Photocatalytic Activity of Pt2 +-doped Bi2O2 Prepared by Sol-gel Method

用溶胶-凝胶法制备了Pt2+掺杂的Bi2O3光催化剂(Pt/Bi原子比分别为1/100、2/100、3/100和4/100),以甲基橙为模拟有机污染对催化剂的光催化性能进行了考察.光催化剂用BET、XRD、XPS和紫外-可见漫反射进行了表征,结果表明Pt/Bi原子比为3/100时催化剂的比表面最高;经500℃焙烧后光催化剂晶型为α- Bi2O3;掺杂Pt2+后Bi2O3在可见光区的吸收增强;掺杂Pt2后Bi4f7/2和O1s结合能均向低能端偏移,催化性能测试结果表明Pt/Bi原子比为3/100时的催化剂活性最高.增加的比表面、对可见光响应增强和结合能向低能端偏移均有利于提高Bi2O3光催化活性.     

金属铈掺杂Bi2O3可见光催化剂的制备

本文以硝酸铋、硝酸铈铵为原料,氨水为沉淀剂,通过共沉淀工艺制备Ce4+掺杂Bi2O3光催化剂。采用XRD、SEM和TEM等手段分析了不同Ce4+/Bi3+比光催化剂的相组成和微观形貌。结果表明所制备的Bi2O3和Ce4+掺杂Bi2O3的相组成均为α-Bi2O3相,颗粒尺寸控制在50nm左右。利用甲基橙作为降解底物,考察了纳米Bi2O3和Ce4+掺杂Bi2O3光催化剂的可见光催化性能以及体系pH值对其光降解性的影响。结果表明,随着Ce4+掺入量的增加,Bi2O3的光催化性能随之增强,当Ce4+/Bi3+比为20:80时,降解率为98%,且在弱酸性环境中,其光降解性能最好。     

光还原法制备Pd/ZnO及其光催化脱色性能研究

用光还原法制备了Pd/ZnO光催化剂(Pd/Zn原子比分别为1/100、2/100和3/100),以甲基橙为模拟有机污染物,对催化剂的光催化脱色性能进行了考察。光催化剂用 XRD、紫外-可见漫反射和表面光电压谱仪进行了表征,结果表明：当 Pd 沉积量为2/100(Pd/Zn)时电子-空恙分离效应最高,且光催化脱色活性最高;沉积Pd后ZnO在可见光区的吸收增强;高的电子-空恙分离效应有利于提高ZnO光催化活性。     

二维ZnO/ Bi3.9Zn0.4V1.7O10.5纳米异质结构的制备及其可见光催化活性

表面建造是提高半导体光催化活性的一种有效方法。本文利用Zn5(CO3)2(OH)6纳米片为基底沉积了BiVO4再通过煅烧成功制备了二维ZnO/Bi3.9Zn0.4V1.7O10.5复合纳米片。通过X射线衍射,透射电镜和元素映像技术表征了所制样品。结果显示随着锌与铋的原子比的上升,ZnO多孔片状的表面逐渐变成Bi3.9Zn0.4V1.7O10.5物质。但其比例高于1:0.02时,在片状Bi3.9Zn0.4V1.7O10.5的区域表面又生长出BiVO4纳米颗粒。漫反射光谱测试显示出ZnO/Bi3.9Zn0.4V1.7O10.5复合物随着锌与铋的原子比的上升其在400~600 nm可见光区的吸收逐渐增强。所制样品在可见光（波长大于420 nm）进行了光催化降解罗丹明B的测试,结果表明在所制样品中,锌与铋的原子比为1:0.0133的ZnO/Bi3.9Zn0.4V1.7O10.5纳米片虽然其可见光的吸收并没有明显增强但却表现出最佳的光催化活性。荧光与电化学测试得出了低含量BZVO的ZnO纳米片可见光催化活性的提高主要是因为表面ZnO/Bi3.9Zn0.4V1.7O10.5异质结构提高了光生载流子的分离与传送。这种二维材料的表面建造有利于光催化的进行。因此,此法可应用于其它二维纳米材料的建造以提高光催化活性。     

g-C_3N_4/BiPO_4光催化剂合成及光催化性能研究

以Bi(NO_3)_3·5H_2O和Na_3PO_4·12H_2O为原料通过水热法合成了Bi PO_4,用g-C_3N_4分子对其表面修饰,利用超声杂化提高磷酸铋的光催化效率和稳定性。采用X射线衍射仪、红外光谱仪、扫描电镜、透射电镜和比表面积及孔隙度分析仪等对其进行了表征,并在光催化反应装置中模拟可见光条件,对合成的g-C_3N_4/Bi PO_4光催化剂以亚甲基蓝为目标降解物时的催化活性进行了系统的研究。结果表明:在掺杂g-C_3N_4之后,可见光条件下Bi PO_4的光催化活性得到较大程度提升。当g-C_3N_4掺杂量为Bi PO_4的7%时,该复合光催化剂在可见光下的光催化活性最高。     

Cu2O/TiO2/Pt复合薄膜的制备及其性能

为了降解环境污染物,通过磁控溅射的方法在玻璃基底上溅射沉积Cu2O/TiO2/Pt复合薄膜。采用X射线衍射仪(XRD)、扫描电子显微镜(SEM)、紫外可见分光光谱仪(UV-vis)和光致发光光谱仪(PL)对复合薄膜的表面形貌和光学性能进行分析。通过可见光下对甲基橙溶液的光催化降解试验研究了薄膜的光催化活性。结果表明:Cu2O/TiO2/Pt复合薄膜共有3层,从下到上依次为Pt层、锐钛矿型TiO2层和Cu2O层。薄膜表面平整致密,由形状规则的球形颗粒组成。Cu2O/TiO2/Pt复合薄膜的光催化活性高于Cu2O/TiO2复合薄膜的和纯TiO2薄膜的光催化活性。光催化活性的提高是由于Pt层的存在进一步抑制了光生电子与空穴的复合,延长了光生载流子的寿命,提高了量子产率,进而有效地改善了薄膜的光催化活性。     

B/Fe2O3共掺杂纳米TiO2可见光下的催化性能

采用溶胶凝胶法制备B/Fe2O3共掺杂TiO2复合光催化材料,并用X射线衍射仪(XRD)、扫描电镜(TEM)和紫外可见漫反射光谱(DRS)对粉体进行表征。结果表明:催化剂以锐钛矿存在的纳米颗粒,直观地显示了物质的形貌,掺杂B能极大提高催化剂的可见光响应。以二氯苯酚(DCP)为降解物质,在紫外和可见光下分别研究了复合催化剂的光催化活性。掺杂B能使吸收光谱红移至可见光区,而进一步掺杂Fe2O3大大提高了催化剂的活性。     

层状Bi2O2CO3可见光催化活性增强机理研究

本文基于第一性原理方法,研究Bi2O22+和CO32-交替层中氧缺陷生成对晶体结构、能带结构以及光学性质的影响,揭示氧缺陷提高Bi2O2CO3可见光催化活性作用机制。计算结果发现,氧缺陷的存在对Bi2O2CO3的晶胞参数和Bi-O键影响较小,但作为电子施主中心可以向周围原子提供电子,造成Bi2O2CO3电荷分布发生变化,有效减小能带间隙,促进Bi2O2CO3对可见光的吸收,且这种现象随着氧缺陷浓度的升高更加明显。值得注意的是,Bi2O22+层和CO32-层氧缺陷的作用不同。CO32-层中氧缺陷的形成导致费米能级附近出现缺陷能级,改变了电子的跃迁方式。相较于CO32-层,氧缺陷更容易存在于Bi2O22+层中,能够更佳有效地减小Bi2O2CO3的能带间隙,进一步促进Bi2O2CO3对可见光的吸收。随着Bi2O22+和CO32-层氧缺陷浓度增加,Bi2O22+层氧缺陷的作用愈明显,当浓度达到6.25%时,Bi2O2CO3在可见光区的响应显著增强,有利于提高Bi2O2CO3可见光催化活性。本文计算结果解释了实验上氧缺陷增强Bi2O2CO3光催化活性现象,并为今后合成其它含氧缺陷Bi基金属氧化物提供理论指导。     

Y2Cu2O5光催化剂的制备及模拟太阳光催化产氢

分别用固相法和液相法制备Y2Cu2O5光催化剂,利用热重差热分析(TG-DTA)、X射线衍射(XRD)、扫描电子显微镜(SEM)、紫外可见光漫反射光谱(UV-Vis DRS)等技术对光催化剂进行表征。在模拟太阳光照射条件下,以草酸(H2C2O4)为牺牲剂对所制得的光催化剂制氢性能进行评价,考察制备方法和牺牲剂类型等因素对其产氢性能的影响以及光催化剂的稳定性能。结果表明:溶胶凝胶法所得样品中含有Y2O3杂质,为Y2Cu2O5与Y2O3的混合物;固相法所得样品为纯净的Y2Cu2O5,具备较高的光催化产氢活性。用固相法制备的光催化剂Y2Cu2O5,当其用量为0.8 g/L、草酸为牺牲剂且初始浓度为0.05 mol/L时,表现出最佳光催化产氢活性,其产氢量为3.78mmol/(h.g)。但Y2Cu2O5在草酸溶液中不稳定,会与草酸反应生成Y2(C2O4)3.2H2O,导致产氢活性降低。     

Nb5+掺杂r-TiO2的光催化分解水析氧活性

用钛酸丁酯低温水解方法合成不同掺杂Nb5 浓度的金红石型TiO2(r-TiO2)光催化剂,采用XRD、PL、DRS和BET等技术进行了催化剂表征.在光源为高压汞灯和氙灯、Fe3 为电子受体、悬浮液的pH值为2.0的条件下,考察Nb5 的掺杂量对r-TiO2粒子的光催化分解水析氧活性的影响,并探讨了掺杂催化剂的DRS,PL光谱与光催化活性的关系.结果表明Nb5 的掺杂量在0.5%～3.0%范围时,Nb5 掺杂没有引起r-TiO2的晶型改变,表面形成氧空位,在导带底附近形成施主能级,有利于光生电子和空穴的分离,掺杂催化剂光催化活性增强;掺杂催化剂光致发光强度与其光催化析氧活性的变化趋势一致,Nb5 掺杂量在1.0%(摩尔分数)时,PL光谱强度最大,光催化析氧活性最高,紫外光源和可见光源析氧速率分别达480 μmol/(L-h)和78 μmol/(L-h);Fe3 的初始浓度为8.0 mmol/L时,催化剂析氧活性最高.     

离子液体辅助制备AgCl/Ag2O复合光催化剂

在离子液体[CPMIm]Cl辅助下,采用沉淀法原位制备了AgCl/Ag2O复合光催化剂。采用X射线衍射仪(XRD)、能量散射光电子能谱(EDS)、扫描电镜(SEM)、比表面仪(BET)和紫外-可见漫反射光谱(UV-Vis DRS)等对AgCl/Ag2O复合光催化剂结构、组成、形貌、比表面积和光吸收性能进行了表征;运用表面光电压谱(SPS)对异质结光催化剂的光生电荷分离特性进行了研究。考察了AgCl/Ag2O复合光催化剂对模拟污染物甲基橙的光催化降解性能。结果表明,AgCl的存在抑制了Ag2O颗粒的生长,增加了复合光催化剂的比表面积和孔容积。AgCl与Ag2O的原位复合有效提高了复合光催化剂光生e^-/h⁺对分离速率,增强了复合光催化剂对甲基橙的光催化降解。捕获测试表明?O2^-是光催化降解甲基橙的主要活性自由基。     

WO3-TiO2复合空心球的制备及其光催化性能

以钛酸四正丁酯和偏钨酸铵为原料,采用水热-模板法制备复合WO3-TiO2光催化剂。利用X射线衍射(XRD)、扫描电子显微镜(SEM)、比表面积(BET)和紫外-可见漫反射(UV-Vis DRS)等手段对催化剂的结构和光学性能进行表征。结果表明:WO3-TiO2复合半导体中的TiO2为锐钛矿晶型,焙烧后的WO3-TiO2呈中空球形结构,粒径在320 nm左右,且粒径分布均匀,其比表面积和平均孔径分别为40.95 m2/g和16.91 nm,WO3-TiO2复合半导体的紫外-可见吸收边带较TiO2的红移约50 nm,并在400~500 nm处有吸收。光降解甲基橙(MO)实验显示:经过80 min光照后,WO3-TiO2复合半导体在紫外和可见光下对甲基橙的降解率分别为99.2%和81%,而TiO2的仅为64%和25%,且在紫外和可见光下WO3-TiO2复合半导体的表观速率常数分别是TiO2的3.2和4.9倍左右。     

Effect of Nd2O3 addition on the surface phase of TiO2 and photocatalytic activity studied by UV Raman spectroscopy

TiO₂ modified with Nd₂O₃ (Nd-TiO₂) nanoparticles were prepared by a co-precipitation method and utilized as the photocatalysts for the degradation of Rhodamine B (RhB). The influence of Nd₂O₃ on the bulk and surface phase, surface area, particle size, and optical response of TiO₂ was investigated by X-ray diffraction (XRD), UV Raman spectroscopy, transmission electron microscopy (TEM), BET, and UV-visible diffuse reflectance spectra. It is found that the crystalline phase and phase composition in the bulk and surface region of Nd-TiO₂ calcined at high temperatures can be tuned by changing the amount of Nd₂O₃. Based on the results from XPS, EDX, XRD, and UV Raman spectra, it is assumed that Nd³⁺ ions do not enter the TiO₂ lattice, but highly disperse onto the Nd-TiO₂ particle surface in the form of Nd₂O₃ crystallites. These crystallites inhibit the agglomeration, growth in crystal size, and anatase-to-rutile phase transformation of TiO₂. In the photocatalytic degradation of RhB reaction, Nd-TiO₂ nanoparticles with higher surface area and wider optical response are more reactive in case of the same surface anatase phase. When the mixed phases of anatase and rutile exist in the surface region of Nd-TiO₂, the synergetic effect over surface area and optical response is the important parameter which determines optimal photocatalytic activity.     

紫外-可见光催化活性的硫酸铵改性含钛高炉渣光催化剂的制备(英文)

以含钛高炉渣和硫酸铵为原料,利用高能球磨法制备硫酸盐掺杂的含钛高炉渣(STBBFS)光催化剂。利用X射线光电子能谱(XPS)、X 射线衍射(XRD)、扫描电镜(SEM)、紫外-可见吸收光谱(UV-Vis)、热重(TGA)分析以及暗态吸附 Cr(VI)废水、光催化还原 Cr(VI)废水实验对 STBBFS 催化剂的物相、表面结构、光吸收能力、吸附容量以及光催化活性进行表征。结果表明:Cr(VI)在 STBBFS 催化剂表面上的吸附遵循 Langmuir 吸附等温线模型;掺杂硫酸盐后,STBBFS 催化剂的吸附容量增大为 8.25 mg/g;在 300 °C煅烧后,STBBFS 催化剂由于存在较高的钙钛矿含量、吸附容量及表面酸性,从而具有较高的光催化活性。     

二维BiOBr/g-C3N4光催化材料的构建及性能研究

高效、稳定光催化材料的开发是光催化技术应用的关键，以尿素、硝酸铋和溴化钾等为原料，通过一步水热法制备了BiOBr/g-C₃N₄(Bix/CN)光催化剂，结合紫外-可见吸收光谱结果计算出BiOBr和g-C₃N₄的导带位置在0.52和-1.1 eV，价带位置在3.38和1.55 eV处，光电催化及荧光测试中Bix/CN表现出较高的光电流和较低的电荷转移电阻，说明复合可有效降低光催化材料中电子-空穴的复合率，其中Bi3/CN在可见光辐射10 min下，对水溶液中罗丹明B的总去除率可达到81.35%，循环使用5次后对RhB的总去除率仅下降了6%。复合材料光催化效率的提高主要依赖于2种二维单体的有效耦合，光电催化和自由基捕获试验结果表明，g-C₃N₄导带上活性物种·O₂^-的有效生成是复合材料光催化性能提高的本质原因。     

Synthesis of iron（Ⅲ）-doped nanostructure TiO2/SiO2 and their photocatalytic activity

Iron(Ⅲ)-doped nanostructure TiO2-coated SiO2 (TiO2/SiO2) particles were prepared using the layer-by-layer assembly technique and their photocatalytic property was studied. TiO2 colloids were synthesized employing the sol-gel method with TiCl4 as a precursor. The samples were characterized by Fourier transform infrared spectroscopy (FTIR), SEM, EDS, XPS, and XRD. The experimental results show that TiO2 nanopowders on the surface of SiO2 particles are well distributed, the amount of TiO2 is increased with the adding of coating layers, the pure anatase-TiO2 coating layers are synthesized at 500℃, and the photocatalytic activity of Fe3 -doped TiO/SiO2 is higher than tnat of undoped TiO2/SiO2.     

Synthesis of iron(Ⅲ)-doped nanostructure TiO2/SiO2 and their photocatalytic activity

Iron(Ⅲ)-doped nanostructure TiO2-coated SiO2 (TiO2/SiO2) particles were prepared using the layer-by-layer assembly technique and their photocatalytic property was studied. TiO2 colloids were synthesized employing the sol-gel method with TiCl4 as a precursor. The samples were characterized by Fourier transform infrared spectroscopy (FTIR), SEM, EDS, XPS, and XRD. The experimental results show that TiO2 nanopowders on the surface of SiO2 particles are well distributed, the amount of TiO2 is increased with the adding of coating layers, the pure anatase-TiO2 coating layers are synthesized at 500℃, and the photocatalytic activity of Fe3+-doped TiO/SiO2 is higher than tnat of undoped TiO2/SiO2.     

Preparation and characterization of the TiO2-V2O5 photocatalyst with visible-light activity

Visible-light responsive TiO2-V2O5 catalyst was prepared using a binary sol-gel and in-situ intercalation method. The TiO2 sol and V2O5 sol were mixed to disperse the V2O5 species in the TiO2 phase at molecular level. The binary sol was then intercalated into interspaces of polyaniline （PANI） by means of in-situ polymerization of aniline. Conglomeration of the TiO2-V2O5 dusters during the calcination process was avoided because of the wrap of polyaniline. The surface mor- phology, the crystal phases, the structure, and the absorption spectra of （PANI）,/TiO2-V2O5 and the composite catalyst were studied using SEM, XRD, FT-IR, and UV-Vis. The photoactivity of the prepared catalyst under UV and visible light irradiation were evaluated by decolorization of methylene blue （MB） solution. The results showed that the composite catalyst displayed a homogeneous anatase phase, and the vanadium pentoxide species was highly dispersed in the TiO2 phase. The composite catalyst responded to visible light because of the narrowed band gap. In this study, the catalyst with the sol volume ratio of TiO2： V2O5 = 10：1 presented the best photocatalytic activity.     

Preparation and characterization of （metal, nitrogen）-codoped TiO2 by TiCl4 sol-gel auto-igniting synthesis

The nitrogen-doped and （metal, nitrogen）-codoped TiO2 photocatalysts （metal = Ag, Ce, Fe, La） were synthesized by sol-gel auto-igniting synthesis （SAS） with the complex compound sol of TiCl4-NH4NO3-citri acid-metal nitrate- NH3.H20 as a precursor. The products were characterized by means of XRD, XPS, and UV-Vis diffuse reflectance spectra, and their photocatalytic activity was investigated under visible light. It was found that all the synthesized powders showed good absorption for visible light, and that the radius and alterable valence states of doping metallic cations played important roles on their photocatalytic activity. These results were discussed in detail.     

制备方法对低温NH3-SCR催化剂Mn-La结构与性能的影响

采用固相反应法、共沉淀法制备了Mn-La复合氧化物催化剂,考察了制备方法对催化剂脱硝性能及抗SO₂/H₂O性能的影响。并通过XRD、BET、H₂-TPR、NH₃-TPD、XPS等手段对催化剂的结构和物理化学特性进行了表征。结果表明,La掺杂降低了MnO_x的结晶度,增大了催化剂的比表面积和孔体积。Mn-O-La键合作用促进了锰在催化剂表面的分散,而高分散的锰更容易被还原,催化剂的还原温度向低温方向迁移,氧化还原能力得到提高。掺杂La之后,催化剂表面Br?nsted酸和总酸量增加,同时Mn⁴⁺和表面化学吸附氧的浓度也得到提高。因此,La掺杂有利于促进催化剂的脱硝活性。反应评价结果表明,共沉淀法制备的MnLa-CPM催化剂表现出最佳的脱硝效率,在80 ℃时脱硝效率接近100%。在H₂O和SO₂存在的条件下,MnLa-CPM催化剂的脱硝效率仍能达到80%,表现出了较好的抗硫水性能。