MWCNTs under simulated solar light irradiation are feasible and effective for degrading organic dye pollutants.  相似文献   

13.
A two-step method, combining with sol–gel and mechanical alloying (MA) method, was used to fabricate the tungsten and nitrogen co-doped TiO2 nano-powders ((W, N) co-doped TiO2 NPs). The (W, N) co-doped TiO2 NPs showed strong absorbance in visible range, as long as 650 nm. Enhanced photocatalytic activities under visible light irradiation were also observed from the results of photodegradation experiments and chemical oxygen demand (COD) analysis. Physical, chemical, and optical properties of the samples were investigated. Possible reasons for the enhanced photocatalytic activities were analyzed based on the experimental results. Oxygen vacancies detected by electron spin response (ESR) spectra, acting as trapping agencies for electrons (e) to produce active oxygen species (O2−), were proved to be the main cause for the improved photocatalytic performances.  相似文献   

14.
FeTiO3/TiO2, a new heterojunction-type photocatalyst working at visible light, was prepared by a simple sol–gel method. Not only did FeTiO3/TiO2 exhibit greatly enhanced photocatalytic activity in decomposing 2-propanol in gas phase and 4-chlorophenol in aqueous solution, but also it induced efficient mineralization of 2-propanol under visible light irradiation (λ ≥ 420 nm). Furthermore, it showed a good photochemical stability in repeated photocatalytic applications. FeTiO3 showed a profound absorption over the entire visible range, and its valence band (VB) position is close to that of TiO2. The unusually high photocatalytic efficiency of the FeTiO3/TiO2 composite was therefore deduced to be caused by hole transfer between the VB of FeTiO3 and TiO2.  相似文献   

15.
TiO2 photocatalyst loaded on Si3N4 (TiO2/Si3N4) was prepared by a conventional impregnation method and its photocatalytic performance for the degradation of organics (2-propanol) diluted in water was compared with that of TiO2 photocatalysts (TiO2/SiO2, TiO2/Al2O3, and TiO2/SiC) loaded on various types of supports (SiO2, Al2O3, and SiC). The formation of the well-crystallized anatase phase of TiO2 was observed on the calcined TiO2/Si3N4 photocatalyst, while a small anatase phase of TiO2 was observed on the TiO2/SiC photocatalyst and amorphous TiO2 species was the main component on the TiO2/SiO2 and TiO2/Al2O3 photocatalysts. The measurements of the water adsorption ability of photocatalysts indicated that the TiO2/Si3N4 photocatalyst exhibited more hydrophobic surface properties in comparison to other support photocatalysts. Under UV-light irradiation, the TiO2/Si3N4 photocatalyst decomposed 2-propanol diluted in water into acetone, CO2, and H2O, and finally, acetone was also decomposed into CO2 and H2O. The TiO2/Si3N4 photocatalyst showed higher photocatalytic activity than TiO2 photocatalyst loaded on other supports. The well-crystallized TiO2 phase deposited on Si3N4 and the hydrophobic surface of Si3N4 support are important factors for the enhancement of photocatalytic activity for the degradation of organic compounds in liquid-phase reactions.  相似文献   

16.
对静电纺丝法制备的TiO2和TiO2-V2O5纳米纤维进行光催化脱除模拟烟气中Hg0的研究。对纳米纤维进行了SEM、TEM、XRD、BET和UV-Vis检测。结果表明TiO2-V2O5纳米纤维为锐钛矿,V2O5高度分散在TiO2中。纤维直径在200 nm左右,由粒径为10 nm左右的微粒组成。掺杂V2O5后,纤维的吸光范围扩大,在可见光范围内的吸光度比纯TiO2时有了很大提高。实验研究了不同光照条件、V2O5的掺杂量和循环次数对脱汞的影响,分析了TiO2-V2O5催化脱汞的机理。当V2O5的质量含量为3%时,TiO2-V2O5在可见光下的脱汞率可达到66%,比纯TiO2时的7%有了显著提高;纤维的脱汞性能稳定,多次循环后紫外光和可见光下的脱汞率仍分别保持在80%和65%左右。电子的跃迁和电子、空穴的快速分离是TiO2-V2O5在可见光下脱汞率提高的主要原因。  相似文献   

17.
Visible-light-induced BiVO4 photocatalyst has been successfully synthesized via a solution combustion synthesis (SCS) method. The photocatalytic activities of the as-synthesized sample were evaluated by the photodegradation of rhodamine B (RhB) and phenol under visible-light irradiation (λ > 420 nm). The decolorization of high-concentrated RhB (10− 4 M) and the variation of the chemical oxygen demand (COD), demonstrated that the BiVO4 photocatalyst was efficient in aromatic organic compounds degradation. The reduction of total organic carbon (TOC) (about 22.0% after 4.5 h of irradiation) showed that the mineralization of RhB over the BiVO4 photocatalyst is realized. Additionally, much enhanced photocatalytic performance for phenol degradation was also realized with the assistance of appropriate amount of H2O2.  相似文献   

18.
Asymmetric TiO2 hybrid photocatalytic ceramic membranes with porosity gradient have been fabricated via acid-catalyzed sol–gel method. Different structure directing agents (SDAs) i.e. Pluronic P-123, Triton X-100, Tween 20 and Tween 80 were incorporated in the preparation of TiO2 sol to obtain a porous multilayered TiO2 coated on the alumina ceramic support. Six different SDA-modified membrane specimens were fabricated. Four of which were coated with the TiO2 sols prepared using only one type of SDA. The remaining two specimens were fabricated via multilayer coating of different TiO2 sols prepared using different types of SDAs. Physico-chemical and morphological properties of different TiO2 layers were thoroughly investigated. The membrane M1 which had the most porous TiO2 sub-layers showed a high pure water permeability of 155 L m−2 h−1 bar−1. The membrane showed a relatively high Rhodamine B (RhB) removal of 2997 mg m−2 over 8 h treatment duration in the batch photoreactor, second only to the Pluronic-based TiO2 membrane (specific RhB removal of 3050 mg m−2). All membrane specimens exhibited good performances while operated in the flow-through photocatalytic membrane reactor. Over 91% of RhB removal capability was retained after 4 treatment cycles. All membranes also showed self-cleaning property by retaining >90% of initial flux after 4 treatment cycles. The flexibility of optimizing membrane performances by fine-tuning the porosity gradient configuration of the photocatalytic layer has also been demonstrated.  相似文献   

19.
A visible light active binary SnO2-TiO2 composite was successfully prepared by a sol-gel method and deposited on Ti sheet as a photoanode to degrade orange II dye. Titanium and SnO2 can promote the development of rutile phase of TiO2 and inhibit the formation of anatase phase of TiO2. Formation of SnO2 crystalline is insignificant even when the calcination temperature increases to 700 °C. Heterogenized interface between SnO2 and TiO2 inhibits growth of TiO2 linkage and leads to the particle-filled surface morphology of SnO2-containing films. The carbonaceous, Ti-O-C bonds and Ti3+ species are likely to account for the photoabsorption and photoelectrocatalytic (PEC) activity under visible light illumination. The electrode with 30% SnO2 exhibits higher photocurrent when compared with those in the region of 0-50%. The 600 °C-calcined SnO2-TiO2 electrode indicates higher activity when compared with those at 400, 500, 700 and 800 °C. PEC degradation of orange II follows the Langmuir-Hinshelwood model and takes place much effectively in a solution of pH 3.0 than those in pH 7.0 and pH 11.0.  相似文献   

20.
Delafossite-structured oxides AgMO2 (M = Al, Ga, In) were successfully synthesized using fluoro(ethylene-propylene) (FEP) pouch via a facile hydrothermal method. The obtained samples were characterized by X-ray diffraction (XRD), BET surface area measurement, UV–vis diffuse reflectance spectroscopy (DRS), scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS). The photocatalytic activity of the as-prepared samples was evaluated by the degradation of rhodamine B (RhB) and methyl orange (MO) under visible light irradiation. All three samples showed photocatalytic activity for RhB and MO degradation under visible light irradiations and their photocatalytic activity followed the order of AgInO2 > AgGaO2 > AgAlO2. The relative high photocatalytic activity of AgInO2 can be attributed to its high quantity of the surface hydroxyl groups. The photocatalytic mechanism of AgInO2 was proposed and its stability was also investigated.  相似文献   

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