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1.
以乌洛托品为孔形成剂,制备出孔结构可调控的粉煤灰基地质聚合物;通过半导体耦合设计,合成出In_2O_3和NiO双负载粉煤灰基地质聚合物催化剂;采用XRF、TGA/DSC、FESEM、XRD、FT-IR、UV-Vis等对催化剂的组成、结构及性能进行表征,考查了该催化剂体系对模拟印染废水的光催化降解活性、降解机理及反应动力学。结果表明:孔形成剂的掺入能够显著地改善地质聚合物的孔结构,调变BET比表面积及介孔体积;双负载5%In_2O_3及1%NiO的粉煤灰基地质聚合物催化剂对碱性品绿染料的最高降解率(95.65%),归因于In_2O_3与NiO形成的p-n结半导体耦合体系以及In_2O_3与PAFAG载体之间产生强相互作用,改善了光生电子-空穴对的分离效率,从而提高了光催化染料降解活性。 相似文献
2.
利用微波辅助溶剂热法合成了In-Si 共改性的TiO 2 光催化剂. 粉末X 射线衍射(XRD)、激光拉曼(Raman)光谱、N 2吸脱附(BET)、X射线光电子能谱(XPS)、光致发光(PL)光谱和紫外-可见漫反射光谱(UV-VisDRS)等实验表明,尽管掺杂和改性后TiO 2结晶度略有降低,但不影响光催化剂锐钛相的形成. Si 掺杂入TiO 2晶格使颗粒变小,比表面积变大. In 不能进入TiO 2晶格,在TiO 2表面形成了In 2O 3. 罗丹明B(RhB)降解实验显示,In-Si 共改性TiO 2表现出很高的紫外和可见光催化活性,Si:In:Ti 的摩尔比为0.03:0.02:1 的样品(IST-2)光催化活性最高,紫外光下3 min 即可将RhB降解完全,可见光下120 min RhB降解率为97%,这是由材料的高表面积,In 2O 3-TiO 2复合半导体之间高效电荷转移及染料敏化等共同作用所致. 对于苯酚,光催化降解则相对缓慢,700 min内尚不能降解完全. 相似文献
3.
以TiCl 3和InCl 3为Ti源和In源,在不使用还原剂的条件下,首先通过液相沉淀反应制备前驱体沉淀,然后采用后续水热处理制备Ti 3+自掺杂的TiO 2(A)/TiO 2(R)/In 2O 3纳米异质结,考察了水热处理温度对材料结构和性能的影响。利用X射线衍射、透射电子显微镜、X射线光电子能谱和紫外-可见漫反射光谱对样品进行表征。分别以罗丹明B和苯酚溶液为模拟废水评价了样品的可见光催化降解性能。结果表明,与纯的TiO 2、In 2O 3以及Ti 3+自掺杂的TiO 2相比,Ti 3+自掺杂的TiO 2(A)/TiO 2(R)/In 2O 3纳米异质结在可见光区有明显的吸收,并具有良好的可见光催化降解性能,200℃下水热处理24 h所得样品光催化降解罗丹明B的反应速率常数(0.0444 min -1)分别是纯TiO 2和In 2O 3的17.76倍和8.71倍。瞬态光电流时间响应结果表明样品的光催化性能主要来源于TiO 2(A)/TiO 2(R)/In 2O 3纳米异质结导致的提高的光生电子和空穴分离效率。 相似文献
4.
为提高光热催化CO 2加氢In 2O 3催化剂的催化活性,采用均相水热法制备Mg (OH) 2-In (OH) 3前驱体,通过高温煅烧和H 2-还原处理得到了富含氧空位的Mg掺杂In 2O 3-x(Mg-In 2O 3-x)催化剂。在300℃、常压、可见光照射条件下,CO 2加氢转化为CO的CO 2转化率可达31.20%,CO产生速率为14.22 mmol·g cat-1·h -1,CO选择性为100%。相比于单一In 2O 3-x催化剂,Mg-In 2O 3-x催化剂光热催化CO 2转化率及CO产生速率明显提高,这归因于Mg成功掺杂到In 2O 3晶格中,促进In 2O 3表面氧空位的形成,进而对可见光响应效率大幅提高,并有效减缓光生电子-空穴的复合。 相似文献
5.
为提高光热催化CO 2加氢催化剂In 2O 3的催化活性,采用均相水热法制备Mg(OH) 2-In(OH) 3前驱体,通过高温煅烧和H 2-还原处理得到了富含氧空位的Mg掺杂In 2O 3-x(Mg-In 2O 3-x)催化剂。在300℃、常压、可见光照射条件下,CO 2加氢转化为CO的CO 2转化率可达31.20%,CO产生速率为14.22 mmol·gcat -1·h -1,CO选择性为100%。相比于单一In 2O 3-x催化剂,Mg-In 2O 3-x催化剂光热催化CO 2转化率及CO产生速率明显提高,这归因于Mg成功掺杂到In 2O 3形晶格中,促进In 2O 3表面氧空位的形成,进而对可见光响应效率大幅提高,并有效减缓光生电子-空穴的复合。 相似文献
6.
以Pt-TiO 2为光催化剂,研究了气相甲醛分别在35 h连续UV 254 nm光催化、O 3强化UV 254 nm(O 3+UV 254 nm)光催化和真空紫外(UV 254+185 nm)光催化中的降解效率,考察了副产物O 3的去除率,采用X射线光电子能谱(XPS)法分析Pt-TiO 2在不同光催化前后Pt的电子态和累积有机产物,研究纳米Pt对甲醛降解和O 3去除的强化机理. 连续光催化降解实验表明,以纳米Pt改性TiO 2可以同时增强甲醛和O 3的去除率,特别是O 3的去除率可提高3.1-3.4倍. 对催化剂C 1s和O 1s峰分别经分峰拟合处理后,发现Pt-TiO 2上累积的含羰基和羟基的有机物含量按以下顺序减少:UV 254 nm光催化 > O 3强化UV 254 nm光催化 > 真空紫外光催化,而在连续35 h光催化降解过程中,催化剂的失活现象却按相反的方向变得越来越不明显. 负载的金属Pt在O 3+UV 254 nm和UV 254+185nm光催化过程中被氧化成PtO ads和Pt 4+物种,而在UV 254 nm光催化过程中金属Pt未被氧化,所以推测是气相中的O 3和羟基自由基参与金属Pt的氧化过程. Pt-TiO 2表面高价态的Pt氧化物种可作为光生电子捕获中心,强化光生载流子的分离过程,增强Pt-TiO 2的光催化活性. Pt氧化物种可作为O 3分解的活化中心,使Pt-TiO 2对O 3的分解效率远高于纯TiO 2. 以XPS对比研究在三种不同光催化环境中Pt-TiO 2表面性质,可以解释在UV 254+185 nm光催化过程中纳米Pt对甲醛和O 3同时去除的强化机理,并说明了催化剂不失活的内在原因. 相似文献
7.
以掺氟SnO 2 (FTO)导电玻璃为基底, 采用水热法制备了ZnO纳米棒阵列. 通过In(NO 3) 3水溶液水洗的方法, 合成了In 2O 3敏化ZnO纳米棒阵列光催化剂. 采用场发射扫描电子显微镜(FESEM), X射线能谱(EDX), X射线衍射(XRD)及紫外-可见漫反射光谱(UV-Vis DRS)对样品的形貌、结构、组成、晶相等进行一系列的表征. 以罗丹明B (RhB)为目标降解物, 探究了In 2O 3敏化ZnO 纳米棒阵列光电催化活性. 采用场诱导表面光伏技术(FISPV)研究了不同含量的In 2O 3敏化ZnO纳米棒阵列在光照射下的光生电荷行为. 结合电化学工作站检测不同样品的光电流, 随着In 2O 3敏化量的改变, 光电流和开路电压也随之改变. 并探讨了In 2O 3敏化ZnO纳米棒阵列光生电荷行为与光电催化活性之间的关系. 结果表明, 适量In 2O 3敏化的ZnO光催化剂在可见光下2 h内对罗丹明B的降解效率达到95%, 是单纯ZnO纳米棒阵列的2.4倍. 相似文献
8.
发展高效的可见光催化剂是太阳能化学利用的一个挑战. 本文采用简单的混合方法, 制备了WO 3和Fe 2O 3的混合物, 研究了该复合氧化物在H 2O 2存在下光催化降解有机染料X3B的活性. 实验表明, 催化剂的光催化活性与其煅烧温度和Fe 2O 3含量有关. 最佳煅烧温度和Fe 2O 3含量分别等于400 °C 和1.0% (w). 根据自由基捕获电子顺磁共振(EPR)波谱分析, 复合氧化物产生羟基自由基的量远高于Fe 2O 3和WO 3. 我们推测, 这种协同效应来源于WO 3和Fe 2O 3之间的电荷转移, 从而加快半导体光生载流子的分离和X3B的光催化降解. 相似文献
9.
采用表面改性法和等体积浸渍法制备了NiO-V 2O 5/SiO 2和Cu/NiO-V 2O 5/SiO 2光催化剂. 用TPR, XRD, UV-Vis DRS, IR和TPD-MS技术对催化剂的结构、吸光性能和化学吸附性能进行了表征, 研究了催化剂上CO 2和甲醇光促表面催化反应的反应性能. 结果表明, 半导体NiO和V 2O 5复合后部分形成了Ni 2+—O—V 5+键联, 而且NiO和V 2O 5在催化剂表面有相互修饰作用, NiO的加入有助于提高V 2O 5在载体SiO 2表面的分散程度, 抑制V 2O 5的聚集, 而且金属Cu和NiO的引入扩展了催化剂的光响应范围. 在催化剂表面存在多种活性吸附位, 催化剂对CO 2和甲醇的有效吸附使得其在较低温度下就能促进碳酸二甲酯的紫外光化学合成. 用Cu/NiO-V 2O 5/SiO 2催化剂, 在常压、空速300 h -1、140 ℃和125 W紫外灯辐照的情况下, CH 3OH的转化率为14.2%, 碳酸二甲酯的选择性可达89.9 %. 相似文献
10.
采用表面改性法和等体积浸渍法制备了NiO-V 2O 5/SiO 2和Cu/NiO-V 2O 5/SiO 2光催化剂. 用TPR, XRD, UV-Vis DRS, IR和TPD-MS技术对催化剂的结构、吸光性能和化学吸附性能进行了表征, 研究了催化剂上CO 2和甲醇光促表面催化反应的反应性能. 结果表明, 半导体NiO和V 2O 5复合后部分形成了Ni 2+—O—V 5+键联, 而且NiO和V 2O 5在催化剂表面有相互修饰作用, NiO的加入有助于提高V 2O 5在载体SiO 2表面的分散程度, 抑制V 2O 5的聚集, 而且金属Cu和NiO的引入扩展了催化剂的光响应范围. 在催化剂表面存在多种活性吸附位, 催化剂对CO 2和甲醇的有效吸附使得其在较低温度下就能促进碳酸二甲酯的紫外光化学合成. 用Cu/NiO-V 2O 5/SiO 2催化剂, 在常压、空速300 h -1、140 ℃和125 W紫外灯辐照的情况下, CH 3OH的转化率为14.2%, 碳酸二甲酯的选择性可达89.9 %. 相似文献
11.
NiS (nickel sulfide)–In 2O 3 (indium oxide) nanostructures and NiS–In 2O 3 decorated on graphene oxide (GO) were demonstrated by ultrasonic/hydrothermal method. The structural study demonstrates the preparation of bixbyite and hexagonal phase of In 2O 3 and NiS for all of the synthesized catalysts. The band gap of the synthesized catalyst was determined to be in the range of 2.30–3.00 eV. A morphological evaluation by field emission scanning electron microscopy of NiS–In 2O 3 decorated on graphene oxide shows support for the NiS–In 2O 3 on the graphene oxide layer. Different test parameters were performed to study the phase and morphology. The particle sizes of the In 2O 3, NiS–In 2O 3 and NiS–In 2O 3/GO nanocomposites were 56.0, 62.0 and 66.0 nm, respectively. The photocatalytic performance of NiS–In 2O 3/GO nanocomposites was examined for the degradation of methylene blue dye under a UV lamp. The prepared sample shows 98.25% photocatalytic degradation within 40 min and at pH 9. With the presence the NiS and GO, the photo-degradation capacities of In 2O 3 and NiS–In 2O 3 are improved owing to the low band gap being calculated in UV–vis DRS analysis. The high ratio of NiS causes the highest photocatalytic properties of NiS–In 2O 3 nanocomposites owing to the enhancement of charge separation efficiency and generation of hydroxyl radicals. This study presents a facile and low-cost method to prepare highly active NiS–In 2O 3/GO nanocomposites. The antibacterial data indicate the significant properties of NiS–In 2O 3/GO nanocomposites for this study. 相似文献
12.
In 2O 3/ZnO heterostructured nanotubes with cubic In 2O 3 and hexagonal ZnO were successfully synthesized via the combination of electrospinning and calcination process. The as-prepared materials are investigated by using thermogravimetric and differential scanning calorimetry, fourier transform infrared spectroscope, X-ray diffraction, scanning electron microscope and high-resolution transmission electron microscope techniques. The formation mechanism of In 2O 3/ZnO heterostructured nanotubes based on the kinetics of phase separation which results from the decomposition of polyvinyl pyrrolidone during the calcination process is also discussed in detail. The photocatalytic degradation tests reveal that In 2O 3/ZnO heterostructured nanotubes exhibit the highly improved photocatalytic properties compared with the single-component ZnO and In 2O 3 materials. 相似文献
13.
以十二烷基硫酸钠为模板剂, 采用尿素为沉淀剂, 用均匀沉淀法, 适当控制尿素的水解速度, 制备具有介孔结构的氢氧化镍胶体, 在不同温度下焙烧处理得到孔分布集中的氧化镍介孔分子筛. 结果表明, 在523 K下焙烧得到的氧化镍BET比表面达到477.7 m 2•g -1. 结构表征还显示, 介孔氧化镍的孔壁为多晶结构, 其孔结构形成机理应为准反胶束模板机理. 循环伏安法表明用NiO介孔分子筛制备的电极有很好的电容性能. 与浸渍法和阴极沉淀法制得的NiO相比, 这种介孔结构的NiO能够大量用来制作电化学电容器电极, 并且保持较高的比电容量和良好的电容性能. 相似文献
14.
Cd-doped In 2O 3 was synthesized by a facile solvothermal, template-free preparation method. The phase structure and properties were characterized by various methods. The surface of Cd-doped In 2O 3 became coarse compared with that of pure In 2O 3, according to the scanning electron microscopeimages, which enhanced the ability to absorb the gas. The electron paramagnetic resonance showed that the Cd-doped In 2O 3 can generate more defects and oxygen vacancies. By measuring the gas sensitivity, the response of Cd-doped In 2O 3 was 1.6 times than that of pure In 2O 3. Thus, Cd-doped In 2O 3 can promote gas-sensing performance compared with pure In 2O 3. 相似文献
15.
A nano‐crystalline In 2O 3 was synthesized using calcinations methods and was used as a photocatalyst to degrade sulfan blue (SB) dye. In addition, this study addresses the conditions of the degradation and the factors that influenced the catalysis. In 2O 3 was prepared by calcining In(OH) 3 at heat ranges of 100–700 °C for 24 h. The In 2O 3 was characterized using field emission scanning electron microscopy (FE‐SEM), an X‐ray diffractometer (XRD), thermogravimetric analysis (TGA), and high‐resolution X‐ray photoelectron spectroscopy (HR‐XPS). The activities of these samples were tested for the photocatalytic degradation of SB dye. The results indicated that the In(OH) 3 that was calcined at 300 °C for 24 h had the best performance. 相似文献
16.
Comparative studies of electophysical gas-sensitive properties of semiconductor metal oxides (NiO, WO 3, and In 2O 3) in detecting trace concentrations of chlorine in air at 250–300°C were performed. WO 3 and In 2O 3 film sensors were found to have the best sensitivity, selectivity, and stability. However, WO 3 films are characterized by a longer relaxation time (3 min) compared to In 2O 3 films, for which it is no longer than 30 s. The kinetic and steady-state relative conductivity values of In 2O 3 films as functions of the chlorine concentration in air fall on the same curve in the range 0.01–0.7 ppm. This suggests that the concentration of chlorine in air can be determined from the initial rates of the variation of the relative conductivity of films, which significantly decreases the time of analysis (from 40 to 5 s at a sensor working temperature of 300°C). Changes in air humidity in the range from 40 to 80% have no effect on the initial rates of the variation of the relative conductivity of In 2O 3 films under kinetic conditions. The mechanism of the variation of In 2O 3 film conductivity in detecting chlorine in air was discussed. 相似文献
17.
Nickel oxide (NiO) was synthesized via a one-step facile method. X-ray diffraction analysis confirmed the face-centered cubic structure of NiO. The bonding nature and surface purity were confirmed via Fourier-transform infrared spectroscopy. NiO revealed partial spherical morphology with less particle aggregation. The optical bandgap of NiO was found to be 3.75 eV. Cyclic voltammetry revealed well-defined oxidation and reduction peaks for NiO. The charge–discharge curve exhibited specific capacitance of 184.6 F/g at current density of 0.3 A/g. NiO electrode exhibited longer cyclic stability of 93 % up to 1500 cycles. In addition, NiO + H2O2 revealed efficient photocatalytic degradation of methylene blue (organic pollutant) under visible-light irradiation with degradation efficiency of ~88 %. These results confirm that nanosized NiO is more suitable for dual application. 相似文献
18.
Single-crystalline metastable In 2O 3 nanocrystals with size in the range of 5–30 nm were, for the first time, synthesized by a precursor-dehydration route at 490°C under ambient pressure. The precursor was prepared by a hydrolysis solvothermal reaction using InCl 3·4H 2O as starting materials and ethylenediamine as solvent in the range of 180–230°C. It was found that the precursor had significant effect on the phase composition and phase structure of In 2O 3. Optical properties of the metastable In 2O 3 nanocrystals were investigated. 相似文献
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