High Visible Light Photocatalytic Activity Research Articles

Ternary heterostructured Ag–BiVO4/InVO4 composites: Synthesis and enhanced visible-light-driven photocatalytic activity

A novel ternary heterostructured Ag–BiVO4/InVO4 composite with high visible light photocatalytic activity was synthesized through a low-temperature solution-phase route. Ag nanoparticles were photodeposited on the surface of leaf-like BiVO4/InVO4 heterojunction not only to increase visible-light absorption via the surface plasmon resonance, but also serve as good electron acceptor for facilitating quick photoexcited electron transfer. The interface between BiVO4 and InVO4 facilitates the migration of photoinduced electrons from InVO4 to BiVO4, which is also conductive to retard the recombination of electron–holes. Thus, the ternary heterostructured Ag–BiVO4/InVO4 composite photocatalysts showed significant photocatalytic activities, higher than the sum of BiVO4, the sum of InVO4, and BiVO4/InVO4 sample. It indicated that the heterostructured combination of Ag, BiVO4 and InVO4 provides synergistic photocatalytic activity through an efficient electron transfer process. The radical scavengers trapping experiments revealed superoxide radical (O2-) and hydroxyl radical (OH) are the main active species responsible for the degradation of 4-CP.

Facile preparation of anatase–brookite–rutile mixed-phase N-doped TiO2 with high visible-light photocatalytic activity

Solvent-based ambient condition sol process with N,N-dimethyl formamide (DMF) as the solvent, is a post-processing method utilized to modify mixed-phase titania nanoparticles using polyethylene glycol (PEG) as a structure directing agent prepared by self-assembly process. Photocatalytic activity, evaluated by the photocatalytic degradation of methylene blue (MB) under visible-light irradiation, demonstrated that all the samples were more active than Degussa P25. The high photocatalytic activity was explained by the presence of a ternary mixture of anatase, brookite, and rutile and the electron-deficient nitrogen atoms in O–Ti–N nitrides that could inhibit the recombination of electron–hole pairs by capturing the photoinduced electrons. From the experimental results, it was observed that the high efficiency seems to depend on the ternary (anatase, brookite, and rutile) phase effect, the chemical states of the Ti, O, and N species on the surface, the atomic content of nitrogen and BET surface area. The activity of the N-doped TiO2 first increased and then decreased with the increase of the N-content.

Facile synthesis organic–inorganic heterojunctions of HSbO3/g-C3N4 as efficient visible-light-driven photocatalyst for organic degradation

Novel HSbO3/graphitic carbon nitride (HSbO3/g-C3N4) heterojunction photocatalysts were synthesized via a simple method. The prepared HSbO3/g-C3N4 samples were characterized by X-ray powder diffraction (XRD), transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM), ultraviolet–visible diffuse reflection spectroscopy (DRS) and photoluminescence spectroscopy (PL). The photocatalytic activity of as-synthesized samples was evaluated by degrading Rhodamine B (RhB) in aqueous solution under visible-light irradiation. All the HSbO3/g-C3N4 heterojunction photocatalysts showed much higher visible-light photocatalytic activity than those of pure g-C3N4, HSbO3 for the degradation of RhB. The enhanced photocatalytic activity is mainly ascribed to the enhancement of electron–hole separations at the interface of the two semiconductors. This study offers a new class of highly efficient and promising heterojunction photocatalysts.

In-situ synthesis of plasmonic Ag/Ag3PO4 tetrahedron with exposed {111} facets for high visible-light photocatalytic activity and stability

Visible-light-driven tetrahedral Ag/Ag3PO4 photocatalyst with exposed {111} facets was successfully fabricated by a facile microwave-assisted chemical reduction method. Ag nanoparticles were in-situ synthesized on the {111} planes of Ag3PO4 with the assistance of pyridine and polyvinylpyrrolidone (PVP). Ag decorated Ag3PO4 exhibits excellent visible-light absorption and low recombination rate of charge carriers. The photocatalytic performance of the Ag/Ag3PO4 composites were evaluated by degradation of Rhodamine B (RhB) under simulated sunlight irradiation (λ>410nm). The investigations show that the active {111} planes of tetrahedral Ag3PO4 are conducive to enhancement of visible-light photocatalytic activity. Besides, Ag/Ag3PO4-0.05 composite exhibit the highest photocatalytic activity, the deposition of Ag nanoparticles on the {111} planes of Ag3PO4 can effectively improve the photocatalytiy activity and stability of Ag3PO4 due to the Schottky junction and localized surface plasmon resonance (LSPR) effect of Ag nanoparticles. The photocatalytic mechanism of the Ag/Ag3PO4 composite was also proposed.

Controlled synthesis of graphitic carbon nitride/beta bismuth oxide composite and its high visible-light photocatalytic activity

g-C3N4/β-Bi2O3 composites with high visible-light-driven photocatalytic activity were prepared through calcination of g-C3N4/Bi2O2CO3 of different proportions. They were characterized by powder X-ray diffraction (XRD), Fourier Translation infrared spectroscopy (FT-IR), field emission scanning electron microscopy (FESEM), transmission electron microscopy TEM (high resolution transmission electron microscopy HRTEM), UV–vis diffuse reflectance spectra (UV–vis DRS) and photoluminescence spectra (PL) techniques. It was observed that the phase structure of Bi2O3 is subject to the amount of g-C3N4 in the g-C3N4/Bi2O2CO3 precursor. Based on the results of light absorption and photocurrent measurement as well as the energy levels of β-Bi2O3 and g-C3N4, we propose a mechanism for the degradation of organic compounds over this class of catalysts.

A fluorine free method to synthesize nitrogen and lanthanum co-doped TiO2 nanocrystals with exposed {0 0 1} facets for enhancing visible-light photocatalytic activity

This study introduces a simple and fluorine free route to synthesize nitrogen and lanthanum co-doped TiO2 nanocrystals with exposed {001} facets through one-step hydrothermal method. The microstructure, chemical composition, and photocatalytic property of the co-doped TiO2 nanosheets were analyzed using XRD, FESEM, TEM, XPS and UV–vis. The experimental results indicated that N had been successfully doped into TiO2 lattice, while La was likely to form a binary nanocomposite with TiO2. The co-doped TiO2 nanosheets showed an additional visible light absorption band starting from 400nm, which could improve the visible light photocatalytic activity of the sample. As the shape-controlling agent, DEA plays a crucial role in the formation of {001} facets. N and La co-doping could produce a synergistic effect. N doping can narrow the band gap of anatase TiO2 and increase the utilization efficiency of visible light, while La doping can enhance the separation efficiency of photo-induced electrons and holes. N and La co-doped TiO2 nanosheets exhibited higher visible light photocatalytic activity compared with P25, N doped TiO2 nanosheets and N, La co-doped TiO2 nanoparticles with the same doping concentration. In addition, N and La co-doped TiO2 nanosheets showed well recycling performance.

SnS2 nanosheet-based microstructures with high adsorption capabilities and visible light photocatalytic activities

High adsorption capabilities and visible light photocatalytic activities of SnS2 nanosheet-based microstructures are achieved.

Electrospun nitrogen and carbon co-doped porous TiO2 nanofibers with high visible light photocatalytic activity

Synergistic effects were generated over N and C co-doped porous TiO2 nanofibers prepared by electrospinning and calcining technologies.

An organic-inorganic hybrid photocatalyst based on sandwich-type tetra-Co-substituted phosphotungstates with high visible light photocatalytic activity.

A novel 3D organic-inorganic hybrid framework constructed from tetra-Co(II)-substituted sandwich-type phosphotungstates with a rare 8-connected bcu topology is reported, which exhibited highly efficient photocatalysis activity under visible light and could be used for 5 cycles without any obvious decrease in activity.

Oxygen deficient ZnO 1-x nanosheets with high visible light photocatalytic activity.

Zinc oxide is one of the most important wide-band-gap (3.2 eV) materials with versatile properties, however, it can not be excited by visible light. In this work, we have developed an exquisite and simple way to prepare oxygen-deficient ZnO 1-x nanosheets with a gray-colored appearance and excellent visible light photocatalytic activity. Detailed analysis based on UV-Vis absorption spectra, X-band electron paramagnetic resonance (EPR) spectra, and photoluminescence (PL) spectra confirms the existence of oxygen vacancies in ZnO 1-x. The incorporation of oxygen defects could effectively extend the light absorption of ZnO 1-x into the visible-light region due to the fact that the energy of the localized state is located in the forbidden gap. Thus, our obtained ZnO 1-x shows a higher photodegradation of methyl orange (MO) compared to defect-free ZnO under visible light illumination. Additionally, the high content of ˙OH radicals with a strong photo-oxidation capability over the ZnO 1-x nanosheets significantly contributes to the improvement in the photocatalytic performance. Our oxygen deficient ZnO 1-x sample shows a very high photocatalytic activity for the degradation of MO even after 5 cycles without any obvious decline. The results demonstrate that defect engineering is a powerful tool to enhance the optoelectronic and photocatalytic performances of nanomaterials.

Facile preparation of C-modified TiO2 supported on MCF for high visible-light-driven photocatalysis

This study developed a facile approach for preparing C-modified TiO2/MCF with high visible light photocatalytic activity by a hydrothermal and thermal treatment method.

One-step hydrothermal synthesis of cobalt and potassium codoped CdSe quantum dots with high visible light photocatalytic activity

The effect of metal ion doping on the electronic structure and optical properties of CdSe quantum dots has been investigated by various characterization techniques and experiments.

Fabrication of novel perovskite-type Sr2Ta(Fe1−xGax)O6nanoparticles with high visible-light photocatalytic activity

Novel Sr2Ta(Fe1−xGax)O6perovskite photocatalysts with the excellent photocatalytic activity were successfully synthesized by a simple one-step sol–gel method.

Bioprocess-inspired synthesis of hierarchically porous nitrogen-doped TiO2with high visible-light photocatalytic activity

A bioprocess-inspired approach is designed to synthesize hierarchically porous N-TiO2with a high photocatalytic activity by using natural proteins as templates.

Enhanced visible light photocatalytic hydrogen production activity of CuS/ZnS nanoflower spheres

The ZnS nanoflower architectures reach a high visible light photocatalytic hydrogen production activity with the deposition of a small portion of CuS nanoparticles.

Porous P-doped graphitic carbon nitride nanosheets for synergistically enhanced visible-light photocatalytic H2production

Porous P-doped g-C3N4nanosheets prepared by combining P doping and thermal exfoliation exhibit a high visible-light photocatalytic H2-production activity of 1596 μmol h−1g−1and a quantum efficiency of 3.56% at 420 nm.

Carbon-doped titania nanoplates with exposed {001} facets: facile synthesis, characterization and visible-light photocatalytic performance

C-doped TiO2 nanoplates (CTNP) with exposed {001} facets were synthesized for the first time. The obtained CTNP presented high visible-light photocatalytic activity. A reasonable mechanism of photocatalysis on CTNP under visible light was proposed.

Large-scale synthesis of self-assembled ultralong cannonite nanobelt film as a visible-light photocatalyst

Self-assembled macroscopic cannonite nanobelts could be transferred on substrates as thin films in a large scale and exhibit high visible-light photocatalytic activity, which would be a promising candidate for high-efficiency photocatalysts.

Cu-Supported TiO<sub>2 </sub>with High Visible-Light Photocatalytic Activity Prepared Using Cupric Acetate

Cu-Supported TiO<sub>2 </sub>with High Visible-Light Photocatalytic Activity Prepared Using Cupric Acetate

Synthesis of Ag3PO4–Bi2O2CO3 composites with high visible-light photocatalytic activity

Ag3PO4–Bi2O2CO3 composites were prepared by a combination of hydrothermal technique and precipitation method for the first time. Ag3PO4 nanoparticles with ca. 200nm in size were attached to the surface of Bi2O2CO3 microspheres in diameter of 1–2μm, which had higher photocatalytic activity than Bi2O2CO3 microspheres toward degradation of Rhodamine B (RhB) in water under visible light irradiation. The Ag3PO4–Bi2O2CO3 composite with the molar ratio of Ag3PO4:Bi2O2CO3=1:1 exhibited the highest photodegradation efficiency of RhB (97% in 30min), which was about 2.2 times of pure Bi2O2CO3 microspheres. The enhanced photoactivity could be ascribed to more light harvest and more effective separation of photo-generated electron–hole pairs.