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Modification of nanocrystalline TiO <sub/>2</sub> coatings with molecularly imprinted TiO <sub/>2</sub> for uric acid recognition
摘要： Combining the surface modification and molecular imprinting technique, a novel piezoelectric sensing platform with excellent molecular recognition capability was established for the detection of uric acid (UA) based on the immobilization of TiO2 nanoparticles onto quartz crystal microbalance (QCM) electrode and modification of molecularly imprinted TiO2 (MIT) layer on TiO2 nanoparticles. The performance of the fabricated biosensor was evaluated, and the results indicated that the biosensor exhibited high sensitivity in UA detection, with a linear range from 0.04 to 45 μM and a limit of detection of 0.01 μM. Moreover, the biosensor presented high selectivity towards UA in comparison with other interferents. The analytical application of the UA biosensor confirmed the feasibility of UA detection in urine sample.
关键词： highly selective detection,uric acid biosensor,piezoelectric sensing,surface modification,molecularly imprinted TiO2
更新于2025-09-23 15:23:52
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The influence of nitrogen doping on the electronic structure of the valence and conduction band in TiO <sub/>2</sub>
摘要： X-ray emission spectroscopy (XES) and X-ray absorption spectroscopy (XAS) provide a unique opportunity to probe both the highest occupied and the lowest unoccupied states in matter with bulk sensitivity. In this work, a combination of valence-to-core XES and pre-edge XAS techniques are used to determine changes induced in the electronic structure of titanium dioxide doped with nitrogen atoms. Based on the experimental data it is shown that N-doping leads to incorporation of the p-states on the occupied electronic site. For the conduction band, a decrease in population of the lowest unoccupied d-localized orbitals with respect to the d-delocalized orbitals is observed. As confirmed by theoretical calculations, the N p-states in TiO2 structure are characterized by higher binding energy than the O p-states which gives a smaller value of the band-gap energy for the doped material.
关键词： TiO2 doping,X-ray absorption spectroscopy,electronic structure analysis,X-ray emission spectroscopy
更新于2025-09-23 15:23:52
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Synthesis of Ag nanoparticles decorated on TiO2 nanotubes for surface adsorption and photo-decomposition of methylene blue under dark and visible light irradiation
摘要： TiO2 nanotubes and Ag/TiO2 nanotubes (TNT) have been synthesized by simple hydrothermal and solvothermal method and were characterized by XRD, UV, ICP, TEM, SEM, BET and XPS. In this study the photocatlytic activity of Ag/TNT (contain 3.33% Ag) was investigated through decolorization of MB (standard methylene blue tablets for milk testing) in aqueous solution. Because of the surface plasmon resonance (SPR) effect of Ag nanoparticles, under visible light, Ag/TNT showed superior photocatalytic activity, and due to high surface area of TNT, it showed high surface absorption in dark conditions. In this study, the photocatalytic effect of Ag/TNT for the destruction and absorption of MB in aqueous solution indicated good application.
关键词： Absorption,Destruction,Ag/TiO2 nanotubes,Photocatlytic activity,MB
更新于2025-09-23 15:23:52
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Fabrication and photocatalytic performance evaluation of hydrodynamic erosion–resistant nano-TiO2–silicone resin composite films
摘要： Herein, we present the preparation of nano-TiO2–silicone resin composite films by double liquid phase spray deposition. The films exhibit better adhesion stability and photocatalytic activity under a hydrodynamic erosion condition than conventional nano-TiO2 composite films. The TiO2 layer morphology and effective TiO2 coverage ratio (CR) were affected by the initial curing time (ICT) of the silicone resin, e.g., the increase in an ICT from 10 to 40 min resulted in a CR change from 79.1 to 98.7%. The surface morphology evolution of composite films was studied under a hydrodynamic erosion period of 4 weeks. Obtained results allowed the 4-week evolution to be divided into four stages (pitting, crack pregnant, banded stripping, and surface stripping periods), additionally revealed that the CR of all samples was remained above 65%. The photocatalytic activity of composite films before and after 4-week hydrodynamic erosion was evaluated by rhodamine B degradation experiments. The 4-week erosion only led to the decrease of the photodegradation efficiencies by less than 40% in all cases. Thus, the fabricated TiO2–silicone composite films demonstrated excellent durability and photocatalytic activity under the conditions of long-term hydrodynamic erosion, allowing one to conclude that this work paves the way to the fabrication of next-generation photocatalytic materials for industrial applications.
关键词： Photocatalysis,Film formation mechanism,Silicone resin,Photodegradation,Hydrodynamic erosion resistance,Nano-TiO2
更新于2025-09-23 15:23:52
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Enhanced photocatalytic activity of TiO2/graphene by tailoring oxidation degrees of graphene oxide for gaseous mercury removal
摘要： We used a simple method of graphene oxide (GO) preparation with different oxidation levels, and control the properties of the TiO2 nanocrystals by tuning the content and oxidation degree of GO to enhance the photocatalytic performance. During the hydrothermal reaction, reduction of GO, formation of TiO2 and chemical bonds between TiO2 and reduced graphene oxide (RGO) was achieved simultaneously. Characterization results showed that TiO2 properties such as crystalline grain and particle size could be tailored by the amount of functional groups, and that crystallinity was also controlled by GO degrees of oxidation. TiO2/RGO photocatalysts showed great efficiency of mercury oxidation, which reached 83.7% and 43.6% under UV and LED light irradiation, respectively. The effects of crystalline grain size and surface chemical properties on Hg0 removal under LED and UV light irradiation were analyzed. In addition, the properties of the photocatalysts before and after UV illumination were investigated, finding that part of Ti-OH on TiO2 surface transformed to Ti-O-Ti. In a nutshell, this work could provide a new insight into enhancing activity of photocatalysts and understanding the photocatalytic mechanism.
关键词： TiO2,Photocatalysis,Chemical Bonds,Elemental Mercury,Reduced Graphene Oxide
更新于2025-09-23 15:23:52
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Photocatalytic Degradation of Bisphenol A Induced by Dense Nanocavities Inside Aligned 2D-TiO2 Nanostructures
摘要： The preparation of materials with aligned porosity in the nanometer range is of technological importance for a wide range of applications in molecular filtration, biomaterials and catalysis. Herein we present the advantages offered by cryo – lyophilisation technique as a smart and green non-standard concept to produce dense regular polyhedral nanocavities inside the 2D TiO2 nanosheets. Hierarchical morphologies of nanocavities start to appear at temperature higher than 800 °C and are strongly influenced by polymorph TiO2 evolution competing reactions. The small angle X-ray scattering (SAXS) analysis confirms self-assembled 3D nanocavities with size range from 5 to 10 nm in both length and width, and depth ~ 3.6 nm formed after realising of the confined ice-water. It was found that nanocavities enhance significantly the absorption properties of TiO2 in the UV region, thereby providing a new approach to increase the photoreactivity of 2D TiO2 nanosheets. The annealed precursors containing aqueous solution of peroxo polytitanic acid (PPTA) at 800 °C exhibited the highest photoactivity in degrading bisphenol A (BPA) due to evenly distributed nanocavities inside single anatase TiO2 nanocrystals interconnected and aligned onto the 2D TiO2 nanosheet arrays.
关键词： emerging pollutants,nanoconfined water,photocatalysis,nanocavities,freeze-drying,anatase TiO2
更新于2025-09-23 15:23:52
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Study on the enhancement of photocatalytic environment purification through ubiquitous-red-clay loading
摘要： Tungsten oxide (WO3) is regarded as a promising visible-light-sensitive photocatalyst, but its activity is not high. Further enhancement of its activity has been anticipated using techniques such as loading of a cocatalyst to apply the oxide to indoor environmental remediation; Pt has been reported as a good cocatalyst for WO3 photocatalysis. However, Pt is precious and expensive metal. Thus, in this study, we sought to find a ubiquitous cocatalyst and suitable photocatalyst system. As a result, this study revealed that loading a ubiquitous material of red-clay enhanced WO3 photocatalytic activity remarkably. As photocatalyst samples, mixtures consisting of the clay and WO3 with different weight ratios were prepared using a simple kneading method. Their photocatalytic activity was evaluated from decomposition of harmful organic contaminant, 2-propanol into CO2 under visible-light irradiation. The WO3 with 10% of the clay loading showed the highest activity among the samples and much higher activity than pure WO3. This higher activity might derive from the clay’s promotion of H2O2 decomposition and charge separation (holes and electrons). The H2O2 was generated from photocatalytic O2 reduction. This formation and accumulation on the pure WO3 surface led to decreased activity.
关键词： TiO2,Zeolite,Natural mineral,Optical absorption,Remediation
更新于2025-09-23 15:23:52
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[Mo3S13]2? modified TiO2 coating on non-woven fabric for efficient photocatalytic mineralization of acetone
摘要： Improving the photocatalytic efficiency of commercial TiO2 has important significance for practical application of TiO2 based photocatalysts. A novel photocatalyst [Mo3S13]2?/TiO2 was fabricated by combining [Mo3S13]2? with commercial TiO2 by an impregnation method. This composite photocatalyst presented a remarkable enhancement on photocatalytic mineralization of acetone in comparison with commercial TiO2. The optimum loading amount of [Mo3S13]2? was 1.7wt%, which is more efficient than the Pt/TiO2 (1.5wt%). Electrochemical impedance spectroscopy (EIS) showed the smooth electron transfer pathway in [Mo3S13]2?/TiO2 composite, facilitating the photo-charges separation during the photocatalysis process. Reactive oxygen species scavenging test illustrated that superoxide radical (?O2?), hydroxyl radical (?OH) and photo-induced hole (h+) were all contributing to the acetone degradation. The [Mo3S13]2?/TiO2 photocatalyst was deposited on non-woven fabrics which showed obvious promotion on the photocatalytic degradation of acetone in comparison with pristine commercial TiO2.
关键词： TiO2,[Mo3S13]2?,Photocatalytic oxidation,VOCs degradation,Non-woven fabrics
更新于2025-09-23 15:23:52
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2D-montmorillonite-dispersed g-C3N4/TiO2 2D/0Dnanocomposite for enhanced photo-induced H2 evolution from glycerol-water mixture
摘要： Montmorillonite (MMT) dispersed g-C3N4/TiO2 hybrid nanocomposite for enhanced photo-catalytic hydrogen production from glycerol-water mixture has been investigated. The newly designed composite photo-catalysts were fabricated through a sol-gel assisted hydrothermal method and were characterized by XRD, XPS, SEM, EDX, TEM, FTIR, UV–Vis, Raman and PL spectroscopy. Well-designed g-C3N4/MMT/TiO2 heterojunction composite was obtained with 2D MMT structure, which promoted both visible light absorption and hindered charges recombination rate. The modification of 2D/0D g-C3N4/TiO2 heterojunction with 2D MMT sheets enhances H2 production due to MMT works as a mediator for effective charges trapping and transportation within the composite structure. The g-C3N4/MMT/TiO2 photo-catalyst exhibits highest H2 production of 4425 ppm h?1 g?1 at pH 7.0, which was 2.12 times higher than the pure TiO2 (2085 ppm h?1 g?1). In addition, increasing catalyst loading promotes more H2 evolution and among the different sacrificial reagents, glycerol-water mixture gave highest H2 production due to the presence of α-hydrogen atoms attached to carbon atoms. The enhanced photocatalytic efficiency can be attributed to synergistic effect of MMT with g-C3N4/TiO2 heterojunction composite, appropriate band structure and transportation of electrons–holes with their hindered recombination rate. These composite catalysts exhibited excellent photo-catalytic stability for H2 production in cyclic runs. Possible reaction mechanism for hydrogen production over g-C3N4/MMT/TiO2 composite has been explained based on the experimental results. The finding of this work would be fruitful for hydrogen production applications with all sustainable systems.
关键词： TiO2,Photo-catalysis,Montmorillonite,g-C3N4,Z-scheme,Hydrogen production
更新于2025-09-23 15:23:52
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Photocatalysis as an advanced reduction process (ARP): the reduction of 4-nitrophenol using titania nanotubes-ferrite nanocomposites
摘要： TiO2 photocatalysis is an advanced process, employed worldwide for the oxidation of organic compounds, that leads to significant technological applications in the fields of health and environment. The use of the photocatalytic approach in reduction reactions seems very promising and can open new horizons for green chemistry synthesis. For this purpose, titanium dioxide nanotubes (TNTs) were developed in autoclave conditions using TiO2 P25 as a precursor material. Based on these nanotubular substrates, TiO2/CoFe2O4 (TCF) nanocomposites were further obtained by wet impregnation method. The materials were thoroughly characterized and their structural, textural, vibrational, optoelectronic and magnetic properties were determined. The composite materials combine absorbance in the visible optical range and high BET surface area values (~100 m2/g), showing extremely high yield in the photocatalytic reduction of 4-nitrophenol (4-NP), exceeding 94% within short illumination time (only 35 min). The developed nanocomposites were successfully reused in consecutive photocatalytic experiments and were easily removed from the reaction medium using magnets. Both remarkable recycling ability and high-performance stability in the photocatalytic reduction of nitrophenol were observed, thus justifying the significant economic potential and industrial perspectives for this advanced reduction process.
关键词： Cobalt ferrite,4-nitrophenol reduction.,Nanocomposite photocatalyst,TiO2 nanotubes
更新于2025-09-23 15:23:52