Square-like B doped TiO2 nanocrystals were first synthesized by a mild solvothermal method with H3BO4 and titanium isopropoxide as the precursors, and isopropyl alcohol as reaction medium. Then, Ag nanoparticles were deposited on TiO2-B nanosquares by photo-deposition. The as-synthesized products have been investigated by photocatalytic reaction test and characterized by powder X-ray diffraction (XRD), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), and UV–vis diffuse reflectance spectra (DRS). The results showed that boron was successfully doped into TiO2 nanosquares under solvothermal condition. The obtained Ag/TiO2-B composite showed high efficiency in degradation of acid orange II under visible light irradiation. The high photocatalytic performance could be attributed to the synergistic effect of B doping and the plasmon photocatalysis role of the deposited silver nanoparticles over TiO2. 相似文献
In this study, CdS combined graphene/TiO2 (CdS-graphene/TiO2) composites were prepared by a sol–gel method to improve on the photocatalytic performance of TiO2. These composites were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray analysis (EDX) and transmission electron microscopy (TEM). The photocatalytic activities were examined by the degradation of methylene blue (MB) under visible light irradiation. The photodegradation rate of MB under visible light irradiation reached 90·1% during 150 min. The kinetics of MB degradation were plotted alongside the values calculated from the Langmuir–Hinshelwood equation. 0·1 CGT sample showed the best photocatalytic activity, which was attributed to a cooperative reaction between the increase of photo-absorption effect by graphene and photocatalytic effect by CdS. 相似文献
Utilizing the amphiphilic triblock copolymer Pluronic P123 as the surfactant, and Ti(O(n)Bu)(4) and ZrOCl(2)·8H(2)O as the inorganic sources, a series of multi-modal mesoporous TiO(2)-ZrO(2) composites have been successfully synthesized through a one-step method. The resultant materials were characterized in detail by x-ray diffraction, atomic force microscopy, high resolution scanning electron microscopy, transmission electron microscopy, N(2) adsorption and water contact angle measurements. The effect of calcination temperatures on the physical parameters, hydrophilicity and photocatalytic activity of the obtained mesoporous TiO(2)-ZrO(2) composites was also investigated in this paper. 相似文献
Journal of Materials Science - Due to the development of industries, environmental problems attract much attention, and photocatalyst degradation of dye materials has been considered an effective... 相似文献
In this study, we have successfully deposited N-doped SiO2/TiO2 thin films on ceramic tile substrates by sol–gel method for auto cleaning purpose. After dip coating and annealing process the film was transparent, smooth and had a strong adhesion on the ceramic tile surface. The synthesised catalysts were then characterised by using several analytical techniques such as X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), atomic force microscope (AFM) and UV-vis absorption spectroscopy (UV-vis). The analytical results revealed that the optical response of the synthesised N-doped SiO2/TiO2 thin films was shifted from the ultraviolet to the visible light region. The nitrogen substituted some of the lattice oxygen atoms. The surface area of co-doped catalyst increased, and its photocatalytic efficiency was enhanced. The photocatalytic tests indicated that nitrogen co-doped SiO2/TiO2 thin films demonstrated higher than of the SiO2/TiO2 activity in decolouring of methylene blue under visible light. The enhanced photocatalytic activity was attributed to an increasing of the surface area and a forming of more hydroxyl groups in the doped catalyst. 相似文献
To improve visible-light-driven photocatalytic activity of TiO2, the octahedral Bi2Ti2O7 nanoparticles have been successfully supported on TiO2 nanotubes (Bi2Ti2O7/TiO2) for the first time by a simple hydrothermal method. The structure and electro-optical property of the Bi2Ti2O7/TiO2 were characterized in detail. The obtained Bi2Ti2O7/TiO2 exhibited a markedly enhanced photocatalytic activity and good stability for degradation of organic pollutants under visible light. The study presents a new way to synthesize Bi2Ti2O7/TiO2 using TiO2 nanotubes as both supporter and reactant. 相似文献
Journal of Materials Science: Materials in Electronics - The magnetic recoverable ZnO/ZnFe2O4/diatomite (ZZFDT) composite was synthesized by hydrothermal-precipitation method. The structure,... 相似文献
Magnetic TiO2/SiO2/CoFe2O4 nanoparticles (TiO2/SCFs) were prepared by a sol-gel process in a reverse microemulsion combined with solvent-thermal technique. TiO2/SCFs were characterized by Fourier transform infrared spectrometry, thermogravimetric analysis-differential scanning calorimetry, X-ray diffraction, Raman spectrometry, TEM, BET specific surface area measurement, and magnetic analysis. Structure analyses indicated that TiO2/SCFs presented a core-shell structure with TiO2 uniformly coating on SiO2/CoFe2O4 nanomagnets (SCFs) and typical ferromagnetic hysteresis. TiO2/SCFs showed larger specific surface area and better photocatalytic activities than TiO2 and TiO2/CoFe2O4 photocatalysts prepared by the same method. The doping interaction between TiO2 and CoFe2O4 reduced thanks to the inert SiO2 mesosphere. 相似文献
We have studied the influence of Nb content (0.35–60 wt %) and heat treatment on the phase composition, texture, and photocatalytic activity (PCA) of composites based on titanium(IV) and niobium(V) oxides and obtained materials that possess PCA under illumination at λ ≥ 900 nm. 相似文献
Carbon-loaded BiVO4 composite photocatalysts were prepared using an impregnation method, and their ability to photocatalytically degrade Rhodamine B dye solution under visible light irradiation was investigated. The prepared composite photocatalysts were characterized by X-ray diffraction (XRD), field-emission electron microscopy (FESEM), high-resolution transmission electron microscopy (HRTEM), Brunauer–Emmett–Teller (BET) surface area measurements, and UV–vis diffuse reflectance spectra. We found that the carbon was well-dispersed on the surface of BiVO4. The photocatalytic activity of the composite photocatalysts for the degradation of Rhodamine B (RhB) in aqueous solution under visible light irradiation (>420 nm) was higher than that of pure BiVO4. Moreover, the degradation efficiency increased as the carbon content increased up to 3 wt%. The mechanism of enhanced photocatalytic activity is discussed with reference to surface area, optical absorption properties, and charge separation. 相似文献
A novel photocatalysis material, F-Si-comodified TiO(2) (FST) powder, was synthesized by ultrasound-assisted hydrolysis. The prepared material was characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and UV-visible absorption spectroscopy, respectively. XRD analysis indicated that the phase of FST was pure anatase and Si atoms suppressed the growth of titania crystalline, XPS spectra showed that FST was composed of Ti, O, Si and F element, the band gap energy of FST calculated according to the spectrum of UV-vis absorption was 3.26 eV. The electron spin resonance (ESR) spin-trapping technique using 5,5-dimethyl-1-pyrroline-N-oxide (DMPO) as the spin-trap reagent has been applied to detect free radical intermediates generated from FST. ESR results showed the concentration of the active species (OH) on FST is higher than those on F-doping TiO(2) (FT), Si-modifying TiO(2) (ST) and P25 titania. The degradation of pentachlorophenol (PCP) in the microwave-assisted photocatalysis (MAPC) process was faster than other processes including microwave-assisted direct photolysis (MADP), microwave process alone (MP) and dark process (DP). The photocatalytic activity of FST is much higher than that of ST, FT and P25 titania. It may be attributed to its strong capacity of absorption to the UV-vis irradiation and more hydroxyl radical on surface of FST. In MPAC process, 40 mg L(-1) PCP was completely degraded in 20 min and its corresponding mineralization efficiency was 71%, the pH of solutions decreased from 10.3 to 6.47 and the dechlorination was completed in 12 min. The intermediates products of PCP in MAPC process identified by GC/MS were trichlorophenols (TCP), tetrachlorophenols (TTCP) and tetrachlorocatechol (TTCC) and the possible mechanism of PCP degradation is proposed. 相似文献
The compositional dependence of the crystalline phase and properties of precipitates (TixSn1?xO2) in the TiO2–SnO2 system, which were hydrothermally formed at 100–200 °C from the precursor solutions of TiCl4 and SnCl4 under weakly basic conditions in the presence of tetramethylammonium hydroxide (TMAH) was investigated. Rutile-type (Ti, Sn)O2 solid solutions with nano-sized crystallite were directly formed at 180 °C in the composition range of x = 0–0.8. Nanoparticles with anatase crystallite around 10 nm as a main crystalline phase of precipitates that were formed in the compositions x = 0.9 and 1.0 showed similar photocatalytic activity. As the hydrothermal treatment temperature rose from 100 to 200 °C, the crystallite size of rutile solid solution, Ti0.5Sn0.5O2, increased from 2.5 to 8.0 nm. The optical band gap of the samples changed in the range of 2.93–3.25 eV depending on their composition in the system. At the composition of x = 1.0, submicron-sized anatase-type pure TiO2 particles (sizes of cuboid sides are around 100–120 nm) with pretty high crystallinity and superior photocatalytic activity were formed from the aqueous solution of TiCl4 under basic hydrothermal condition at 180 °C in the presence of TMAH with concentration as 1.3 times high as the condition in the case of the nano-sized anatase. 相似文献
An effective photocatalytic hydrogen production catalyst comprising MgTiO3/MgTi2O5/TiO2 heterogeneous belt-junctions was prepared using magnesium ions by a thermally driven doping method. The tri-phase heterogeneous junction was confirmed by X-ray powder diffraction (XRD), transmission electron microscopy (TEM), and high-resolution TEM (HRTEM). The as-prepared MgTiO3/MgTi2O5/TiO2 heterojunctions exhibited a very high photocatalytic hydrogen production activity (356.1 mol·g0.1gcat·h-1) and an apparent quantum efficiency (50.69% at 365 nm) that is about twice of that of bare TiO2 nanobelts (189.4 mol·g0.1gcat·h-1). Linear sweep voltage and transient photocurrent characterization as well as analysis of the electrochemical impedance spectra and Mott–Schottky plots revealed that the high photocatalytic performance is caused by the one-dimensional structure, which imparts excellent charge transportation characteristic, and the MgTiO3/MgTi2O5/TiO2 tri-phase heterojunction, which effectively drives the charge separation through the inherent electric field. This titanate-based tri-phase heterogeneous junction photocatalyst further enriches the catalyst system for photocatalytic hydrogen production.