Novel NiTiO3/Ag3VO4 composite with enhanced photocatalytic performance under visible light

A novel NiTiO₃/Ag₃VO₄ composite with type-II band alignment was prepared using a modified Pechini/precipitation method. The FESEM image of the NiTiO₃/Ag₃VO₄ heterostructure reveals the dispersion of small NiTiO₃ particles on the Ag₃VO₄ surfaces, indicating the close interfacial connection between NiTiO₃ and Ag₃VO₄. The heterojunction shows remarkably higher photocatalytic activity than pure NiTiO₃ and Ag₃VO₄ due to an increase in light harvesting efficiency and an efficient electron–hole separation being induced by the suitably matching conduction and valence band levels. Based on the VB-XPS and UV–vis DRS results, a possible electron–hole transfer mechanism at the NiTiO₃/Ag₃VO₄ interface is proposed.     

Ag3PO4/g-C3N4复合材料的制备及其光催化性能

以硝酸银和三聚氰胺为原料,采用原位沉淀法制备了Ag3PO4/g-C3N4复合材料,利用XRD、SEM、TEM、UV-Vis DRS和PL等技术对其进行了表征.结果显示,g-C3N4呈二维片状结构,Ag3PO4为立方晶相的类球状结构,且均匀分布在g-C3N4表面.以亚甲基蓝(MB)为模拟污染物,考察g-C3N4与Ag3P...     

Ag3PO4/g-C3N4复合材料制备及其光催化性能

采用原位沉淀法制备了Ag3PO4/g-C3N4复合材料，利用XRD、SEM、TEM、UV-Vis DRS和PL等技术对其进行表征。结果显示，g-C3N4呈现二维片状结构，Ag3PO4为立方晶相的类球状结构，且均匀分布在g-C3N4表面。以亚甲基蓝（MB）为模拟污染物，考察g-C3N4与Ag3PO4的不同摩尔比对MB降解率的影响。结果表明，在Ag3PO4/g-C3N4的摩尔比为1:0.7时，Ag3PO4/g-C3N4复合材料的光催化活性最佳，可见光照30 min后MB降解率即达到100%。光催化剂稳定性较好，重复使用5次，MB降解率仍达到85.24%。降解机理研究表明，h 和e-是降解MB的主要活性物质。     

A g-C3N4 supported graphene oxide/Ag3PO4 composite with remarkably enhanced photocatalytic activity under visible light

In this work, a ternary composite photocatalyst of graphitic carbon nitride (g-C₃N₄), graphene oxide (GO), and Ag₃PO₄ was prepared through a simple precipitation route, in which Ag₃PO₄ nanoparticles covered or wrapped with GO sheets are supported on g-C₃N₄ sheets. The composite photocatalyst displays enhanced absorption in the visible region, and exhibited superior photocatalytic activity compared with single-component or binary composite photocatalysts in the photocatalytic decomposition of Rhodamine B. The enhancement of photocatalytic activity could be attributed to the synergistic effect among them. The ternary composite also exhibited enhanced stability, but further efforts should be made to make it more stable.     

Novel BiOI/BiOBr heterojunction photocatalysts with enhanced visible light photocatalytic properties

A novel heterojunction photocatalyst BiOI/BiOBr was synthesized by a simple modified deposition–precipitation method. Several characterization tools including XRD, SEM, HRTEM and UV–vis DRS were employed to study the phase structures, morphologies and optical properties of the samples. BiOI/BiOBr exhibited higher photocatalytic activity than single BiOI and BiOBr for the degradation of methyl orange (MO) under visible light (λ > 420 nm). This result can be due to the formation of the heterojunction between BiOI and BiOBr, which can separate photogenerated carriers efficiently. The photocatalytic mechanism study demonstrates that O₂⁻ and h⁺ are the main reactive species while OH can be negligible.     

Ag3PO4/Bi2WO6 hierarchical heterostructures with enhanced visible light photocatalytic activity for the degradation of phenol

The Ag₃PO₄/Bi₂WO₆ hierarchical heterostructures were prepared by a combination of hydrothermal technique and in situ precipitation method for the first time. The Ag₃PO₄/Bi₂WO₆ hierarchical heterostructures displayed enhanced visible-light photocatalytic activity against phenol. The enhanced photocatalytic activity could be attributed to the effective separation of photogenerated carriers driven by the photoinduced potential difference generated at the Ag₃PO₄/Bi₂WO₆ heterojunction interface. Repetitive tests showed that the Ag₃PO₄/Bi₂WO₆ hierarchical heterostructures maintained high catalytic activity over several cycles, and it had a better regeneration capability under mild conditions.     

g-C3N4/Bi2MoO6/Ag3PO4复合材料制备及其可见光催化性能

以三聚氰胺、二水合钼酸钠和五水合硝酸铋为原料,采用溶剂热法制备了g-C3N4/Bi2MoO6前驱体,然后通过共沉淀法将Ag3PO4纳米粒子负载在前驱体上,得到g-C3N4/Bi2MoO6/Ag3PO4复合材料。通过XRD、FTIR、XPS、SEM、UV-Vis DRS等对复合材料进行表征。结果表明,g-C3N4、Bi2MoO6和Ag3PO4之间形成了异质结结构,促进光生电子-空穴对的有效分离。以盐酸四环素（TC）为目标降解物,分析材料的光催化活性。在可见光照射下,30 mg g-C3N4/Bi2MoO6/Ag3PO4在50 min内对40 mL 10 mg/L的TC溶液的降解率达到93%。降解速率常数为0.033 min-1,分别是g-C3N4、Bi2MoO6和Ag3PO4降解速率常数的33倍、3.6倍和1.5倍;g-C3N4/Bi2MoO6/Ag3PO4对TC进行降解,循环利用4次后,对TC的降解率为71%,说明g-C3N4/Bi2MoO6/Ag3PO4具有较好的稳定性。自由基捕获实验结果表明,g-C3N4/Bi2MoO6/Ag3PO4光催化降解TC的主要活性物种为·OH和·O2-。最后提出了TC可能的降解机理和降解路径。     

Study on improving visible light photocatalytic activity of Ag3PO4 through morphology control

Improving the visible light activity of Ag₃PO₄ photocatalyst through morphology control was studied using a precipitation synthetic method. It was found that the morphology depended on the reactants' constitution. With its alteration, polyhedral microcrystals, spherical and irregular nanocrystals were obtained, respectively. Among them, the polyhedrons exhibited the highest efficiency in degrading methylene blue. This was attributed to the higher visible-light absorption efficiency and more effective electron–hole separation ability of the polyhedrons, according to UV–visible diffuse reflectance spectroscopy (UV–vis DRS) and photoluminescence (PL) investigation.     

Highly efficient and stable Ag/Ag3PO4 plasmonic photocatalyst in visible light

A highly efficient and stable photocatalyst Ag/Ag₃PO₄ was prepared by the ion-exchange process between AgNO₃ and Na₂HPO₄ and subsequently light-induced reduction route. The diffuse reflectance spectra (DRS) indicated Ag/Ag₃PO₄ had strong absorption in UV and visible-light regions. The composite showed excellent visible-light-driven photocatalytic performance. It can decompose organic dye within several minutes and still maintain a high level activity even though used five times. It is considered that this excellent performance results from the surface plasmon resonance of Ag nanoparticles and a large negative charge of PO₄^3 − ions.     

NiTiO3/Ag3PO4 composites with improved photocatalytic activity under visible-light irradiation

A series of NiTiO₃/Ag₃PO₄ composites were prepared by a simple ion-exchange deposition method. The composition and morphology of the samples were determined by XRD, EDS and SEM. UV–vis DRS was used to characterize their optical absorption properties. The loading of NiTiO₃ could promote the efficient separation of photoinduced electron-hole pairs and enhance the charge carrier transport to improve the photocatalytic activity. The APO-5 composite exhibited the best photocatalytic activity for the degradation of methyl violet (MV). Kinetics studies indicated that the APO-5 composite showed an apparent rate constant of 0.115 min⁻¹, which was 2.61 times that of pure Ag₃PO₄.     

钨酸锌/磷酸银复合光催化剂的制备及光催化性能

采用水热法合成钨酸锌（ZnWO₄）粉体,再通过原位沉淀法将磷酸银（Ag₃PO₄）聚集于ZnWO₄表面制备ZnWO₄/Ag₃PO₄复合光催化剂。通过罗丹明B光催化降解实验,探讨Ag₃PO₄含量对ZnWO₄ /Ag₃PO₄材料光催化性能的影响。结果表明,当复合粉体中Ag₃PO₄质量分数超过40%时,其光催化性能比单一成分的Ag₃PO₄催化剂更优。Ag₃PO₄质量分数为50%时,复合材料的光催化性能最佳,循环使用5次后其光催化效率仍可达到90%以上。     

贝壳粉/BiOI复合光催化剂制备及性能研究

采用溶剂热法制备了不同质量百分比的贝壳粉/BiOI复合光催化剂,利用X射线衍射、扫描电镜、紫外可见漫反射光谱对其进行了表征,与此同时对其在可见光条件下光催化性能进行了测试。结果表明,贝壳粉/BiOI复合催化剂的催化性能较BiOI的催化性能显著提高,且当贝壳粉的质量百分数为3%时,复合催化剂的催化活性最高。     

Fabrication and characterization of CdS/BiVO4 nanocomposites with efficient visible light driven photocatalytic activities

Novel CdS/BiVO₄ nanocomposites were synthesized by simple solvothermal method. The as-prepared samples were characterized by transmission electron microscopy (TEM), scanning electron microscopy (FE-SEM), X-ray diffraction (XRD), Raman spectroscopy, UV–vis diffuse reflectance spectra (DRS), Fourier transform infrared spectra (FT-IR) and photoluminescence (PL). In the nanocomposites, CdS particles were deposited on the surface of the BiVO₄. The photocatalytic tests showed that the CdS/BiVO₄ nanocomposites possessed a higher rate for degradation of malachite green (MG) than the pure BiVO₄ under visible light irradiation. The 1.5-CdS/BiVO₄ nanocomposite photocatalyst was found to degrade 98.3% of MG under visible light irradiation. Moreover, the photocatalytic mechanism of CdS/BiVO₄ nanocomposites was also discussed. The results showed that the nanocomposite construction between CdS and BiVO₄ played a very important role in their photocatalytic properties, which has the potential application in solving environmental pollution issues utilizing solar energy effectively.     

Ag3PO4 quantum dots sensitized AgVO3 nanowires: A novel Ag3PO4/AgVO3 nanojunction with enhanced visible-light photocatalytic activity

Ag₃PO₄/AgVO₃ heterojunctions with high photocatalytic activities were synthesized via a simple and practical low-temperature solution-phase route by using AgVO₃ nanowires as substrate materials. The as-prepared Ag₃PO₄/AgVO₃ heterojunctions included Ag₃PO₄ quantum dots assembling uniformly on the surface of AgVO₃ nanowires. Compared with pure AgVO₃ nanowires, Ag₃PO₄/AgVO₃ composite photocatalysts exhibited enhanced photocatalytic activities under visible light irradiation in the decomposition of 4-chlorophenol (4-CP) ethanol solution. The enhanced performance is believed to be induced by the high specific surface area, strong visible-light absorption originating from the quantum dot sensitization of Ag₃PO₄, and high efficient separation of photogenerated electron–hole pairs through Ag₃PO₄/AgVO₃ heterojunction.     

WO3/C/Ag3PO4复合材料光催化降解双酚A

以磷酸法制备的活性炭、WO3、AgNO3、Na2HPO4?12H2O为原料,采用共沉淀法制备WO3与C不同含量的系列WO3/C/Ag3PO4复合材料.采用XRD、FTIR、XPS、SEM、TEM和固体紫外漫反射(UV-DRS)技术对其进行了结构表征.在可见光照射下,以双酚A(BPA)模拟污染物,评价WO3/C/Ag3P...     

Synthesis of cube-like Ag/AgCl plasmonic photocatalyst with enhanced visible light photocatalytic activity

Cube-like Ag/AgCl plasmonic photocatalyst was successfully synthesized through a one-pot precipitation method by simply adding an aqueous solution of AgNO₃ into the natural hot spring, wherein the hot spring acted as the chlorine source. The cube-like Ag/AgCl with a size of 0.5–0.9 μm exhibited enhanced visible light photocatalytic performance for the degradation of organic MO dye due to the localized surface plasmon resonance (LSPR) of the photoexcited Ag species. The trapping experiments confirmed that O₂⁻ and h⁺ were the main active species during the photocatalytic process.     

Preparation of Cu2O/exfoliated graphite composites with high visible light photocatalytic performance and stability

Cu₂O/exfoliated graphite composites (Cu₂O/EG (1 wt%), Cu₂O/EG (4 wt%), Cu₂O/EG (7 wt%), Cu₂O/EG (10 wt%), and Cu₂O/EG (15 wt%)) were prepared by the precipitation method. The photocatalytic activity of the material was evaluated using the decolorization of methyl orange (MO) solution as model reaction. Results showed that Cu₂O deposited on the worm-like flakes of EG in the form of nanocrystals. The EG provided a three-dimensional environment for photocatalytic reaction and endowed a high adsorption capacity for the sample. Under optimal conditions, the decolorization efficiencies of MO for 60 min reached 96.7%. Recycling of the catalyst showed Cu₂O/EG composites (10 wt%) to possess high photocatalytic efficiency even when repeatedly used for five times.     

Dual Z-scheme heterojunction g-C3N4/Ag3PO4/AgBr photocatalyst with enhanced visible-light photocatalytic activity

Recently, there has been a significant interest in developing high-performance photocatalysts for removing organic pollutants from water environment. Herein, a ternary graphitic C₃N₄ (g-C₃N₄)/Ag₃PO₄/AgBr composite photocatalyst is synthesized using an in-situ precipitation-anion-exchange process and characterized by several spectroscopic and microscopic techniques. During the photocatalytic reaction, X-ray photoelectron spectroscopy clearly illustrated the formation of metallic Ag on the g-C₃N₄/Ag₃PO₄/AgBr composite surface. The ternary composite photocatalyst demonstrated an increased photoactivity under visible light (>420 nm), achieving a complete decolorization of methyl orange (MO) in 5 min. The ternary g-C₃N₄/Ag₃PO₄/AgBr hybrid was also applied to the 2-chlorophenol degradation under visible light, further confirming its excellent photocatalytic activity. In addition, quenching experiments revealed that holes (h⁺) and O₂^?– were the major attack species in the decolorization of MO. The enhanced photoactivity of g-C₃N₄/Ag₃PO₄/AgBr results from the efficient transfer/separation of photoinduced charges with the dual Z-scheme pathway and the charge recombination sites on the formed Ag particles.     

Preparation of cerium and nitrogen co-doped titania hollow spheres with enhanced visible light photocatalytic performance

N,Ce-codoped titania hollow spheres were prepared using carbon spheres as template and using N,Ce-codoped titania nanoparticles as building blocks. The N,Ce-codoped titania nanoparticles were synthesized at low temperature. The prepared hollow spheres were characterized by X-ray diffraction (XRD), transmission electron microscope (TEM), X-ray photoelectron spectroscopy (XPS) and UV-Vis diffuse reflectance spectrum (DRS). The effect of N and Ce content on the physical structure and photocatalytic properties of the as-prepared hollow sphere samples was investigated. The mechanism of photocatalytic degradation of dyes under visible light irradiation was also discussed.