Photocatalytic Oxidation of Isopropanol in Aqueous Solution Using Perovskite‐Structured La2Ti2O7

This study is focused on the application of a highly‐doped layered perovskite, La₂Ti₂O₇, as the photocatalyst for the photocatalytic decomposition of isopropanol (IPA). The La₂Ti₂O₇ powder prepared by solid state reaction was characterized by X‐ray diffraction (XRD), scanning electron microscopy (SEM), UV‐Vis diffuse reflectance spectrophotometry (UV‐DRS), X‐ray photoelectron spectroscopy (XPS), and zeta potential. The temporal behavior of the photocatalytic decomposition of IPA in aqueous solution by the UV/La₂Ti₂O₇, with a photoreactor operated in a recirculation mode, was studied under various conditions including solution pH, light intensity, and La₂Ti₂O₇ loading. The decomposition of IPA in aqueous solution by La₂Ti₂O₇ photocatalytic processes was found to be technically feasible. A kinetic equation was developed for modeling the photocatalytic decomposition of IPA by the UV/La₂Ti₂O₇ photocatalytic processes.     

A Visible Light Photocatalyst of Carbonate‐Like Species Doped TiO2

Carbon‐doped TiO₂ nanomaterials have been successfully synthesized via an effective two‐step procedure involving hydrothermal method and followed by a low‐temperature calcination treatment process, through which a controllable amount of carbonate‐like species could be incorporated into TiO₂. First‐principles calculations suggest the TiO₂ doped with carbon in form of carbonate‐like species can effectively extend the adsorption of the material from ultraviolet region to visible light. And it is experimentally found that carbon‐doped TiO₂ nanomaterials exhibit much higher photocatalytic activity than reference P25 and TiO_2?xN_x catalysts toward the liquid‐phase degradation of organic pollutants under visible light (420 nm < λ < 800 nm) irradiation. The presence of synergic effect between carbonate‐like doping and anatase TiO₂ is believed to play an essential role in affecting the photocatalytic reactivity, and the response to the visible light is ascribed to the narrowed band gap energy controlled by carbon doping. Moreover, the roles of active species in the photocatalytic process are compared using different types of active species scavengers. Meanwhile, the degradation mechanism of the photocatalysis is proposed. It is hoped that our work could provide valuable information on the design of carbonate‐like doped semiconductor with more excellent properties and set the foundation for the further industrial application.     

Photocatalytic Degradation of Isopropanol Over PbSnO3 Nanostructures Under Visible Light Irradiation

Nanostructured PbSnO₃ photocatalysts with particulate and tubular morphologies have been synthesized from a simple hydrothermal process. As-prepared samples were characterized by X-ray diffraction, Brunauer–Emmet–Teller surface area, transmission electron microscopy, and diffraction spectroscopy. The photoactivities of the PbSnO₃ nanostructures for isopropanol (IPA) degradation under visible light irradiation were investigated systematically, and the results revealed that these nanostructures show much higher photocatalytic properties than bulk PbSnO₃ material. The possible growth mechanism of tubular PbSnO₃ catalyst was also investigated briefly.     

Mn2+掺杂ZnIn2S4多孔光催化剂催化产氢性能研究

以溴代十六烷基吡啶(CPBr)为模板剂,采用水热法制备出系列Mn2+掺杂的ZnIn2S4多孔光催化剂.通过XHD、FESEM、UV-Vis、XPS等分析手段对催化剂进行了表征,考察了掺杂Mn2+浓度对多孔ZnIn2S4光催剂的形貌结构和可见光催化产氢性能的影响.实验结果表明,Mn2+掺杂影响催化剂的晶体结构及其微观形貌...     

掺杂改性TiO2可见光光催化剂研究的最新进展

纳米TiO2在紫外光照射下具有良好的光催化活性,在环境污染物治理方面具有重要的应用前景。为提高TiO2对可见光的吸收,常常需要对TiO2进行掺杂改性以缩小其禁带宽度。本文综述了近些年来国内外在金属掺杂、非金属掺杂、金属-金属共掺杂、金属-非金属共掺杂、非金属-非金属共掺杂以及杂多酸盐掺杂改性TiO2光催化剂方面的最新进展,并对TiO2可见光光催化剂的研究进行了展望。     

可见光下上转换发光材料掺杂纳米TiO2的光催化活性研究

印染工业的发展加剧了环境污染,传统的处理染料废水的方法存在许多难以克服的缺点.从保护环境和节省能源的角度出发,人们对TiO2应用在染料污水降解领域的研究给予了较大的关注.本文制备出上转换发光材料掺杂的纳米TiO2光催化剂.用XRD和TEM对这种催化剂进行了表征,通过在可见光下降解亚甲基兰溶液对样品的光催化活性进行了评价,研究了掺杂浓度,样品投放量以及光照时间对催化剂的光催化活性的影响.结果表明掺杂样品在可见光下能有效地分解有机物,而未掺杂样品则产生了大量有毒中间产物,因此上转换发光材料掺杂的TiO2光催化剂在可见光下具有较好的光催化活性.     

Porogen Template Assisted TiO2 Rutile Coupled Nanomaterials for Improved Visible and Solar Light Photocatalytic Applications

The controlled synthesis, using Brij56, PEG, PVA and CTAB organic porogens, of TiO₂ rutile-coupled nanomaterials leads to efficient visible and solar light photocatalytic materials at room temperature. Examples are provided for the total oxidation of CO, the production of hydrogen from water splitting and the gas phase diethylsulfide degradation.     

Preparation and Characterization of Bi3+‐TiO2 and its Photocatalytic Activity

Bi³⁺‐TiO₂ photocatalysts were prepared by doping bismuth ion into the TiO₂ structure in a sol‐gel process. The catalyst samples were then characterized by UV‐vis diffuse reflectance spectra (DRS), X‐ray photoelectron spectroscopy (XPS), Fourier transform infrared spectroscopy (FT‐IR), X‐ray diffraction (XRD) and transmission electron microscopy (TEM). Rodamine‐B (RhB) was used in this study as a model chemical with the aim of organic pollutants control. The photocatalytic degradation of RhB demonstrated that an optimal loading of bismuth 0.7 at. % achieved the highest photodegradation rate, with the rate constant increasing by a factor of 3.89 over neat TiO₂ (P25) under UV illumination (λ ≥ 320 nm). The degradation of p‐nitrobenzonic acid (pNBA) was also examined to prevent/preclude/exclude/ the photosensitization pathway. GC‐MS results show that pNBA can be effectively degraded and minerized to small molecules, such as quinone, acetic acid and formic acid.     

铈掺杂纳米二氧化钛可见光光催化降解苯酚性能

研究了Ce掺杂纳米二氧化钛作为光催化剂,在可见光条件下光催化降解苯酚的过程,并分别测试了Ce掺杂量、锻烧温度、焙烧时间、pH值以及催化剂用量等因素对苯酚溶液光催化降解过程的影响,同时总结了铈掺杂纳米二氧化钛可见光光催化降解苯酚性能的最佳条件,以希冀给予相关研究人员一些可行性的帮助和指导。     

Solar‐Assisted Photocatalytic Degradation of Benzoic Acid Using Titanium Dioxide as a Photocatalyst

The photocatalytic degradation of benzoic acid using titanium dioxide (Degussa P‐25) as a photocatalyst has been studied. The effects of various anions, which are common in industrial wastewater, and of the initial pH were also studied. The effect of the presence of low concentration of cations was also studied. From the intermediates detected a photocatalytic degradation pathway for benzoic acid has been proposed.     

XPS研究共掺杂TiO2可见光光催化活性

利用X-射线光电子能谱(XPS)分析掺杂元素对二氧化钛中O1s和Ti2p的结合能峰的变化。从实验数据求出△(O-Ti)值,分析变化的原因。数据显示:共掺杂后△(O-Ti)的值的变化范围为71.2～71.5 eV之间,掺杂后△(O-Ti)值大于纯TiO2。可见光光催化氧化4-氯苯酚结果表明:随着△(O-Ti)值的增大,可见光光催化活性逐步提高。     

介孔TiO2的制备及染料敏化光催化制氢性能研究

文章利用CTAB为模板剂,以水热法制备介孔TiO2。并用虎红（Rose bengal）进行染料敏化制备了具有可见光活性的光催化剂,分别运甩UV-Vis、XRD、FT-IR和BET等手段对催化剂进行了表征,通过光解水制氢为反应模型考察了所制备催化剂的光催化活性。结果表明：用该方法合成的介孔TiO2具有较高的比表面和催化活性,活性顺序为：介孔TiO2〉P25〉溶胶凝胶捌备的TiO2（500℃煅烧）。     

稀土上转光剂掺杂纳米TiO2催化可见光降解甲基紫

合成了一种新型含有稀土金属Er的上转光剂,此上转光剂在488nm可见光的激发下,可产生5个波长均小于387nm的上转换紫外发射峰。采用超声波分散的方法制备出了上转光剂掺杂的纳米TiO2,可见光光催化剂。实验结果表明,作为掺杂成分的上转光剂可有效地将可见光转化为紫外光并被纳米TiO2粉末吸收利用, 紫外光谱和离子色谱分析表明,在可见光照射16小时后甲基紫分解产物为Cl-和NO3-等,其降解率达92．2%, 大大高于未掺杂纳米TiO2的降解率71．2％。     

Oxidation of Phenol by Microbubble‐Assisted Microelectrolysis

The degradation of phenol under microelectrolysis was enhanced by O₂‐microbubbles. Phenol solution was circled in a microbubble‐assisted microelectrolysis reactor under acid conditions. The degradation rate of phenol reached 65 % within 2 h with O₂‐microbubbles, compared to 9.5 % and 4 % with air‐ and N₂‐microbubbles due to better dissolution of oxygen with finer microbubbles and at higher dissolution pressure. Higher efficiencies of phenol degradation at lower temperature further confirm the role of dissolved oxygen. In the microbubble‐assisted microelectrolysis system dissolved oxygen, carbon steel pellets, and sulfuric acid are necessary conditions for the oxidation of phenol. The conversion of phenol increases with an increasing amount of carbon steel pellets and/or sulfuric acid. Catechol, hydroquinone, and low‐molecular‐weight carboxylic acids are the major products.     

Visible Photocurrent in Chemically Doped TiO2‐Based Schottky Diodes

The delicate tuning of TiO₂ electronic structure is essential to achieve the maximized photoresponse of light harvesting energy devices such as photocatalysis and photovoltaic cells. In this study, the photocurrent response of TiO₂‐based diodes with and without Fluorine doping method was investigated. The differences in electronic structure between undoped and F‐doped TiO₂ thin films are associated to the Fermi energy level which determines the available empty state energy against the valence band maximum. The incident photoconversion efficiency results indicate that the visible photoabsorption process and charge transport can be enhanced by energy matching between subgap states in TiO₂ and the interference light and provides an effective strategy for light harvesting using TiO₂.     

微波辅助制备TiO_2/CNTs复合材料及可见光光催化性能研究

文章以六氟钛酸铵、硼酸、碳纳米管为反应物,在低温(100℃)和常压体系下,采用微波辅助法制备二氧化钛/碳纳米管复合材料(TiO_2/CNTs)光催化剂。采用X射线粉末衍射(XRD)、场发射扫描电子显微镜(FESEM)及紫外-可见漫反射光谱对TiO_2/CNTs进行表征。采用TiO_2/CNTs为催化剂光催化降解罗丹明B,研究了TiO_2/CNTs的可见光光催化活性。测试结果表明,在可见光照射下制备得到的TiO_2/CNTs具有比Degussa P25光催化剂更优越的光催化降解活性。     

N修饰纳米TiO2可见光催化降解氮氧化物

为了充分利用可见光催化转化氮氧化物,采用碳酸铵作为N源,用浸渍的方法制备了掺N的纳米TiO2。XRD分析结果表明,修饰和煅烧过程没有改变TiO2的晶型;由X光电子能谱(XPS)可得,N在TiO2晶格中形成N—Ti—O键;催化剂的UV-Vis漫反射光谱显示,N修饰TiO2催化剂的吸收光谱发生了一定程度的红移,在可见光区有一定的吸收。N修饰TiO2催化在蓝光照射下对NO2有一定的转化。合适的N修饰量和煅烧温度对修饰过程非常重要,m[(NH4)2CO3]/m(TiO2)为0.20的混合物在600℃下煅烧1.0 h的催化剂在可见光下转化NO2的活性最高。     

Indirect Electrochemical Oxidation of Phenol in the Presence of Chloride for Wastewater Treatment

Electrochemical oxidation of phenol using a Ti/TiO₂‐RuO₂‐IrO₂ anode in the presence of chloride as the supporting electrolyte was investigated. The experiments were performed in an undivided batch reactor. Preliminary investigations showed that only a small fraction of phenol was oxidized by direct electrolysis, while complete degradation of phenol was achieved by indirect electrochemical oxidation using chloride as a supporting electrolyte. The effect of operating parameters such as initial pH, supporting electrolyte concentration, phenol concentration, and charge input was studied using Box‐Behnken second order composite experimental design. The effect of current density on COD removal was studied separately. TOC removal and AOX formation were studied for selected conditions. It was found that the formation of chlorinated organic compounds was pronounced at the beginning of electrolysis, but it was reduced to lower levels by extended electrolysis.     

sp2碳共价有机框架可见光催化水分子氧化

为开发出具有强π-π共轭效应、优异可见光转化性能及高光催化析氧反应（OER）活性的共价有机框架（COFs）材料， 以具有较大共轭结构的N,N’-对乙腈苯-3,4,9,10-萘二酰亚胺和1,3,5-三(对甲酰基苯基)苯为单体，通过溶剂热方法合成了sp2碳连接构筑的六方孔状的NP-COF，并通过结构、形貌、光电性能表征表明了NP-COF是一种吸光性能良好、具有一定的载流子产生和迁移能力优势的半导体型催化剂，能够在可见光诱导下高效地催化水分子氧化反应的进行，在7.4 mg Co(NO3)2?6H2O作为助催化剂的条件下平均产氧速率达344 μmol/(g·h)。     

Photodegradation of o‐Cresol with Ag Deposited on TiO2 under Visible and UV Light Irradiation

This study investigated the effect of dosage of Ag on the characteristics of TiO₂, quantum yield, and temporal decomposition behavior of o‐cresol in an annular reactor under ultraviolet (UV) and visible light irradiation. In order to extend light absorption and minimize the rapid recombination during photoreaction, the Ag deposited on TiO₂ photocatalysts was prepared by a photodeposition process. The results of diffuse reflectance spectra (DRS) indicated that Ag deposited on TiO₂ promoted the optical absorption in the visible region and made it possible for it to be excited by visible light. The degradation rate of o‐cresol with 0.50 wt % Ag/TiO₂ under visible light irradiation was 2.0 times that with pure TiO₂.