Browse
Submit Data
Databases
API
Help

Dataset Information

16 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Efficient Visible-Light Photocatalysis of TiO_2-δ Nanobelts Utilizing Self-Induced Defects and Carbon Doping.

ABSTRACT: Efficient visible-light photocatalysis was realized by exploring self-induced defect states, including the abundant surface states of TiO_2-δ nanobelts synthesized through metal-organic chemical vapor deposition (MOCVD). The TiO_2-δ nanobelts exhibited two strong defect-induced absorption peaks at 2.91 and 1.92 eV, overlapping with the conduction band states so that photoexcited carriers can contribute effectively for the photocatalysis reaction. To further enhance visible-light photocatalytic activity, carbon atoms, the by-product of the MOCVD reaction, were self-doped at the judiciously determined growth conditions. The resulting visible-light photocatalysis suggests that the large surface area and consequent high concentration of the surface states of the TiO_2-δ nanobelts can be effectively utilized in a wide range of photocatalysis applications.

SUBMITTER: Seo DB

PROVIDER: S-EPMC8224642 | biostudies-literature |

REPOSITORIES: biostudies-literature

ACCESS DATA

Json Xml

Similar Datasets

Titanium dioxide visible light photocatalysis: surface association enables photocatalysis with visible light irradiation.

Project description:Titanium dioxide (TiO2) is a widely employed and inexpensive photocatalyst, but its use in organic synthesis has been limited by the short-wavelength ultraviolet irradiation typically used. We have discovered that TiO2 particles efficiently mediate photocatalytic radical cation Diels-Alder cycloadditions using a simple visible light source, enabled by the formation of a visible light absorbing complex of the substrate on the semiconductor surface.

| S-EPMC5657382 | biostudies-literature

Contaminant-Activated Visible Light Photocatalysis.

Project description:Pristine titanium dioxide (TiO2) absorbs ultraviolet light and reflects the entire visible spectrum. This optical response of TiO2 has found widespread application as white pigments in paper, paints, pharmaceuticals, foods and plastic industries; and as a UV absorber in cosmetics and photocatalysis. However, pristine TiO2 is considered to be inert under visible light for these applications. Here we show for the first time that a bacterial contaminant (Staphylococcus aureus-a MRSA surrogate) in contact with TiO2 activates its own photocatalytic degradation under visible light. The present study delineates the critical role of visible light absorption by contaminants and electronic interactions with anatase in photocatalytic degradation using two azo dyes (Mordant Orange and Procion Red) that are highly stable because of their aromaticity. An auxiliary light harvester, polyhydroxy fullerenes, was successfully used to accelerate photocatalytic degradation of contaminants. We designed a contaminant-activated, transparent, photocatalytic coating for common indoor surfaces and conducted a 12-month study that proved the efficacy of the coating in killing bacteria and holding bacterial concentrations generally below the benign threshold. Data collected in parallel with this study showed a substantial reduction in the incidence of infections.

| S-EPMC5789862 | biostudies-other

Short-Time Hydrothermal Synthesis of CuBi2O4 Nanocolumn Arrays for Efficient Visible-Light Photocatalysis.

Project description:In this article, a short-time hydrothermal method is developed to prepare CuBi2O4 nanocolumn arrays. By using Bi(NO3)3·5H2O in acetic acid and Cu(NO3)2·3H2O in ethanol as precursor solutions, tetragonal CuBi2O4 with good visible light absorption can be fabricated within 0.5 h at 120 °C. Tetragonal structured CuBi2O4 can be formed after 15 min hydrothermal treatment, however it possesses poor visible light absorption and low photocatalytic activity. Extending the hydrothermal treatment duration to 0.5 h results in a significant improvement invisible light absorption of the tetragonal CuBi2O4. The CuBi2O4 obtained through 0.5 h hydrothermal synthesis shows a band gap of 1.75 eV and exhibits the highest photocatalytic performance among the CuBi2O4 prepared with various hydrothermal time. The removal rate of methylene blue by the 0.5 h CuBi2O4 reaches 91% under visible light irradiation for 0.5 h. This study proposes a novel strategy to prepare photoactive CuBi2O4 nanocolumn arrays within 0.5 h at a moderate temperature of 120 °C. The hydrothermal method provides a facile strategy for the fast synthesis of metal-oxide-based photocatalysts at mild reaction conditions.

| S-EPMC6780588 | biostudies-literature

Visible Light Photocatalysis of 6? Heterocyclization.

Project description:Photo-mediated 6? cyclization is a valuable method for the formation of fused heterocyclic systems. Here we demonstrate that irradiation of cyclic 2-aryloxyketones with blue LED light in the presence of an IrIII complex leads to efficient and high yielding arylation across a panoply of substrates by energy transfer. 2-Arylthioketones and 2-arylaminoketones also cyclize effectively under these conditions. Quantum calculation demonstrates that the reaction proceeds via conrotatory ring closure in the triplet excited state. Subsequent suprafacial 1,4-hydrogen shift and epimerization leads to the observed cis-fused products.

| S-EPMC5575533 | biostudies-other

Towards visible light hydrogen generation: quantum dot-sensitization via efficient light harvesting of hybrid-TiO2.

Project description:We report pronounced enhancement of photoelectrochemical hydrogen generation of a quantum dot-sensitized hybrid-TiO2 (QD/H-TiO2) electrode that is composed of a mesoporous TiO2 layer sandwiched by a double sided energy harvesting layer consisting of a surface-textured TiO2 inverse opals layer on the bottom and a patterned mesoporous TiO2 layer on the top. CdSe/H-TiO2 exhibits a maximum photocurrent density of ~16.2?mA/cm(2), which is 35% higher than that of the optimized control sample (CdSe/P25), achieved by matching of the bandgap of quantum dot-sensitization with the wavelength where light harvesting of H-TiO2 is observed. Furthermore, CdSe/H-TiO2 under filtered exposure conditions recorded current density of ~14.2?mA/cm(2), the greatest value in the visible range. The excellent performance of the quantum dot-sensitized H-TiO2 suggests that alteration of the photoelectrodes to suitable nanostructures with excellent light absorption may offer optimal strategies for attaining maximum efficiency in a variety of photoconversion systems.

| S-EPMC3839030 | biostudies-literature

Solar synthesis: prospects in visible light photocatalysis.

Project description:Chemists have long aspired to synthesize molecules the way that plants do-using sunlight to facilitate the construction of complex molecular architectures. Nevertheless, the use of visible light in photochemical synthesis is fundamentally challenging because organic molecules tend not to interact with the wavelengths of visible light that are most strongly emitted in the solar spectrum. Recent research has begun to leverage the ability of visible light-absorbing transition metal complexes to catalyze a broad range of synthetically valuable reactions. In this review, we highlight how an understanding of the mechanisms of photocatalytic activation available to these transition metal complexes, and of the general reactivity patterns of the intermediates accessible via visible light photocatalysis, has accelerated the development of this diverse suite of reactions.

| S-EPMC4547527 | biostudies-literature

Facile Synthesis of Defective TiO2-x Nanocrystals with High Surface Area and Tailoring Bandgap for Visible-light Photocatalysis.

Project description:A facile hydrothermal approach has been developed to prepare defective TiO2-x nanocrystals using Ti(III)-salt as a precursor and L-ascorbic acid as reductant and structure direction agent. The prepared TiO2-x nanocrystals are composed of a highly crystallized TiO2 core and a disordered TiO2-x outer layer, possessing high surface area, controlled oxygen vacancy concentration and tunable bandgap via simply adjusting the amount of added L-ascorbic acid. The defective TiO2-x shows high photocatalytic efficiency in methylene blue and phenol degradation as well as in hydrogen evolution under visible light, underlining the significance of the present strategy for structural and bandgap manipulation in TiO2-based photocatalysis.

| S-EPMC4626796 | biostudies-literature

Highly Visible Light Responsive, Narrow Band gap TiO2 Nanoparticles Modified by Elemental Red Phosphorus for Photocatalysis and Photoelectrochemical Applications.

Project description:This paper reports that the introduction of elemental red phosphorus (RP) into TiO2 can shift the light absorption ability from the UV to the visible region, and confirmed that the optimal RP loading and milling time can effectively improve the visible light driven-photocatalytic activity of TiO2. The resulting RP-TiO2 nanohybrids were characterized systematically by a range of techniques and the photocatalytic ability of the RP-TiO2 photocatalysts was assessed further by the photodegradation of a model Rhodamine B pollutant under visible light irradiation. The results suggest that the RP-TiO2 has superior photodegradation ability for model contaminant decomposition compared to other well-known photocatalysts, such as TiO2 and other reference materials. Furthermore, as a photoelectrode, electrochemical impedance spectroscopy, differential pulse voltammetry, and linear scan voltammetry were also performed in the dark and under visible light irradiation. These photoelectrochemical performances of RP-TiO2 under visible light irradiation revealed more efficient photoexcited electron-hole separation and rapid charge transfer than under the dark condition, and thus improved photocatalytic activity. These findings show that the use of earth abundant and inexpensive red phosphorus instead of expensive plasmonic metals for inducing visible light responsive characteristics in TiO2 is an effective strategy for the efficient energy conversion of visible light.

| S-EPMC4857111 | biostudies-literature

[2+2] cycloadditions by oxidative visible light photocatalysis.

Project description:Photochemical reactions are remarkable for their ability to easily assemble cyclobutanes and other strained ring systems that are difficult to construct using other conventional synthetic methods. We have previously shown that Ru(bpy)(3)(2+) is an efficient photocatalyst that promotes the [2+2] cycloadditions of electron-deficient olefins with visible light. Here, we show that Ru(bpy)(3)(2+) is also an effective photocatalyst for the [2+2] cycloaddition of electron-rich olefins. This transformation is enabled by the versatile photoelectrochemical properties of Ru(bpy)(3)(2+), which enables either one-electron reduction or one-electron oxidation of interesting organic substrates under appropriate conditions.

| S-EPMC2892825 | biostudies-literature

TiO2 Fibers Supported ?-FeOOH Nanostructures as Efficient Visible Light Photocatalyst and Room Temperature Sensor.

Project description:Hierarchical heterostructures of beta-iron oxyhydroxide (?-FeOOH) nanostructures on electrospun TiO2 nanofibers were synthesized by a facile hydrothermal method. This synthesis method proves to be versatile to tailoring of ?-FeOOH structural design that cuts across zero-dimensional particles (TF-P), one-dimensional needles (TF-N) to two-dimensional flakes (TF-F). In addition, synthesizing such oxyhyroxide nanostructures presents the advantage of exhibiting similar functional performances to its oxides counterpart however, without the need to undergo any annealing step which leads to undesirable structural collapse or sintering. The as-prepared hierarchical heterostructures possess high surface area for dye adsorptivity, efficient charge separation and visible photocatalytic activity. Also, for the first time, hydrogen gas sensing has been demonstrated on ?-FeOOH nanostructures at room temperature. The reported hierarchical heterostructures of ?-FeOOH on TiO2 nanofibers afford multiple functions of photocatalysis and sensing which are highly promising for environment monitoring and clean up applications.

| S-EPMC4450542 | biostudies-literature