Fe~(3+)-CdS/TiO_2复合半导体光催化剂的制备与表征

采用溶胶-凝胶法制备了系列不同配比的Fe3+-CdS/TiO2光催化材料,用TEM、EDS、XRD、UV-vis等技术对其形貌、结构和光吸收特性进行了表征。以亚甲基蓝(MB)的脱色降解为模型反应,考察了光源、煅烧温度、煅烧时间、掺杂Fe3+和CdS对催化剂催化性能的影响。结果表明,Fe3+掺杂和CdS半导体复合相结合的技术,可以使TiO2对光的响应拓展到整个紫外-可见光区;当n(Fe3+)∶n(CdS)∶n(TiO2)=0.005∶1∶1、煅烧温度为300℃、煅烧时间为1 h、光源为太阳光时,Fe3+-CdS/TiO2的光催化活性最高,在1 h内可以使亚甲基蓝(MB)溶液的降解率达98.62%。     

高炉渣纤维负载TiO2光催化材料的制备及其光催化性能

以高炉渣纤维(BFSF)为载体,采用溶胶凝胶法,在BFSF表面负载TiO2,制备BFSF负载TiO2(TiO2/BFSF)光催化材料.利用差热-热重(TG-DTA)、X射线衍射仪(XRD)、场发射扫描电镜(SEM)及能谱元素分析(EDS)等近代测试方法对TiO2/BFSF的显微结构和相组成进行了表征.以模拟印染废水的亚甲基蓝(MB)的降解,评价样品的光催化活性.实验结果表明:TiO2溶胶负载3次,煅烧温度为450℃时,TiO2/BFSF光催化材料表面负载了一层均匀密实的锐钛矿型TiO2,当紫外光照射180 min时,亚甲基蓝的降解率达到92.5％.循环利用TiO2/BFSF光催化材料4次,亚甲基蓝的降解率依然能够达到63％.     

Fe3+-CdS/TiO2复合半导体的光催化性能

采用溶胶-凝胶法制备了一系列不同配比的Fe3 -CdS/TiO2光催化材料,利用UV-Vis对其光谱特性进行了表征,以亚甲基蓝(MB)的脱色降解为模型反应,考察了Fe3 、CdS/TiO2的制备条件对光催化性能的影响。     

Fe^3＋-CdS/TiO2复合半导体的光催化性能

采用溶胶-凝胶法制备了一系列不同配比的Fe^3＋-CdS/TiO2光催化材料,利用UV-Vis对其光谱特性进行了表征,以亚甲基蓝（MB）的脱色降解为模型反应,考察了Fe^3＋、CdS/TiO2的制备条件对光催化性能的影响。     

载Ag-TiO2/浮石光催化性能及耐用性考察

采用天然浮石作为TiO2的载体,以溶胶-凝胶法制备TiO2/浮石,并将银沉积在TiO2表面制得载Ag-TiO2/浮石光催化剂.利用XRD、SEM进行表征,考察了载Ag-TiO2/浮石的光催化性能及其耐用性能.结果表明,载Ag-TiO2浮石对质量浓度为10mg/L的亚甲基蓝溶液具有良好的光催化降解效果,30min时降解率...     

利用Sol-Gel法与水热合成法制备纳米TiO2及其光催化活性研究

以Sol-Gel法及水热合成方法制备了纳米TiO2,利用XRD进行了表征,以太阳光为光源,通过对亚甲基蓝溶液的降解反应,考察了两种方法所得样品的光催化活性。结果表明,利用水热合成法制备的锐钛矿型TiO2具有更小的粒径,而通过溶胶-凝胶制得的样品为混晶型TiO2,对亚甲基蓝降解具有较高的光催化活性。     

纳米TiO2/SO42-的合成及光催化降解性能研究

研究了以工业级钛酸异丙酯为前驱体,正丙醇为溶剂,浓硫酸作催化剂和抑制剂,乙酰丙酮为稳定剂,采用溶胶-凝胶法制备纳米TiO2/SO42-。利用XRD、SEM、FT-IR、UV-vis、N2吸附-脱附测定BET表面积对所制备的材料进行了表征。结果表明:纳米TiO2/SO42-催化剂在可见光区的吸收较强,所制备的催化剂与未经改性的TiO2相比,吸收边从350 nm红移到430 nm左右,其红移效果显著。在紫外灯照射下进行了光催化降解亚甲基蓝溶液的催化剂性能研究,探讨了pH值、反应温度、亚甲基蓝初始质量浓度以及催化剂用量对降解率的影响。结果表明:光催化降解亚甲基蓝在中性条件下的降解率较高,碱性环境下达到最佳;最佳反应温度为35~55℃;初始浓度越大降解率越小;处理30 mL亚甲基蓝溶液所需催化剂为30 mg。     

LDO负载纳米二氧化钛复合物的制备及其光催化性能研究

以碳酸根型镁铝层状双氢氧化物(LDH)为载体,采用溶胶-凝胶法利用酞酸丁酯水解负载纳米TiO2于LDH片层获得TiO2/LDH前驱体,通过低温焙烧前驱体获得纳米二氧化钛/层状双金属氧化物复合物(TiO2/LDO).以亚甲基蓝溶液模拟染料污染物,在波长291 nm紫外光条件下测定吸光度,评价了光催化剂不同投加量,体系pH值以及光照时间条件下对亚甲基蓝降解率的影响,研究了TiO2/LDO的光催化性能.结果表明:通过溶胶-凝胶法可以获得高分散纳米级(<10 nm)TiO2负载型TiO2/LDH复合物,TiO2/LDH中TiO2负载率达8.01wt%(质量分数);TiO2/LDO的光催化性能较纯LDO高,TiO2负载于LDO层板对亚甲基蓝具有协同催化作用;在pH值为9的80 mL亚甲基蓝溶液(浓度为5 mg/L)中投入0.20 g TiO2/LDO,催化反应8 h后降解率高达81.7%,TiO2/LDO对亚甲基蓝溶液的光催化反应符合一级动力学方程.     

漂浮型纳米TiO2/EP的制备及其光催化性能

以膨胀珍珠岩为载体,钛酸四丁酯为原料,用溶胶-凝胶法制备漂浮型纳米TiO2光催化剂,并用该光催化剂在太阳光下对亚甲基蓝进行光催化降解实验.结果表明,在450℃焙烧2h,负载3次的条件下制备的漂浮型催化剂光催化活性较好.150 mg漂浮型纳米TiO2/EP在30 mL亚甲基蓝溶液(4 mg/L)液面平铺,经120 min太阳光照射,亚甲基蓝的降解率为97.6％.XRD和SEM分析结果表明,二氧化钛为结晶良好的锐钛矿型,粒径大约为8nm.漂浮型纳米TiO2/EP有较广阔的工程应用前景.     

漂珠负载Fe3+改性TiO2复合光催化剂的制备及光催化活性研究

利用溶胶-凝胶法实现了Fe3+掺杂的二氧化钛(TiO2)膜层在漂珠表面的负载,成功制备出Fe-TiO2/漂珠复合光催化剂。以亚甲基蓝为降解对象,研究其在可见光下的光催化效果,并结合SEM,XRD,UV-vis,FTIR等表征手段较为系统的研究了复合光催化剂的表面形态,晶型结构,光响应范围以及各种微观变化等。实验结果表明:Fe-TiO2/漂珠的光催化降解效率优于TiO2/漂珠。煅烧温度为450℃,Fe/Ti摩尔比为0.01%条件下制备的复合光催化剂降解性能最好。     

CdS/TiO2复合纳米粒子的制备及其产氢性能研究

采用化学沉淀法制备了CdS包覆TiO2（CdS/TiO2）复合纳米粒子,利用XRD、TEM、SEM、UV-vis吸收光谱等对其进行了表征分析,并以可见光分解水制氢为探针反应考察了复合纳米粒子的活性。结果表明,CdS/TiO2 复合纳米粒子的颗粒大小约为40nm,TiO2 以锐钛矿型存在,CdS以六方相存在;复合纳米粒子的吸收光谱较TiO2 发生“红移”,大幅拓宽了对可见光区的吸收范围。光解水制氢实验表明,CdS/TiO2 复合纳米粒子具有良好的可见光释氢活性和光学稳定性。     

CdS纳米粒子的室温固相反应制备及其光催化活性研究

以牛血清白蛋白为稳定剂,采用CdSO4.8H2O、硫脲和NaOH之间的室温固相反应制备了高分散立方晶相粒径为4~5 nm的CdS纳米颗粒。用X射线洐射(XRD)、透射电镜(TEM)和原子力显微镜(AFM)对CdS纳米颗粒的相组成,形貌和粒径等进行了表征。以甲基橙降解脱色为探针反应,研究了自然光照条件下,CdS纳米颗粒的光催化活性,即光催化剂用量,试液的pH值,光照及时间等与甲基橙脱色率的关系。在最佳光催化剂用量为0.2 g,最佳pH值为1时,太阳光照射1 min,甲基橙降解率可达99%以上,表明由室温固相反应制备的CdS纳米颗粒,具有优异的光催化活性。     

新型CdS/TiO_2纳米复合材料的制备及其可见光催化性能研究

采用浸渍法和水热法相结合制备了新型的CdS/TiO_2纳米复合材料,并采用X射线衍射(XRD)、透射电子显微镜(TEM)、UV-Vis吸收光谱(UV- VIS)、电子自旋共振谱(ESR)等对样品进行了表征,XRD、TEM表明所制备的新型CdS/TiO_2粒径小、分散均匀,TiO_2以锐钛矿型存在,CdS以高分散的立方相和六方相存在,对比直接法制备的CdS/TiO_2,新型的CdS/TiO_2对活性艳红X-3B具有明显提高的可见光催化活性;大量的束缚单电子氧空位及电子之间强相互作用是新型CdS/TiO_2可见光催化活性提高的主要原因.     

坡缕石/Al掺杂CdS复合材料光催化降解罗丹明B

采用溶剂热法制备了坡缕石/Al掺杂CdS复合材料(PGS/CdS-Al),运用XRD、XPS、SEM、UV-Vis DRS及PL对材料的结构、形貌以及光学性能进行了表征.结果表明,Al元素成功掺杂到CdS中,CdS的晶体结构没有改变,但其禁带宽带变宽.可见光照射下,该复合材料对孔雀石绿、亚甲基蓝、甲基橙、结晶紫、罗丹明B有机染料均有光催化降解活性,且对罗丹明B的光催化降解效果最好.光照40 min,质量浓度为0.67 g/L 15％PGS/CdS-Al(15％为PGS的负载量,以生成的CdS质量计)对30 mL质量浓度为20 mg/L罗丹明B的降解率为98.7％,反应主要活性基团是h+.该降解反应符合一级动力学,反应速率常数为0.067 min–1.     

A facile solid-state heating method for preparation of poly(3,4-ethelenedioxythiophene)/ZnO nanocomposite and photocatalytic activity

Poly(3,4-ethylenedioxythiophene)/zinc oxide (PEDOT/ZnO) nanocomposites were prepared by a simple solid-state heating method, in which the content of ZnO was varied from 10 to 20 wt%. The structure and morphology of the composites were characterized by Fourier transform infrared (FTIR) spectroscopy, ultraviolet-visible (UV-vis) absorption spectroscopy, X-ray diffraction (XRD), and transmission electron microscopy (TEM). The photocatalytic activities of the composites were investigated by the degradation of methylene blue (MB) dye in aqueous medium under UV light and natural sunlight irradiation. The FTIR, UV-vis, and XRD results showed that the composites were successfully synthesized, and there was a strong interaction between PEDOT and nano-ZnO. The TEM results suggested that the composites were a mixture of shale-like PEDOT and less aggregated nano-ZnO. The photocatalytic activity results indicated that the incorporation of ZnO nanoparticles in composites can enhance the photocatalytic efficiency of the composites under both UV light and natural sunlight irradiation, and the highest photocatalytic efficiency under UV light (98.7%) and natural sunlight (96.6%) after 5 h occurred in the PEDOT/15wt%ZnO nanocomposite.     

活性炭纤维负载TiO2薄膜的制备及对亚甲基蓝的光催化降解

采用浸渍-水解法,制备了活性炭纤维(ACF)负载TiO2薄膜。通过XRD、SEM与XPS对膜进行了表征,并研究了该负载型催化剂对亚甲基蓝的光催化降解性能。结果表明,所得薄膜为锐钛矿晶型,在其循环使用过程中,经140 m in光催化反应对亚甲基蓝的去除率始终维持在99.8%~99.9%,说明该产品对亚甲基蓝具有高的光催化活性和重复利用性。在有无紫外光照两种情况下,通过比较所制备催化剂在5次循环使用中对亚甲基蓝的去除性能,以及降解产物中铵离子的浓度变化,证明亚甲基蓝的去除是被TiO2降解而不是被ACF吸附。     

Graphene-enhanced visible-light photocatalysis of large-sized CdS particles for wastewater treatment

The hybrid composites of graphene decorated by large-sized CdS particles (G/M-CdS) were prepared by a one-pot solvothermal route in which the reduction of graphite oxide into graphene was accompanied by the generation of microsized CdS particles. The structure and composition of the obtained nanocomposites were studied by means of X-ray diffraction, scanning electron microscopy, and transmission electron microscopy. The CdS particles with the average sizes of approximately 640 nm were formed on graphene sheets. The as-prepared composite was used as adsorbent to remove dye from wastewater using the organic dye Rhodamine B as the adsorbate. The G/M-CdS composite reveals a high photodegradation rate under visible light irradiation. Our results demonstrate that the G/M-CdS is very promising for removing organic dyes from wastewater.     

Hierarchically plasmonic photocatalysts of Ag/AgCl nanocrystals coupled with single-crystalline WO(3) nanoplates

The hierarchical photocatalysts of Ag/AgCl@plate-WO(3) have been synthesized by anchoring Ag/AgCl nanocrystals on the surfaces of single-crystalline WO(3) nanoplates that were obtained via an intercalation and topochemical approach. The heterogeneous precipitation process of the PVP-Ag(+)-WO(3) suspensions with a Cl(-) solution added drop-wise was developed to synthesize AgCl@WO(3) composites, which were then photoreduced to form Ag/AgCl@WO(3) nanostructures in situ. WO(3) nanocrystals with various shapes (i.e., nanoplates, nanorods, and nanoparticles) were used as the substrates to synthesize Ag/AgCl@WO(3) photocatalysts, and the effects of the WO(3) contents and photoreduction times on their visible-light-driven photocatalytic performance were investigated. The techniques of TEM, SEM, XPS, EDS, XRD, N(2) adsorption-desorption and UV-vis DR spectra were used to characterize the compositions, phases and microstructures of the samples. The RhB aqueous solutions were used as the model system to estimate the photocatalytic performance of the as-obtained Ag/AgCl@WO(3) nanostructures under visible light (λ≥ 420 nm) and sunlight. The results indicated that the hierarchical Ag/AgCl@plate-WO(3) photocatalyst has a higher photodegradation rate than Ag/AgCl, AgCl, AgCl@WO(3) and TiO(2) (P25). The contents and morphologies of the WO(3) substrates in the Ag/AgCl@plate-WO(3) photocatalysts have important effects on their photocatalytic performance. The related mechanisms for the enhancement in visible-light-driven photodegradation of RhB molecules were analyzed.     

Synthesis, characterization and photoelectrochemical properties of poly(3,4-dioctyloxythiophene)-CdS hybrid electrodes

CdS-poly(3,4-dioctyloxythiophene) (CdS-PDOT) hybrid electrode has been prepared by electrosynthesis of PDOT on Au substrate followed by electrodeposition of Cd and its chemical transformation into CdS. The polymer and semiconductor obtained by this method form hemispherical structures dispersed on the substrate. The synthesized composites were characterized by UV-vis absorption spectra and energy dispersive X-ray spectra (EDS). The AFM images of the electrodes covered with different amounts of each component were correlated with photoactivity of the hybrid electrodes. Photoresponses of Au/PDOT-CdS electrodes under illumination in aqueous solution of Na₂S were also compared with those of CdS without polymer. Enhancement of the photocurrent achieved for some polymer-to-semiconductor ratio is discussed in terms of the hybrid electrode morphology and hole-mediating properties of PDOT. The power conversion efficiency of the device based on CdS-PDOT hybrid electrode was determined from photocurrent-potential behavior of two electrode system, Au/CdS-PDOT/0.1 M Na₂S/Pt with a variable resistance in series in the external circuit.