Photocatalyst Bi Research Articles

SINTESIS TiO2 TERDOPING Bi3+ DAN UJI AKTIVITAS FOTOKATALISIS ANTIBAKTERI E.coli DENGAN BANTUAN SINAR TAMPAK (SYNTHESIS OF Bi3+ DOPED TiO2 AND PHOTOCATALYSIS ACTIVITY TEST OF E.coli ANTIBACTERIA UNDER VISIBLE IRRADIATION)

The synthesis of Bi3+ doped TiO2 was carried out using the sol-gel method with the precursor solution of titanium tetraisopropoxide (TTiP). Bi3+ cation dopant is done to reduce the energy of the TiO2 band gap so that it can be active in the visible light region. The synthesized Bi(III) –TiO2 photocatalyst was characterized using DRS UV-Vis, FTIR, and EDX. The results of the DRS UV-Vis analysis showed that 1% Bi(III) –TiO2 photocatalyst had a bandgap energy of 2.79 eV or equivalent to a wavelength of 469.97 nm. Infrared spectra show that there is a unique absorption at the wave number 956,56 cm-1 which is the absorption of the vibration Bi-O-Ti group. Photocatalyst Bi(III) -TiO2 was then tested for antibacterial activity against E. coli in polluted water. The activity test was carried out using the turbidimetric method by UV-vis spectrophotometry. The results of the activity test for 120 minutes with the help of visible light showed that the photocatalyst Bi(III) –TiO21% had the best antibacterial activity. The decrease in the number of E. coli in the water reached 48.54%.

A TiO2NW “bridged” composite photocatalyst Bi12O17Cl2–TiO2NW / Fe2TiO5 / Fe2O3 for water treatment driven by visible light

The high recombination rate of Bi 12 O 17 Cl 2 carrier and the limitation of visible light absorption of TiO 2 seriously hinder the application of photocatalytic water treatment pollution. In this work, we grow Fe 2 O 3 and Fe 2 TiO 5 uniformly in situ on TiO 2 –Bi 12 O 17 Cl 2 (hydrothermally constructed) heterojunction nanomaterials by the ion exchange method. Thus constructing a kind of three-heterojunction composite photocatalyst. XRD, SEM, XPS and other characterization tests were performed on the product to show the sample's morphology, composition, and photoelectric properties. The prepared photocatalyst induces photoelectrons under visible light and shows excellent photodegradation mineralization properties for methylene blue. Besides, the catalyst has cycle practicability and stability. Finally, through the valence band theory and the active species capture experiment, the degradation mechanism of the heterojunction's synergistic effect and the Fenton effect is proposed. The construction of nanocomposite provides a promising photocatalytic strategy for the Fenton reaction system based on heterojunction. • Prepared new photocatalyst Bi 12 O 17 Cl 2 –TiO 2 NW/Fe 2 TiO 5 /Fe 2 O 3 by Hydrothermal method. • The degradation rate of methylene blue reached 99.0% at 60min. • The degradation rate was 25.9 times that of adding photocatalyst alone. • The degradation efficiency is 11.2 times that of adding H 2 O 2 alone. • Heterojunction and Fenton effect synergistically improve photocatalytic performance.

A novel nano-sized MoS2 decorated Bi2O3 heterojunction with enhanced photocatalytic performance for methylene blue and tetracycline degradation

In this paper, MoS 2 was used as a band-suitable semiconductor to construct the Bi 2 O 3 /MoS 2 heterostructured photocatalysts for the first time via a deposition-hydrothermal method. The XRD, SEM and HRTEM analysis indicated that the surface of Bi 2 O 3 was decorated with MoS 2 nanoparticles and Bi 2 O 3 /MoS 2 heterojunctions were formed. The performances on photocatalytic degradation of methylene blue (MB) and tetracycline (TC) were evaluated under visible light irradiation. The results demonstrated that the Bi 2 O 3 /MoS 2 heterojunctions displayed remarkably improved photocatalytic activity for both MB and TC degradation, compared to the base material (Bi 2 O 3 ). Specifically, as the molar ratio of MoS 2 was 23.81%, the obtained Bi 2 O 3 /MoS 2 -23.81 heterojunctions exhibited promising photocatalytic activities, and approximately 100% MB and 97% TC were degraded within 100 min, respectively. The superior photocatalytic activity was mainly attributed to its large surface area, high visible-light harvesting and the efficient separation of photogenerated electrons and holes caused by the unique heterojunction architecture. Notably, the Bi 2 O 3 /MoS 2 heterojunctions showed remarkable stability in recycling photocatatlytic experiments. The active species trapping and terephthalic acid (TA) fluorescence experiments indicated that the •OH was the major reactive oxidizing species for MB degradation. Furthermore, the intermediates were detected by UPLC-MS spectrometry and the possible degradation pathways for MB and TC were proposed. Finally, a possible reaction mechanism of Bi 2 O 3 /MoS 2 heterojunctions for the photodegradation MB was also proposed. This interesting interfacial architecture strategy will provide useful insights for designing and fabricating new class of binary heterojunctions with high-efficient photocatalytic activity towards practical application. A highly efficient visible-light responsive photocatalyst Bi 2 O 3 /MoS 2 heterojunctions was prepared for the organic dyes and antibiotic pollutants elimination. • Bi 2 O 3 /MoS 2 heterojunction was prepared by deposition-hydrothermal method. • Bi 2 O 3 /MoS 2 -23.81 exhibited enhanced photocatalytic activity than that of pure Bi 2 O 3 . • The electrons transfer and visible-light harvesting effects were obviously improved. • The ⋅OH was the main oxidative species of Bi 2 O 3 /MoS 2 -23.81 for the MB decomposition.

ChemInform Abstract: Direct Hydrolysis Preparation for Novel Bi‐Based Oxysalts Photocatalyst Bi6O5(OH)3 (NO3)5·3H2O with High Photocatalytic Activity.

AbstractThe title compound is prepared from aqueous Bi(NO3)3·5H2O solutions by sonication for 2 min and further magnetic stirring for 2 h at room temperature.

Layered photocatalyst Bi2O2[BO2(OH)] nanosheets with internal polar field enhanced photocatalytic activity

Layered photocatalyst Bi2O2[BO2(OH)] nanosheets efficiently separated photogenerated carriers due to the internal polar electric field, which enhances the photocatalytic activity.

Preparation of magnetic composite photocatalyst Bi2WO6/CoFe2O4by two-step hydrothermal method and itsphotocatalytic degradation of bisphenol A

Abstract Easily separable magnetic photocatalyst Bi 2 WO 6 /CoFe 2 O 4 was synthesized by a two-step hydrothermal method. Pure spinel CoFe 2 O 4 in nano-scale was prepared by a hydrothermal method, which was followed by a second hydrothermal process to coat CoFe 2 O 4 with Bi 2 WO 6 . The prepared Bi 2 WO 6 /CoFe 2 O 4 kept the magnetic property of CoFe 2 O 4 and high efficient photocatalytic activity of Bi 2 WO 6 as well. The photoactivity of Bi 2 WO 6 /CoFe 2 O 4 (mass ratio 10:1) to degrade bisphenol A (BPA) was close to that of pure Bi 2 WO 6 after 120 min of simulated solar light irradiation. After reaction, the catalyst particles could be easily harvested from the suspension by applying an external magnetic field.

Self-assembled 3D architectures of Bi2TiO4F2 as a new durable visible-light photocatalyst

A new hierarchical visible-light-driven photocatalyst Bi(2)TiO(4)F(2) was synthesized by a solvothermal method for the first time. The photocatalyst was characterized by X-ray powder diffraction (XRD), field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), N(2) adsorption-desorption (BET), UV-vis diffuse reflectance spectroscopy (DRS). Such hierarchical Bi(2)TiO(4)F(2) microspheres assembled by nanosheets were fabricated via an Ostwald ripening process in the absence of soft templates (surfactants). The as-prepared samples' bimodal pore-size distributions in the mesoporous region consisted of smaller intra-aggregated pores with peak pore diameter of ca. 4.6 nm and larger inter-aggregated pores with peak pore diameter of ca. 17.0 nm. The band gap of the obtained Bi(2)TiO(4)F(2) was estimated to be about 2.71-3.06 eV for various solvothermal treatment time. Owing to the hierarchical structure with bimodal pores, low band gaps and high crystallinity, the Bi(2)TiO(4)F(2) microspheres exhibited high photocatalytic performance and durability for the degradation of rhodamine B (RhB) under visible light (> 420 nm). It was proved that the photo-generated holes and ˙OH radicals played an essential role for the oxidation of RhB.

Synthesis and structural characterization of novel visible photocatalyst Bi–TiO2/SBA-15 and its photocatalytic performance

Bi-doped TiO2/SBA-15 (Bi–TiO2/SBA-15) was synthesized by a wet impregnation method. It was found that SBA-15 retained its ordered hexagonal mesostructure after incorporation of TiO2 and Bi. TiO2 nanoparticles and Bi species dispersed well and anchored both in the channel and the wall of SBA-15. The photocatalytic activity was evaluated on photodegradation of Rhodamine B (RhB) under visible light irradiation (λ ≥ 420 nm). Experimental results indicated that Bi–TiO2/SBA-15 exhibited higher photocatalytic activities than pure TiO2 and TiO2/SBA-15 owing to the synergetic effects of Bi species and TiO2. The degradation of RhB by these catalysts follows the pseudo-first-order kinetic model and Bi–TiO2/SBA-15 (2.0%) was found to be the best. The effect of Bi doping on the photocatalytic activity was investigated by the density functional theory (DFT) method. The calculated results indicated that Bi doping could improve the photocatalytic activity by extending the spectral response from UV to the visible region, making the Bi–TiO2/SBA-15 active under visible light irradiation.

Photocatalytic degradation of azo dye by novel Bi-based photocatalyst Bi 4TaO 8I under visible-light irradiation

In this work, a novel Bi-based oxyhalide Bi 4TaO 8I was prepared and characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and UV–vis diffuse reflectance spectroscopy. Photocatalytic activity of this material was evaluated by using methyl orange (MO) as a representative azo dye. It was found that Bi 4TaO 8I had a visible light absorption, and the band-gap energy was estimated to be 2.43 eV. This material exhibited good photocatalytic activity under both ultraviolet and visible light irradiation. The effects of initial MO concentration, aqueous pH, catalyst dosage and irradiation time on the photocatalytic activity were studied systematically. The photocatalytic degradation of MO by Bi 4TaO 8I under visible-light irradiation was found to follow the pseudo first-order reaction at the low initial concentrations of MO. Reuse of the catalyst was also examined, and the degradation efficiency of MO was still as high as 60% after 3 cycles of 28 h visible-light irradiation. Furthermore, it was found that the degradation of MO was also effective under solar irradiation. Five main degradation products were observed by HPLC/MS and their chemical structures were suggested. In order to exclude the photosensitization effect, the photocatalytic degradation efficiency of pentachlorophenol (PCP) by Bi 4TaO 8I was also determined under visible light irradiation. It is expected that Bi 4TaO 8I would have potential application in the degradation of azo dye wastewaters under solar irradiation.

Characterization of photocatalyst Bi3.84W0.16O6.24 and its photodegradation on bisphenol A under simulated solar light irradiation

Bismuth tungsten oxide Bi3.84W0.16O6.24 was prepared by hydrothermal process under pH 12. Both the hydrothermal reaction temperature and time affected the crystallinity and morphology of the prepared catalysts, which in turn affected their degradation efficiency. Although all the prepared catalysts showed adsorption in the visible region around 450nm, the catalyst synthesized at 140°C for 20h displayed the highest photocatalytic degradation capacity to bisphenol A (BPA) under simulated solar light irradiation due to the combination of its good crystallinity and perfect disk morphology. In the photodegradation system of BPA and Bi3.84W0.16O6.24, no OH was detected by electron spin resonance analysis, suggesting that direct hole is predominant in the degradation of BPA by Bi3.84W0.16O6.24. It displayed high photocatalytic degradation and mineralization capacities to BPA as compared with P25 TiO2 under simulated solar light irradiation. The analytical results of both LC–MS and GC–MS demonstrated that no hydroxylated intermediates were formed. A simple and direct photodegradation pathway of BPA by Bi3.84W0.16O6.24 was proposed by the analysis of intermediates.

Methyl orange degradation over a novel Bi-based photocatalyst Bi 3SbO 7: Correlation of crystal structure to photocatalytic activity

Bi 3SbO 7 was synthesized by a solid state reaction method and the as-synthesized powder was characterized by X-ray diffraction (XRD) and UV–vis diffuse reflectance spectrum. The photocatalytic activity of Bi 3SbO 7 was evaluated by means of the degradation of methyl orange; the effects of photocatalyst concentration, pH and wavelength of irradiation upon photocatalytic performance were investigated. The photocatalytic character of Bi 3SbO 7 was discussed in terms of band structure and crystal structure. The results obtained reveal that Bi 3SbO 7 has an intrinsic optical band gap of 2.71 eV and can photocatalytically respond to light upto ∼600 nm. Generally, Bi 3SbO 7 shows better photocatalytic activities than BiVO 4 under both UV and visible light because of the lower packing factor and correspondingly higher structural openness of Bi 3SbO 7.

Photocatalytic properties of bismuth titanate Bi 12TiO 20 prepared by co-precipitation processing

A visible-light-active photocatalyst Bi 12TiO 20 with sillenite structure was prepared by a simple co-precipitation method. The spectrum of UV–vis absorption indicated that the absorption edge of the Bi 12TiO 20 was at 450 nm, corresponding to the band gap energy of 2.75 eV. The prepared Bi 12TiO 20 showed high photocatalytic activity for the degradation of phenol in water either under UV (300 nm < λ < 400 nm) or visible light ( λ > 400 nm) irradiation. The photodegradation experiments of phenol indicated that the prepared photocatalyst calcined at 550 °C had the best photocatalytic activity.

Visible-light-driven photocatalyst of Bi 2WO 6 nanoparticles prepared via amorphous complex precursor and photocatalytic properties

The visible-light-driven photocatalyst Bi 2WO 6 nanoparticles have been prepared by calcining amorphous complex precursor at a relatively low temperature of above 450 oC. The effects of calcination temperature and time on the structures and properties of Bi 2WO 6 nanoparticles have been investigated in detail. The photocatalytic activity of the Bi 2WO 6 powders were evaluated by degradation of RhB molecules in water under visible light irradiation ( λ>400 nm). The results showed that the particle size and grain size of Bi 2WO 6 increased with the calcination temperature and time. The photocatalytic activity of the best sample was about 8.8 times higher than that of the sample prepared by traditional solid state reaction and the photo-degradations was a zero-order reaction. The best route to enhance the photocatalytic activity of Bi 2WO 6 was to prepare the sample at a lower temperature for a longer time, due to the samples with better crystallization and smaller particle size.

Synthesis, Structure and Photocatalytic Property of a New Hydrogen Evolving Photocatalyst Bi&lt;sub&gt;2&lt;/sub&gt;InTaO&lt;sub&gt;7&lt;/sub&gt;

Synthesis, Structure and Photocatalytic Property of a New Hydrogen Evolving Photocatalyst Bi&lt;sub&gt;2&lt;/sub&gt;InTaO&lt;sub&gt;7&lt;/sub&gt;

Optical and structural properties of solid oxide photocatalyst Bi2FeNbO7

Polycrystalline sample of Bi2FeNbO7 was synthesized by the solid-state reaction and characterized by powder x-ray diffraction and Rietveld structure refinement. The optical absorption and structural properties of Bi2FeNbO7 were investigated. It was found that the Bi2FeNbO7 compound has the pyrochlore crystal structure, cubic system with space group Fd3m, and the lattice parameter is a = 10.5233(2) Å. Ultraviolet-visible diffuse reflectance spectroscopy measurement revealed that the band gap of Bi2FeNbO7 is about 2.1(6) eV.

Optical and electrical properties of solid photocatalyst Bi2InNbO7

A polycrystalline sample of Bi2InNbO7 was synthesized by a solid-state reaction and characterized by powder x-ray diffraction and Rietveld structure refinement. The optical absorption and electrical properties of Bi2InNbO7 were investigated. It was found that the Bi2InNbO7 compound exhibited a direct gap semiconducting behavior. Conductivity measurement showed the compound had an activation energy of 2.62(5) eV. Ultraviolet–visible diffuse reflectance spectroscopy measurement revealed that the band gap of Bi2InNbO7 is about 2.7(4) eV.