Cu2O/Cu2S 复合材料制备及可见光催化降解甲基橙的研究

通过水热法制备Cu₂O/Cu₂S 复合材料对甲基橙(MO) 进行光催化降解实验。在Cu₂O 中引入S 元素, 通过 改变Cu/S 投加摩尔比, 从而得到不同Cu/S 的复合材料。利用XRD、SEM、UV-vis、EIS 等手段对材料进行表征, 并 对MO 进行光催化降解实验。XRD 结果表明, 随着S 含量的增多, Cu₂S 的衍射强度逐渐上升, Cu₂O 的f111g 晶面 衍射强度逐渐降低。SEM 结果表明Cu₂S 能较好地包覆在Cu₂O 八面体的表面。通过UV-vis 和EIS 结果计算得知, 复合材料带隙为1.49 eV, 电荷转移电阻大幅降低。降解实验结果表明复合材料最佳Cu/S 投加摩尔比为15 : 1, 其在 100 min 时对MO (100 mL, 10 mg/L) 降解率达到91.4%, 明显高于纯Cu₂O 对于MO 的降解率(60.3%)。猝灭实验表 明了?OH 和 ?O₂ ^-在光催化过程中起到主要作用。     

球形Cu2O@HP-β -CD 合成、表征及类芬顿去除水中亚甲基蓝的研究

利用液相沉淀法制备 Cu₂O@HP-β-CD, 通过 XRD、SEM、FT-IR 对 Cu₂O@HP-β-CD 的结构进行表征, 并研究其对亚甲基蓝 (MB) 的类芬顿催化降解性能。XRD 图谱显示样品的衍射峰为纯 Cu₂O, HP-β-CD 与 Cu 摩尔比为 1 : 1 时样品 SEM 形貌为 500 nm, 大小均一的球形。Cu₂O@HP-β-CD 类芬顿体系降解 MB 的实验结果表明, 当HP-β-CD 与 Cu 摩尔比为 1 : 1, 加入浓度为 20 mmol/L 的 H₂O₂, 100 min 时 MB 去除率达到 96.1%。相同条件下, 液相法单一合成的 Cu₂O 的 MB 去除率为 54.4%; Cu₂O@HP-β-CD 的一级动力学反应速率常数为 0.027 76 min^?1 , 高于 Cu₂O 的反应速度常数 (0.007 4 min^?1)。Cu₂O@HP-β-CD 的自由基捕获实验表明了·OH 在催化降解过程中起主要作用。     

水热辅助溶胶凝胶法制备纳米钛酸锌及其光催化性能

采用水热辅助的溶胶凝胶法制备纳米钛酸锌（ZnTiO₃）光催化剂,以罗丹明B为目标降解物,运用动力学模型分析罗丹明B（RhB）初始浓度对降解效果的影响。通过SEM、XRD、XPS、UV-Vis DRS对ZnTiO₃进行表征,并使用自由基捕获试验分析其降解机理。结果表明,ZnTiO₃为纯六方相,形貌为类球形,粒径50 nm左右。在催化剂用量为1 g/L、RhB初始浓度为5 mg/L、pH值为3的条件下,光催化反应150 min后,RhB降解率为93.2%。其动力学方程为k=0.132C₀^-1.253。ZnTiO₃光催化剂降解过程中,·OH、h⁺、·O₂^-均起到催化作用,产生·OH、h⁺的量相近且多于·O₂^-,说明·OH、h⁺在催化反应中起主要作用。     

沸石负载Mn,N共掺杂TiO2及光催化性能

为提高传统TiO₂光催化剂的可见光催化活性,本文采用溶胶-凝胶法合成了Mn,N共掺杂TiO₂光催化剂,改善了传统TiO₂光生载流子易复合的问题;进一步采用沸石作为载体对改性后的TiO₂样品进行负载,解决了传统光催化剂存在的难分离回收问题,以达到光催化剂可重复使用的目的.借助X-射线衍射仪、扫描电子显微镜、紫外分光光度计、傅立叶变换红外光谱仪等测试手段对Mn,N共掺杂TiO₂光催化剂的结构、元素组成、微观形貌和光催化降解性能进行系统分析与研究.研究结果表明,沸石负载Mn,N共掺杂TiO₂的样品较未改性的TiO₂样品具有更高的光催化降解活性,在可见光照射下,在最优掺杂条件下获得的TiO₂光催化剂在60 min内对孔雀石绿的降解率可达到97%,这主要归因于锰离子掺杂能够对TiO₂光生载流子的复合产生抑制作用,促进光生电荷分离,与此同时氮元素掺杂可有效拓宽TiO₂半导体光催化剂光响应范围.此外,经过5次循环使用后,对孔雀石绿的降解率没有较大程度的减弱,依然能够维持在88%以上,表明沸石负载Mn,N共掺杂TiO₂的样品具有较好的光催化循环稳定性.     

硅基高分散钴氧化物活化亚硫酸盐降解有机污染物的效能

近年来,基于硫酸根自由基（SO₄^·-）的高级氧化技术（SR-AOPs）迅速发展,高效稳定地产生SO₄^·-自由基的催化剂及相关机制成为新的研究重点。采用氨水改性吸附焙烧法制备非均相硅基高分散钴氧化物（CoNSi）催化剂,用于活化工业副产物亚硫酸盐（S（IV））,进而以废治污降解污染物。分别研究了不同pH值、不同CoNSi和亚硫酸钠（Na₂SO₃）投加量、不同橙黄Ⅱ（AO7）浓度以及氧气对底物降解效能的影响,分析了亚硫酸盐浓度和AO7浓度对AO7降解反应初始速率的影响。结果表明：当反应pH值为9.0,CoNSi和Na₂SO₃投加量分别为0.25 g/L和1.0 mM,AO7浓度为7 mg/L,氧气存在的条件下,AO7的降解率可达到79.4%。此外,序批实验证明了CoNSi活化亚硫酸盐的稳定性,自由基抑制实验证明了SO₄^·-自由基是降解AO7的主要活性物种。     

Pd纳米晶修饰TiO2纳米管阵列光电极的制备及性能

为提高TiO₂的可见光催化性能,采用阳极氧化法在Ti箔上原位生成TiO₂纳米管阵列,再利用阴极电沉积法制备了贵金属Pd纳米晶修饰的TiO₂纳米管阵列光电极,并利用扫描电子显微镜（SEM）、X-射线光电子能谱（XPS）及紫外-可见漫反射光谱（UV-vis DRS）对其表观形貌、表面形态及光吸收性能进行表征．结果表明:Pd纳米晶有效地修饰在TiO₂纳米管阵列的表面,且以Pd⁰形式存在．此外,Pd纳米晶修饰明显拓展了TiO₂纳米管阵列的可见光响应范围．以甲基蓝为模型污染物,重点考察阴极沉积电压及沉积时间对其光催化性能的影响．结果表明:阴极沉积电压为-0.8 V、沉积时间为10 min对甲基蓝的光催化降解效果最佳,且符合拟一级反应动力学模型．模拟太阳光下光照120 min对甲基蓝的降解率可达71.4％,是纯TiO₂纳米管阵列光电极的1.5 倍．     

可见光响应型(CuAg)xIn2xZn2(1-2x)S2光催化剂的光催化制氢

为实现可见光下分解水制氢,用沉淀煅烧法合成系列(CuAg)_xIn_2xZn2(1-2x)S₂光催化剂．采用X射线衍射仪(XRD)、紫外可见吸收光谱(UV-Vis)、电位粒径仪(DLS)、X射线能谱(EDS)、电感耦合等离子体质谱(ICP-MS)等方法研究了光催化剂的能带结构,评价其光催化性能．结果表明,随着组成配比x值的增加,光催化剂的光吸收从紫外光向可见光扩展,禁带宽度逐渐变小. 通过计算发现,光催化剂的导带电位逐渐接近氢的氧化还原电位．合成的(CuAg)_xIn_2xZn2(1-2x)S₂ (x=0.05~0.30)在可见光下都能光催化产氢,并且(CuAg)0.15In0.3Zn1.4S₂(即x=0.15)具有最高的光催化制氢活性．调节组成配比可调控光催化剂的能带结构,有助于获得具有高活性和稳定性的可见光响应型光催化剂．     

铜基材料的制备及其光催化还原CO2的实验研究

光催化还原技术可以将CO₂气体转化成高附加值有机物,实现CO₂资源化利用。TiO₂作为常见的光催化材料,具有价格低廉、化学稳定性高等优点。虽其自身的光谱响应范围较窄,且其电子空穴复合率太高,导致其作为光催化材料的催化效率大大降低,但可以通过半导体复合的方式提高其光催化性能。以硫脲和二水氯化铜团制备出硫化亚铜Cu₂S-TiO₂-X,通过高温水热复合到基体上,通过X射线衍射、X射线电子能谱、扫描电镜、紫外光可见光分度计等表征手段研究了其物理特性,并进行了CO₂还原实验。结果表明:Cu₂S-TiO₂-1.0的光催化还原性最强,其CH₄产率为0.12 μmol/(g·h);随着Cu₂S含量的减少,CH₄产率先增加后减少。     

TiO2/石墨烯复合材料的水热法合成与光催化性能

为了提高TiO₂的光催化性能,采用水热法一步制备了TiO₂/石墨烯(TiO₂/RGO)复合物．采用XRD、FT-IR、RS、UV-Vis DRS、TEM等测试方法对其进行了表征,并研究了不同质量比的复合物在可见光下对甲基橙(MO)的光催化降解．结果表明:在TiO₂/RGO复合物中,TiO₂以10 nm左右的颗粒均匀地分散在石墨烯层上;与在同等条件下制备的TiO₂相比,TiO₂/RGO复合物在可见光区吸收明显增强,吸收边缘红移了20 nm;质量比为1∶0.005的TiO₂/RGO复合物,2 h内的降解率达到74.79％．可见将石墨烯与TiO₂复合,能够有效地提高TiO₂的可见光催化性能．     

BiOI/g-C3N4协同光催化还原Cr(VI)及光降解罗丹明 B

通过一步液相法合成BiOI/g-C3N4复合光催化剂,利用XRD、IR和UV-vis DRS等手段表征产物的物相、结构 及其光电特性。研究BiOI/g-C3N4光催化剂在可见光激发下还原Cr(VI)和降解罗丹明B (Rh B)的光催化活性。结果表 明,在可见光光照下,BiOI/g-C3N4可将97.2%的Cr(VI)光还原成Cr(III),RhB的可见光降解率可达97.8%;与纯g-C3N4 相比,Cr(VI)转化率和RhB降解速率分别提高3.9和4.4倍。研究发现BiOI和g-C3N4存在协同光催化效应,光生电子还 原Cr(VI),而产生的空穴和·O2-共同作用氧化RhB。     

Biomolecule-assisted solvothermal synthesis and enhanced visible light photocatalytic performance of Bi<Subscript>2</Subscript>S<Subscript>3</Subscript>/BiOCl composites

Novel Bi₂S₃/BiOCl photocatalysts were successfully synthesized via a facile biomolecule-assisted solvothermal method and biomolecule L-cysteine was used as the sulfur source. The structures, morphology, and optical properties of the synthesized samples were characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Raman spectroscopy, transmission electron microscopy (TEM), and UV-vis diffuse reflectance spectroscopy (DRS). The presence of Bi₂S₃ in the Bi₂S₃/BiOCl composites could not only improve the optical properties but also enhance the photocatalytic activities for the degradation of Rhodamine B (RhB) under visible-light irradiation (λ > 420 nm) as compared with single Bi₂S₃ and BiOCl. Especially, the sample displayed the best performance of the photodegradation when the feed molar ratio of BiCl3 and L-cysteine was 2.4:1, which was about 10 times greater than that of pure BiOCl. The enhanced photocatalytic activities could be ascribed to the effective separation of photoinduced electrons and holes and the photosensitization of dye. Moreover, the possible photodegradation mechanism was also proposed, and the results revealed that the active holes (h⁺) and superoxide radicals (?O₂ ^?) were the main reactive species during photocatalytic degradation.     

NH2-UiO-66/BiOBr/Bi2S3光催化剂的合成及其光催化性能

采用溶剂热法制备NH₂-UiO-66/BiOBr/Bi₂S₃（UBB）三元复合光催化剂,利用X射线衍射（XRD）、扫描电镜（SEM）表征该催化剂的晶体结构和微观形貌,为了评价其光催化活性及稳定性,在可见光下催化降解有色染料亚甲基蓝（MB,20 mg/L）和罗丹明B（RhB,20 mg/L）。结果表明:NH₂-UiO-66的含量为2%时,UBB的光催化活性最好,对MB的降解率在60 min内达到93.5%,对RhB的降解率在30 min内达到98.3%;MB和RhB初始浓度提高到100 mg/L时,光催化降解率仍保持在70%以上;4次循环试验后,UBB的催化活性无明显降低。本文采用紫外可见漫反射光谱（UV-vis DRS）、荧光光谱（PL）和阻抗（EIS）的3种表征方法,分析UBB光催化性能变化的原因,并结合莫特-肖特基（M-S）曲线、活性物质捕捉实验结果,提出适用于UBB三元体系的双Z型电子转移机制。     

负载型光催化膜特征及氟伐他汀降解性能分析

为克服传统悬浮型光催化技术因催化剂分离困难而导致的水体二次污染问题,通过悬浮过滤方式将ZnIn_2S_4负载在超滤膜表面得到光催化膜.利用扫描电镜(SEM)、紫外-可见漫反射光谱分析(UV-Vis)、X射线光电子能谱分析(XPS)、X射线衍射图谱分析(XRD)对其进行表征并分析其超滤性能.以氟伐他汀为目标污染物,采用功率500 W,光强230 W/m~2的长弧氙灯为光源,考察不同负载量光催化膜在光照条件下对氟伐他汀的降解率.结果表明,随着ZnIn_2S_4负载量增加,光催化膜对紫外光和可见光的响应逐渐增强,表面Zn、In、S元素特征峰响应逐渐增强,ZnIn_2S_4六方相型特征衍射峰逐渐增大,膜表面形成了均匀的光催化功能层,膜面亲水性增强,纯水通量衰减得到缓解,对氟伐他汀的降解率明显提高.但是过量ZnIn_2S_4会在膜面发生堆叠团聚,降低催化剂利用率,进而影响催化效率.负载量为0.2 g的光催化膜表面ZnIn_2S_4光催化层均匀,能有效利用光源能量,催化活性高,节省物料,在光照条件下对氟伐他汀的降解率可高达94.75%,长期运行下具有良好的光催化稳定性.     

Characterization and photocatalytic activity of KSr<Subscript>2</Subscript>Nb<Subscript>5</Subscript>O<Subscript>15</Subscript> with tungsten bronze structure

Tungsten bronze (TB) type potassium strontium niobate KSr₂Nb₅O₁₅ was prepared by solid-state reaction method, and was characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and UV-vis diffuse spectrum. The photocatalyst shows high photocatalytic activity of photodegrading acid red G. The effects of photocatalyst dosage and initial concentration of acid red G on the photodegradation process were studied. The kinetics of photocatalytic degradation of acid red G by KSr₂Nb₅O₁₅ catalyst follows the first order reaction.     

Fabrication and photocatalytic activity of Ag<Subscript>3</Subscript>PO<Subscript>4</Subscript>-TiO<Subscript>2</Subscript> heterostructural nanotube arrays

To extend the absorption capability of TiO₂ into visible light region and inhibit the recombination of photogenerated electrons and holes, we put forward an effective strategy of the coupling of TiO₂ with a suitable semiconductor that possesses a narrow band gap. Meanwhile, Ag₃PO₄-TiO₂ heterostructural nanotube arrays were prepared by the two-step anodic oxidation to obtain the TiO₂ nanotube arrays and then by a deposition-precipitation method to load Ag₃PO₄. The samples were characterized by field emission scanning electron microscopy (FESEM), energy dispersive spectrometry (EDS), X-ray diffraction (XRD), and UV-vis diffuse reflectance spectroscopy (UV-vis DRS). The experimental results showed that Ag₃PO₄ nanoparticles were uniformly dispersed on the highly ordered TiO₂ nanotube arrays, which increased the visible-light absorption of TiO₂ photocatalyst. The photocurrent density and photocatalytic degradation of methyl orange indicated that the performance of Ag₃PO₄-TiO₂ heterostructural nanotube arrays was better than that of the TiO₂ nanotube arrays, which could be attributed to the effective electron-hole separation and the improved utilization of visible light.     

Synthesis of polypyrrole nanoparticles by microemulsion polymerization for photocatalysis

The photocatalytic properties of polypyrrole nanoparticles prepared by W/O microemulsion method were reported. During the photodegradation of Orange II and Methyl Orange as organic dyes in UV/H₂O₂ and UV irradiation systems using polypyrrole nanoparticles as photocatalyst, the latter performances special photocatalytic activity towards to above dyes in both UV and UV/H₂O₂ system. In detail, its photocatalytic activity is 5.17 and 4.82 times higher than normal polypyrrole composites in UV/Orange II and UV/MO system relatively. The size of polypyrrole nanoparticles characterized by TEM is 200–400 nm with good dispersity. The further measurement by accelerated surface area and porosimetry system shows such nanoparticles have a specific surface area of 1.47 m²/g compared to normal polypyrrole of 0.22 m²/g. This conjugated polymer characterized by FTIR spectroscopies before and after photocatalytic reactions shows reliable chemical stability. In addition, it holds excellent recovery ability and keeps up their catalytic activity within distinctive drop after six repeated utilization.     

Synthesis and photocatalytic property of the ZrO<Subscript>2</Subscript>/TiO<Subscript>2</Subscript> pillared laponite

The ZrO2/TiO2 pillared laponite (Ti-Zr-lap) photocatalysts were prepared with intercalation reaction by supercritical fluid drying (SCFD),and characterized by XRD,TEM,SEM and BET surface area analysis,and the photocatalytic properties of Ti-Zr-lap were investigated by degradation of azo dye acid red B (ARB).The results showed that the ZrO2/TiO2 pillared structures in laponite could be formed,with the mass fraction of (Zr4++Ti4+)/laponite (Xm) increasing,the basal spacing and the BET surface area of Ti-Zr-lap significantly increased.The Ti-Zr-lap used as photocatalyst had the advantages of stable and porous layered structure,large surface area with the anatase type TiO2.Compared with the Ti-Zr-lap dried by air drying,the Ti-Zr-lap dried by SCFD showed better photocatalytic property which was very close to that of P25 TiO2.Using the Ti-Zr-lap as photocatalyst with the optimum Xm of 0.16 and the calcination temperature of 500 ℃,under the conditions of the initial concentration of ARB 20 mg/L,photocatalyst concentration of 1.5 g/L and irradiation time 60 min,the decoloring rate of ARB could achieve 98.3%,indicating that the Ti-Zr-lap had excellent photocatalytic property.