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Osteoblast Response to Different UVA-Activated Anatase Implant Coatings
摘要： The “activation” of titanium implants by UV-irradiation is reported to enhance osseointegration in vitro as well as in vivo. Anatase-enriched titanium oxide surfaces enable, via photocatalysis, a chairside “activation” of implants by short-term UVA (382 nm) irradiation. The potentially improved clinical performance of these modified surfaces depends not only on the achieved photocatalytic activity, but also on the effects caused by the micro- and nano-structure of the respective surface modification. In this study, three differently manufactured anatase-coated titanium surfaces are characterized regarding surface characteristics, photocatalytic efficiency, and their ability to promote proliferation and differentiation of osteoblasts in comparison to conventional sandblasted (S) and blasted/etched (S/A) titanium implant surfaces. Anatase surfaces are manufactured by suspension plasma spraying (SPS), precursor-based liquid film coating (PLC), and physical vapor deposition (PVD). The tested surfaces exhibit significantly different surface morphologies and anatase/rutile ratios. UVA-irradiation of samples prior to cell seeding leads to significantly improved cell proliferation and surface coverage. UVA-treatment also leads to a generally enhanced osteoblastic differentiation of cells on all anatase-coated surfaces. The anatase-enriched titanium surface modifications promote different aspects of osteoblast reactions, suggesting that the “activation” of anatase-coated titanium implants by UVA treatment is a promising chairside procedure for dental implant optimization.
关键词： anatase,osteoblasts,titanium implant activation,hydrophilization,photocatalysis
更新于2025-09-04 15:30:14
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Photocatalytic Degradation of Methylene Blue using Biosynthesized Zinc Oxide Nanoparticles from Bark extract of Kalopanax septemlobus
摘要： In this study, we applied Kalopanax septemlobus-ZnO nanoparticles (Ks-ZnO NPs) with green approach one-pot synthesis. Further, the extracts were used as capping agent and Zn (OAc)2 as the metal precursor to synthesize ZnO nanoparticles. The formation of ZnO NPs, the surface plasmon resonance were observed at 372 nm in UV-Vis spectroscopy. The presence of functional groups which as a capping agent and formation of ZnO nanoparticles were confirmed in Fourier Transform Infrared Spectroscopy (FTIR) result. The crystallization, elemental mapping and morphology showed by X-ray diffraction (XRD), Field-Emission Transmission Electron Microscopy (FE-TEM), and Energy dispersive X-ray spectroscopy (EDX) respectively. The photocatalytic activity of Ks-ZnO nanoparticles, was determined using Methylene blue dye degradation percentage under UV light irradiation (365nm), which resulted rate constant (k) was found 0.1215 with 97.5% of degradation in 30 minutes. In summary, phytochemicals in K. septemlobus extract have a potential as a reducing agent to form Ks-ZnO nanoparticles. The Ks-ZnO NPs are capable to degrade Methylene blue in brief time due to its extract-capped zinc oxide nanoparticles. Accordingly, the use of K. septemlobus for biosynthesis of nanoparticles may have an advance for many applications as a cost-effective and eco-friendly photocatalyst.
关键词： methylene blue,Kalopanax septemlobus,photocatalysis,nanoparticles,zinc oxide
更新于2025-09-04 15:30:14
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Preparation of TiO2 Microspheres with Tunable Pore and Chamber Size for Fast Gaseous Diffusion in Photoreduction of CO2 under Simulated Sunlight
摘要： TiO2 microsphere with tunable pore and chamber size are prepared by a simple solventhermal method and used as catalyst for the photocatalytic CO2 reduction. It is found that the hollow microsphere with relative lower surface area of 73.8 m2g-1 exhibits increased pore size of 18.1 nm and cavity structure, leading to higher CO2 diffusion coefficient of 5.40×10-5 cm2s-1 compared with the solid and yolk/shell microspheres. Therefore, the hollow microsphere possesses more accessible sites for CO2 adsorption, which finally gives rise to the enhanced CO production rate of 10.9±0.7 μmolg-1h-1 under simulated sunlight, which is respectively 1.6 and 1.4 times higher than that of solid and yolk/shell microspheres. Electron dynamic study further demonstrates that hollow microsphere shows the highest photocurrent density and the lowest charge recombination among three microspheres structure, which is attributed to the swift CO2 diffusion providing fresh CO2 molecules to rapidly scavenge the photo-generated electrons and finally leading to the excellence catalytic reduction performances. This method could be adopted as a general strategy to prepare high performance TiO2 catalysts with desirable structural qualities for the photocatalytic CO2 reduction under nature sunlight.
关键词： TiO2,CO2 reduction,Hollow structures,Photocatalysis,Mass transport
更新于2025-09-04 15:30:14
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Integration of Metallic TaS <sub/>2</sub> Co-catalyst on Carbon Nitride Photoharvester for Enhanced Photocatalytic Performance
摘要： The efficient separation of photogenerated electron-hole (e--h+) pairs is the key point for photocatalytic reactions. The integration of co-catalysts, especially noble-metals, can improve the e--h+ separation efficiency dramatically. However, the high-cost would limit their large-scale application. Therefore, the exploration of noble-metal-free co-catalysts is still important for the development of photocatalysis. In this work, we report a series of metallic TaS2 based catalysts that can effectively boost the photocatalytic performance of a metal-free semiconductor (2D-C3N4). The advantages of the as-prepared catalysts were demonstrated as follows: (i) noble-metal-free; (ii) outstanding electrical conductivity; and (iii) superior stability. As demonstrated in photocatalytic degradation reaction, the optimal removal rate of pollutant Rhodamine B (RhB) reached to 92 % after 100 min of irradiation, which is enhanced by almost 25 % more than pure two-dimensional graphitic carbon nitride nanosheets (2D-C3N4). This work may provide insight into finding new low-cost metallic materials as co-catalyst to promote phototcatalytic performance. This article is protected by copyright. All rights reserved
关键词： TaS2,2D-C3N4,photocatalysis,co-catalyst
更新于2025-09-04 15:30:14
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Magnetic photocatalysts from industrial residues and TiO2 for the degradation of organic contaminants
摘要： In this study, magnetic photocatalysts were prepared with different levels of TiO2 supported on tar pitch and red mud (RM) (40, 60, 80Ti/C/RM), which were used as carbon (C) and iron sources, respectively. The characterization by TEM, SEM and energy dispersive X-ray spectrometry showed that the RM particles are distributed in the bulk and on the surface of the carbonaceous matrix, forming the C/RM composite. These characterizations also confirmed the presence of TiO2 particles agglomerated on the photocatalysts surface. XDR results showed that the goethite and hematite in the RM was reduced to Fe3O4 and elemental analysis and Raman spectroscopy confirmed the carbon matrix. The obtained photocatalysts showed high efficiency to discolor the remazol black B dye (RB5). The 60 and 80Ti/C/RM photocatalysts decolorized 99% of the RB5 dye in reaction with solar radiation, while sample 40Ti/C/RM discolored 83%. The reactions performed with UV light showed that the 40, 60 and 80Ti/C/UV photocatalysts, decolorized 36, 60, and 71% of the RB5 and reduce 13, 34 and 52% of total organic carbon (TOC), respectively. Magnetic separation was preceded and the characterizations of the magnetic (MF) and non-magnetic fraction (NMF) confirmed that about 25% of TiO2 did not fix in the 60Ti/C/RM photocatalyst. MF and NMF decolorized 70 and 80% of the RB5, respectively, at the photocatalytic reaction (UV light). Sedimentation kinetics showed that photocatalysts are separated faster from aqueous environment than pure TiO2.
关键词： Tar Pitch,Degradation,Red mud,Photocatalysis,Titanium Oxide
更新于2025-09-04 15:30:14
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Mechanistic insights into light-activated catalysis for water oxidation
摘要： The development of catalysts for water oxidation to oxygen has been the subject of intense investigation in the last decade. In parallel to the search for high catalytic performance, many works have focused on the mechanistic analysis of the process. In this perspective, the oxidation of water through light-assisted cycles composed of an electron acceptor (EA), a photosensitizer (PS), and a water oxidation catalyst (WOC) can provide insightful and complementary information with respect to the use of chemical oxidants or to electrochemical techniques. In this microreview, we discuss the mechanistic aspects of the EA/PS/WOC photoactivated cycles, and in particular: (i) the general elementary steps; (ii) the required features and the nature of the PS employed; (iii) the electron transfer processes and kinetics from the WOC to PS+ (hole scavenging); (iv) the detrimental quenching of the PS by the WOC and the alternative mechanistic routes; (v) the identification of WOC intermediates and, finally, (vi) the transposition of the above processes into a dye-sensitized photoanode embedding a WOC.
关键词： reaction mechanisms,intermediates,water oxidation,Electron transfer,photocatalysis
更新于2025-09-04 15:30:14
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Upconversion Tm3+:CeO2/Palygorskite as direct Z-scheme heterostructure for photocatalytic degradation of bisphenol A
摘要： Novel Tm3+:CeO2/palygorskite (Pal) nanocomposites were prepared by a hydrothermal-deposition method. X-ray diffraction (XRD), transmission electron microscopy (TEM), UV-Vis spectrum（UV-Vis）, photoluminescence spectroscopy（PL）and Mott-Schottky analysis were employed to characterize the products. Results indicated that Pal skeleton possessed abundant adsorption sites and shortened band gap after modified by hydrochloric acid. Tm3+ doping enhanced the utilization of solar light due to its upconversion from visible to ultraviolet light. Meanwhile, the adsorption edge of the Tm3+:CeO2 was extended to visible region with the formation of heterojunctions. The product intimated Tm3+:CeO2/Pal behaved strongest upconversion luminescence when the doping fraction of Tm3+ was optimized to be 0.02, and the photocatalytic degradation of bisphenol A (BPA) reached 86 % when the mass content of Tm3+:CeO2 as compared to Pal was optimized to 10 wt%. The direct Z-scheme system was constructed between Pal and Tm3+:CeO2 leading to the improved charge-separation efficiency and maintenance of high redox potential.
关键词： CeO2,Upconversion,Palygorskite,Photocatalysis,Z-scheme
更新于2025-09-04 15:30:14
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Structure, Optical, and Photocatalytic Properties of Oxynitride Solid Solutions Ca <sub/> 1- <i>x</i> </sub> Sr <i> <sub/>x</sub></i> NbO <sub/>2</sub> N, CaNb <sub/> 1- <i>x</i> </sub> Ta <i> <sub/>x</sub></i> O <sub/>2</sub> N, and SrNb <sub/> 1- <i>x</i> </sub> Ta <i> <sub/>x</sub></i> O <sub/>2</sub> N Prepared from Soft-Chemistry Precursors
摘要： Three perovskite oxynitride solid solutions Ca1–xSrxNbO2N, CaNb1–xTaxO2N, and SrNb1–xTaxO2N were prepared by low temperature ammonolysis of soft-chemistry precursors. In particular, we present for the first time a way to synthesize the substitution series Ca1–xSrxNbO2N, which cannot be prepared by ammonolysis of classical solid state precursors. All samples were phase-pure and exhibit bandgaps in the visible light range that can be tailored by substitutions both of the A- and B-type cations. Rietveld analysis was applied to determine cell parameters and crystal structures. In the case of Ca1–xSrxNbO2N a structural change from orthorhombic to tetragonal was found. After loading with CoOx the photocatalytic activities in the solution-based methyl orange degradation were investigated and for SrNb1–xTaxO2N a considerable activity was found.
关键词： Perovskites,Photocatalysis,Oxynitrides,Hydrothermal synthesis,X-ray diffraction
更新于2025-09-04 15:30:14
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Synthesis and characterization of MnWO4/TmVO4 ternary nano-hybrids by an ultrasonic method for enhanced photocatalytic activity in the degradation of organic dyes
摘要： In this study, novel MnWO4/TmVO4 ternary nano-hybrids were synthesized effectively via a simple sonochemical method. The products were characterized in detail with the use of modern analytical techniques including XRD, EDX, TEM, DRS, BET, PL, and VSM. To the authors’ best knowledge, this is the first report on the synthesis and photocatalytic performance of MnWO4/TmVO4 ternary nano-hybrids in the degradation of rhodamine B (Rh B), 2-naphthol (Na), phenol red (Ph R), and eosin Y (EY) under visible light. Based on the degradation results, MnWO4/TmVO4 is shown to have higher photodegradation ability than pure TmVO4 or MnWO4 nanoparticles. It was also found that maximum degradation (99.2%) is achieved in the case of Rh B dye.
关键词： Semiconductors,MnWO4/TmVO4,Ternary nano-hybrids,Photocatalysis,Luminescence
更新于2025-09-04 15:30:14
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Facile Synthesis of Ag/ZnO Photocatalysts on the Degradation of Diuron Herbicide Under Simulated Solar Light and the Investigation of Its Antibacterial Activity for Waste-Water Treatment
摘要： Nanocrystalline Ag/ZnO powders have been successfully prepared by a modified polyol process using triethylene-glycol (TEG) as solvent, reducing and stabilizing agent. The synthesis procedure has been conducted without any post-synthesis thermal treatment. The structural and optical properties have been characterized by X-ray diffraction, transmission electron microscopy, N2 adsorption study, inductively coupled plasma optical emission spectroscopy and UV–Vis diffuse reflectance spectroscopy. The photocatalytic activity of Ag/ZnO materials has been studied by analyzing the degradation of an herbicide, diuron, under solar light. Ag/ZnO photocatalysts with optimized x = 0.7% Ag content showed 14 times higher rate of degradation than that of unmodified ZnO. We attribute these observations to the addition of silver nanoparticles allowing interfacial oxide-to-metal electron transfer within the hybrid Ag/ZnO photocatalyst. The inhibitory and bactericidal activities of samples have been tested against Gram-negative bacteria; Escherichia coli, Salmonella typhimurium and gram-positive bacteria; Staphylococcus aureus, Enterococcus faecium and Candida albicans. The results showed that the Ag/ZnO can be used as photocatalysts and antibacterial agents for potential practical applications in the wastewater treatment.
关键词： Nanoparticles,Photocatalysis,Antibacterial,ZnO,Wastewater treatment,Ag
更新于2025-09-04 15:30:14