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.     

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.     

Construction of g-C3N4 nanotube/Ag3PO4 S-scheme heterojunction for enhanced photocatalytic oxygen generation

Heterojunction engineering is considered as a hopeful approach to ameliorate the separation of photogenerated carriers of photocatalysts, realizing efficient water-splitting performance. In this study, an organic-inorganic S-scheme of a one-dimensional g-C₃N₄ nanotube (TCN)/Ag₃PO₄ photocatalytic system with high photocatalytic water oxidation activity was designed by coupling g-C₃N₄ nanotubes over Ag₃PO₄ particles through a chemical coprecipitation method. The TCN/Ag₃PO₄ heterojunction demonstrated excellent photocatalytic O₂ production with an O₂ evolution rate of up to 370.2 μmol·L^?1·h^?1. X-ray photoelectron spectroscopy analysis showed that electron migration between TCN and Ag₃PO₄ led to the formation of an internal electric field pointing from TCN to Ag₃PO₄, which drove the S-scheme charge transfer mode between TCN and Ag₃PO₄. Accordingly, the TCN/Ag₃PO₄ heterojunction possessed fast charge separation and high redox ability, leading to high photoactivity and photostability. This research provides a new strategy for fabricating highly efficient inorganic-organic S-scheme photocatalysts for O₂ production.     

One-dimensional spindle-like BiVO4/TiO2 nanofibers heterojunction nanocomposites with enhanced visible light photocatalytic activity

One-dimensional spindle-like BiVO₄/TiO₂ nanofibers heterojunction nanocomposites with high visible light photocatalytic activity have been successfully obtained by combining the electrospinning technique and solvothermal method. The as-obtained products were characterized by field emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), UV–vis spectra and photoluminescence (PL) spectra. The results revealed that spindle-like BiVO₄ nanostructures were successfully grown on TiO₂ nanofibers. Photocatalytic tests showed that the BiVO₄/TiO₂ nanofibers heterojunction nanocomposites showed enhanced visible light photocatalytic activity than that of pure TiO₂ nanofibers, which might be attributed to the effective photogenerated electrons-holes separation based on the photosynergistic effect of the BiVO₄/TiO₂ heterojunction. Moreover, the BiVO₄/TiO₂ nanofibers heterojunction nanocomposites could be easily recycled without any decrease of the photocatalytic activity.     

Z-scheme AgSCN/Ag3PO4/C3N4 heterojunction with excellent photocatalytic degradation of ibuprofen

To develop a novel photocatalyst with high catalytic performance under sunlight, AgSCN/Ag₃PO₄/C₃N₄ heterojunction photocatalyst with Z-mechanism has been prepared, which demonstrates excellent photocatalytic performance for ibuprofen degradation. The catalytic activity of AgSCN/Ag₃PO₄/C₃N₄ is 1.5 and 3.3 times that of AgSCN/Ag₃PO₄ and Ag₃PO₄, respectively. The cyclic degradation number of AgSCN/Ag₃PO₄/C₃N₄ increases to seven because of the protection of AgSCN and C₃N₄ to Ag₃PO₄. The excellent photocatalytic performance of the AgSCN/Ag₃PO₄/C₃N₄ is attributed from the Z-mechanism with efficient separation efficiency of electron hole pair.     

Enhanced photocatalytic activity of La1-xSrxCoO3/Ag3PO4 induced by the synergistic effect of doping and heterojunction

This study sought to design and synthesize a series of perovskite-based La_1-xSr_xCoO₃/Ag₃PO₄ (with x = 0–1) heterojunction photocatalysts with different Strontium (Sr) doping contents by a simple sol-gel method and properties of the material were comprehensively characterized. Moreover, tetracycline (TC) was chosen as the target pollutant to assess the effect of Sr doping on the catalytic performance of LaCoO₃/Ag₃PO₄. Our results demonstrated that the partial replacement of La³⁺ with Sr²⁺ coupled with shifting Co³⁺ to the mixed-valence state of Co³⁺-Co⁴⁺ led to the formation of substantially more oxygen vacancies in the crystal lattice of La_1-xSr_xCoO₃/Ag₃PO₄. Therefore, the doped catalyst La_1-xSr_xCoO₃/Ag₃PO₄ exhibited enhanced photocatalytic performance. When x = 0.9, the obtained La_0·1Sr_0·9CoO₃/Ag₃PO₄ exhibit an optimal performance for TC degradation. Kinetic analyses demonstrated that the degradation rate constant of TC in La_0·1Sr_0·9CoO₃/Ag₃PO₄ system was 0.0098 min^?1, which is 1.78 times that of LaCoO₃/Ag₃PO₄, and 2.45 times that of SrCoO₃/Ag₃PO₄. Additionally, free radical sequestration experiments indicated that OH^?, h⁺, and O₂^?? all participated in the degradation of TC in the following order: h⁺>O₂^??>OH^?. Finally, analyses of photocatalytic mechanisms suggested that the enhanced photocatalytic activity of La_0·1Sr_0·9CoO₃/Ag₃PO₄ was due to its strong electron transfer properties and the formation of substantially more surface oxygen vacancies in Sr-doped La_0·1Sr_0·9CoO₃.     

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.     

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.     

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.     

The stabilization effect of surface capping on photocatalytic activity and recyclable stability of Ag3PO4

We find the stabilization effect of surface capping on the adsorption capacity and photocatalytic activity of Ag₃PO₄ in the recycling. The citrate anion complex (CAC) as the surface capping is confirmed to be constituted by citrate anion and silver citrate complex. The adsorption capacity of Ag₃PO₄ with CAC capping exhibits little increase in the subsequent cycle, whereas the one of the bare Ag₃PO₄ decreases by 25.8% for methylene blue (MB). The photocatalytic activity of Ag₃PO₄ with CAC capping is maintained, compared to marked 10% decrease of bare Ag₃PO₄ for degrading MB.     

Preparation and characterization of Ag3PO4/BiOI composites with enhanced visible light driven photocatalytic performance

Ag₃PO₄/BiOI composites were successfully prepared by a facial room temperature liquid phase method. Ag₃PO₄ nanoparticles were uniformly distributed on the surface of BiOI nanosheets. The photodegradation tests show that the photocatalytic efficiency was increased at first and then decreased when further increasing Ag₃PO₄ content in the composites. The best photocatalytic performance was obtained for the sample with Ag/Bi ratio of 0.3 and the photodegradation efficiency of Ag₃PO₄/BiOI was nearly 10 times that of BiOI. The enhanced photocatalytic activity of the composites was due to the improved photogenerated carrier separation capacity, being induced by the coupling effects of the two semiconductors.     

Porous Ag3PO4 microtubes with improved photocatalytic properties

The Ag₃PO₄ porous microtubes are, for the first time, prepared by a one-pot synthesis using polyethylene glycol 200 (PEG200) as the reaction medium. This study establishes that PEG 200 plays a vital role in the formation of the unique structures. Under visible light irradiation (≥ 420 nm), the porous sample exhibits a higher photocatalytic activity for the degradation of RhB than solid Ag₃PO₄ and Ag₃PO₄ tetrapods, which has been mainly ascribed to the novel hollow structure.     

Ultrasound-assisted synthesis of high-efficiency Ag3PO4/CeO2 heterojunction photocatalyst

The Ag₃PO₄/CeO₂ heterojunction photocatalyst prepared by an ultrasound-assisted method exhibits an enhanced photocatalytic activity compared to pure Ag₃PO₄, CeO₂, and Ag₃PO₄/CeO₂ obtained without ultrasound action. The samples were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), and ultraviolet–visible absorption spectroscopy (UV–vis), and the effects of ultrasound on the physicochemical properties and photocatalytic activity of Ag₃PO₄/CeO₂ are discussed. Results show that the ultrasound-assisted synthesis method significantly improves the photocatalytic ability. The mechanism about the improvement was discussed in details.     

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。     

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...     

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.     

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。     

Controlled synthesis of Bi2O3/BiOBr/Zn2GeO4 heterojunction photocatalysts with enhanced photocatalytic activity

BiOBr/Zn₂GeO₄ heterojunctions decorated by Bi₂O₃ quantum dots (QDs; named as Bi₂O₃/BiOBr/Zn₂GeO₄ hereafter) with intriguing micro/nanostructures have been constructed via a two‐step hydrothermal route. The compositions, phases, and morphologies of Bi₂O₃/BiOBr/Zn₂GeO₄ were investigated in detail. The light absorption ability, photocurrent responses, and photocatalytic degradation of methylene blue (MB) experiments were performed to evaluate the photocatalytic activity of the micro/nanoheterostructured Bi₂O₃/BiOBr/Zn₂GeO₄, which present a degradation efficiency of 88% after 240 minutes under light irradiation (λ = 300‐600 nm) over 100 mg Bi₂O₃/BiOBr/Zn₂GeO₄ in a 100 mL, 4 mg/L MB solution. The photocatalytic performance could be retained for at least four runs, indicating its excellent reusability for the degradation of MB in aqueous solution. It is found that the photodegradation of MB over Bi₂O₃/BiOBr/Zn₂GeO₄ is mainly ascribed to a hole oxidation mechanism in combination with a superoxide oxidation process. The high photocatalytic performance of Bi₂O₃/BiOBr/Zn₂GeO₄ upon UV light irradiation can be attributed to the effective charge separation and smoothly transferring of the photogenerated charge carriers throughout the heterojunction. The feasible strategy of preparing Bi₂O₃/BiOBr/Zn₂GeO₄ ternary composites is also of benefit to fabricate other efficient heterojunction catalysts with specific morphologies and properties.     

Ag/g-C3N4 photocatalysts: Microwave-assisted synthesis and enhanced visible-light photocatalytic activity

Ag/g-C₃N₄ photocatalysts were synthesized by a rapid microwave-assisted polyol process. The characterization results showed monodisperse Ag nanoparticles with diameters of a few nanometers closely attached to the edges of g-C₃N₄. The presence of Ag nanoparticles in Ag/g-C₃N₄ photocatalysts enhanced the visible-light absorption and suppressed the recombination of photogenerated electron/hole pairs. The Ag/g-C₃N₄ photocatalysts exhibited the superior visible-light responsive photocatalytic activity for rhodamine B degradation. The mechanism of visible-light induced photocatalysis over Ag/g-C₃N₄ photocatalysts was also discussed.