Fabrication and photocatalytic performance of one-dimensional Ag3PO4 sensitized SrTiO3 nanowire

The 1D Ag₃PO₄ sensitized SrTiO₃ nanowires are prepared by simple route of electrospinning-in situ deposition technique. The results of the thermogravimetry (TG), X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive Spectrometer (EDS), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS) and UV–Visible diffuse reflectance spectroscopy (UV–Vis) indicate that the Ag₃PO₄ nanoparticles has been deposited on the surface of the SrTiO₃ nanowires successfully. Experimental results showed that compared with pure SrTiO₃, the as-prepared 1D Ag₃PO₄ sensitized SrTiO₃ nanowires exhibit obvious enhancement of photocatalytic performance and stability. Especially, the Ag₃PO₄/SrTiO₃ (3AS sample) had a satisfactory photocatalytic activity for degrading methylene blue (MB) more than 98% under visible light irradiation. As to pure SrTiO₃ and Ag₃PO₄, only 9.8% and 49% of MB was decomposed after 35?min irradiation respectively. Furthermore, the mechanism of the enhancing photocatalytic activity could be ascribed to the nano-heterojunction of the Ag₃PO₄/SrTiO₃, the visible light response of the Ag₃PO₄, and the 1D structure of the nanowires.     

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.     

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.     

Photocatalytic activity of Ag3PO4 and some of its composites under non-filtered and UV-filtered solar-like radiation

Silver phosphate is a promising photocatalyst since its energy band gap is situated in the visible range (E_g≈2.4 eV), thus this material is a potential candidate for replacing titania which is photoactive only under UV. However, Ag₃PO₄ suffers of photocorrosion and therefore composites should be prepared to limit this detrimental effect. In this work, pure Ag₃PO₄ and its composites with AgI, TiO₂, and hydroxyapatite were prepared by using various methods. The photoactivity of the materials was evaluated by their ability to decolorize methylene blue and to mineralize phenol under non-filtered and UV-filtered artificial solar-like radiation. The use of UV cut-off filter enhanced the photocatalytic activity of pure silver phosphate by limiting the photocorrosion of silver(I) into Ag°. For composites with AgI and TiO₂, despite their lower photoactivity compared to pure Ag₃PO₄, the efficiency in mineralization of phenol after repeated run is stabilized by using UV cut-off filter. On the other hand, the photocatalytic efficiency of Ag₃PO₄ composites containing hydroxyapatite remained low mainly due to high absorption properties of hydroxyapatite. The photoactive samples showed excellent photoinduced antimicrobial properties where Gram-negative E. coli was more susceptible to photocatalytic deactivation than Gram-positive S. aureus (MRSA).     

Synthesis,performance and action mechanism of carbon black/Ag3PO4 photocatalysts

Novel carbon black (CB)/Ag₃PO₄ compound photocatalysts were synthesized from a hydrothermal method and characterized by X-ray diffraction, X-ray photoelectron spectroscopy, transmission electron microscopy and electrochemical methods. The photocatalytic oxidation ability of CB/Ag₃PO₄ was evaluated through methyl orange degradation experiments under visible light irradiation. The CB/Ag₃PO₄ showed higher photocatalytic activity than pure Ag₃PO₄. It was indicated the compound catalysts could absorb and utilize more optical energy to improve the photocatalytic activity, which was attributed to the ability of carbon black to accelerate the electron-hole separation. In particular, the methyl orange photocatalytic degradation rate over the 7?mg/L CB/Ag₃PO₄ was 1.6 times that of Ag₃PO₄. And the results of the cyclic experiment show that the photocatalyst has good stability. Moreover, the mechanism about the photocatalytic activity of CB/Ag₃PO₄ compounds was investigated. In this photocatalytic reaction, ?OH was the major active substrate responsible for the visible-light-driven degradation.     

Photocatalytic degradation of bisphenol A and dye by graphene-oxide/Ag3PO4 composite under visible light irradiation

A facile, one-step synthesis of graphene-oxide (GO)/Ag₃PO₄ was prepared. The as-prepared samples were characterized by scanning electron microscopy (SEM), energy dispersive spectrometer (EDS), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), diffuse reflectance spectroscopy (DRS) and fourier transformed infrared (FT-IR) spectroscopy. The SEM image indicated that Ag₃PO₄ particles were mainly distributed on the surface of GO sheets uniformly. DRS analysis revealed that the samples had good visible light response. The photocatalytic activity of the composites was evaluated by the degradation of Rhodamine B (RhB) and Bisphenol A (BPA). The results indicated that the photocatalytic performance of GO/Ag₃PO₄ was greatly enhanced after introduction of GO. The photocatalytic degradation efficiency of colorless chemical pollutants (BPA) over GO/Ag₃PO₄ was higher than that of Ag₃PO₄, and the possible degradation path was proposed by liquid chromatography mass spectrometry (LC-MS) analysis. Moreover, the photocatalytic stability was discussed by XRD and FT-IR spectroscopy analysis. Based on the experimental results, a possible visible-light photocatalytic degradation mechanism was also discussed.     

Facile synthesis of Ag3PO4 with the assistance of N,N-dimethylformamid and urea for high performance photocatalysis

Ag₃PO₄ was synthesized with the assistance of N, N-dimethylformamid (DMF) and urea for high performance photocatalysis. The photocatalytic activity of the as-synthesized samples was evaluated by photodegrading rhodamine B (Rh B) under visible light irradiation. As a result, the optimal Ag₃PO₄ synthesized with the assistance of DMF and urea exhibited enhanced photocatalytic activity for Rh B degradation under visible light irradiation. DMF and urea play vital roles in improving the photocatalytic activity of Ag₃PO₄. This study could provide a new perspective for the controllable synthesis of Ag₃PO₄.     

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.     

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.     

Synthesis of Ag3PO4–ZnO nanorod composites with high visible-light photocatalytic activity

Ag₃PO₄ nanoparticles with 50–100 nm in size distributed on the surface of ZnO nanorods with ca. 20 nm in diameter and 1–2 μm in length have been synthesized by a facile method. The Ag₃PO₄–ZnO nanorod composites had much higher photocatalytic activity toward degradation of Rhodamine B (RhB) under visible light irradiation than pure ZnO nanorods, and had better recyclability and stability than pure Ag₃PO₄ nanoparticles. The Ag₃PO₄–ZnO nanorod composite with the molar ratio of Ag₃PO₄:ZnO = 1:40 exhibited the highest photodegradation efficiency of RhB (93%), which was 1.5 times of pure ZnO nanorods.     

BiOCl and TiO2 deposited on exfoliated ZnCr-LDH to enhance visible-light photocatalytic decolorization of Rhodamine B

A series of novel TiO₂-BiOCl-ZnCr-Ex composites for use as photocatalysts were synthesized via a facile solvothermal process using an exfoliated ZnCr-LDH (ZnCr-Ex) and depositing BiOCl and TiO₂ sequentially on the surface of ZnCr-Ex. The composites were characterized by XRD, TEM, SEM-EDS and UV–vis diffuse reflectance spectroscopy. In these composites, the BiOCl nanosheets were deposited first on the surfaces of ZnCr-Ex and then the TiO₂ nanoparticles were dispersed on the surface of BiOCl-ZnCr-Ex material as were seen from SEM and TEM analyses. The photocatalytic degradation of Rhodamine B (RhB) indicated that the TiO₂-BiOCl-ZnCr-Ex composite showed much higher visible-light photocatalytic activity for degradation of RhB than TiO₂ alone, BiOCl alone or the BiOCl-ZnCr-Ex by itself. The possible mechanisms of photocatalytic activity were discussed. Moreover, the present composite photocatalysts exhibited satisfactory re-usability for at least three cycles. Because of the facile synthesis process, higher photocatalytic activity under visible light irradiation and satisfactory re-usability of these composites, they can be touted as potential catalysts for degradation of organic pollutants in wastewater treatment.     

Photocatalytic degradation of Basic Blue 41 dye under visible light over SrTiO3/Ag3PO4 hetero-nanostructures

In an attempt to develop nanostructured photocatalysts with high performance, SrTiO₃/Ag₃PO₄ hetero-nanostructures were successfully fabricated. The formed binary heterojunctions were composed of SrTiO₃ nanotubes prepared using liquid-phase deposition, and Ag₃PO₄ nanoparticles prepared using a sol–gel method. Synthesis details, including morphology, structure, and optical properties of the prepared photocatalysts, were characterized and comparatively discussed. The results showed that at an optimal ratio of SrTiO₃ to Ag₃PO₄ (20–80), the photocatalytic degradation of Basic Blue 41 under 80-min visible light irradiation is the maximum amount of 99%, which is about 4.4 and 1.5 times higher than that of pristine SrTiO₃ nanorods and Ag₃PO₄ nanoparticles, respectively. It can be due to the synergistic effect of two materials that provide high light absorption and charge carriers’ separation. Finally, a detailed possible mechanism for enhancing the photocatalytic activity of the SrTiO₃/Ag₃PO₄ hetero-nanostructures was proposed.     

Preparation and characterization of spindle-shaped nanoporous anatase TiO<Subscript>2</Subscript>–Ag<Subscript>3</Subscript>PO<Subscript>4</Subscript> heterostructure with enhanced visible light driven photocatalytic performance

A novel spindle-shaped nanoporous anatase TiO₂–Ag₃PO₄ heterostructure with high photocatalytic activity was successfully prepared by a simple method. The Ag₃PO₄ nanoparticles with a diameter of 20–50 nm were deposited on the surface of the spindle-shaped TiO₂. The effect of Ag₃PO₄ nanoparticles amounts on the photocatalytic activity was investigated. The results showed that the TiO₂–Ag₃PO₄ composite with the mass ratio of TiO₂:Ag₃PO₄ = 1:2 displayed the highest photodegradation efficiency of methylene blue (MB) and Bisphenol A (BPA), which was more highly than that of Ag₃PO₄ nanoparticles and also indicated a high stability of photocatalytic degradation. The improved activity of the TiO₂–Ag₃PO₄ composite could be attributed to the efficient separation of the photogenerated electron–hole pairs.     

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.     

TiO<Subscript>2</Subscript> porous ceramic/Ag–AgCl composite for enhanced photocatalytic degradation of dyes under visible light irradiation

TiO₂ porous ceramic/Ag–AgCl composite was prepared by incorporating AgCl nanoparticles within the bulk of TiO₂ porous ceramic followed by reducing Ag⁺ in the AgCl particles to Ag⁰ species under visible light irradiation. The porous TiO₂ ceramic was physically robust and chemically durable, and the porous structure facilitated the implantation of AgCl NPs. Compared with the bare TiO₂ ceramic, TiO₂ porous ceramic/Ag–AgCl composite exhibited higher photocatalytic performance for the degradation of MO and RhB under visible light irradiation. The reaction rate constants k of MO and RhB degradation over TiO₂ porous ceramic/Ag–AgCl composite was respectively 6.25 times and 3.62 times higher than those recorded over the bare TiO₂ porous ceramic. The photocatalytic activity showed virtually no decline after four times cyclic experiments under visible light irradiation. Scanning electron microscopy, energy dispersive X-ray analysis, X-ray diffraction, UV–Vis diffuse reflectance spectroscopy, photoluminescence spectra and X-ray photoelectron spectroscopy were used to characterize the TiO₂ porous ceramic/Ag–AgCl composite.     

One step synthesis of Ag/Ag3PO4/BiPO4 double-heterostructured nanocomposites with enhanced visible-light photocatalytic activity and stability

Heterogeneous Ag/Ag₃PO₄/BiPO₄ photocatalyst was synthesized by a one-step low temperature chemical bath method and exhibited better photocatalytic activity and better stability than those of individual Ag₃PO₄ or BiPO₄ nanoparticles for photodegradation of organic compounds (Rhodamine B) in the absence of electron accepters under visible light (λ>420 nm). The enhanced photocatalytic performance is mainly ascribed to the strong visible-light absorption originating from high efficient separations of photogenerated electron–hole pairs through Ag₃PO₄/BiPO₄ and Ag/Ag₃PO₄ heterostructures.     

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.     

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.     

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.     

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.