scholarly journals One-Step Synthesis of Ag@TiO2 Nanoparticles for Enhanced Photocatalytic Performance

Nanomaterials ◽  
2018 ◽  
Vol 8 (12) ◽  
pp. 1032 ◽  
Author(s):  
Yufan Zhang ◽  
Fan Fu ◽  
Yuzhou Li ◽  
Desuo Zhang ◽  
Yuyue Chen

Polyamide network polymers (PNP) modified TiO2 nanoparticles (NPs) were decorated with Ag NPs in hydrothermal gel method, forming one-step synthesized photocatalysts, Ag@TiO2 NPs. The effect of PNP and the amount of Ag NPs added were investigated in this work. PNP acted as a nanocage to prevent TiO2 aggregation and capture Ag accurately, which could effectively control product sizes and improve dispersibility in solvents. Simultaneously, TiO2 NPs modified with Ag NPs exhibited remarkable photocatalytic effects. One-step synthesis simplified the experimental process and avoided the agglomeration of silver ions during the secondary reaction, achieving the purpose of uniform distribution at a specific location of TiO2 NPs. The prepared Ag@TiO2 NPs-0.5 could remove 79.49% of Methyl Orange (MO) after 3 h of ultraviolet light irradiation, which was 2.7 times higher than the reaction rate of pure TiO2 NPs. It also exhibited good photoactivity under Visible light conditions. Moreover, the mineralization rate of MO over the Ag@TiO2 NPs-0.5 could be up to 72.32% under UV light and 47.08% under Visible light irradiation, which revealed that the prepared catalysts could effectively degrade most of the MO to CO2 and H2O. The samples also demonstrated the excellent stability and easy recyclability with over 90% of the original catalytic level for MO degradation. The photocatalysts studied also exerted broad application prospects such as photovoltaic hydrogen production, electronic sensors and biomedicine.

2015 ◽  
Vol 24 (4) ◽  
pp. 363
Author(s):  
Le Ha Chi ◽  
Pham Duy Long ◽  
Nguyen Van Chuc ◽  
Le Van Hong

TiO2 is one of the most attractive metal oxides because of the excellent chemical and photocatalytic properties. However, a problem in the application of TiO2 is the large band gap energy of 3.2 eV, corresponding to its photocatalytic activity under UV-light irradiation of wavelengths <387 nm. In this work, TiO2 nanoparticles doped with iron were grown on the surface of functionalized carbon nanotubes (TiO2-Fe@CNTs) to expand the photoabsorbance of the nanocomposite materials in the visible light region and improve their photocatalytic activity. TiO2-Fe@CNTs nanocomposite materials were synthesized by hydrothermal route in Teflon-sealed autoclave at 180oC for 10h. The FE-SEM and X-Ray diffraction measurements were taken for morphology and structural analysis of TiO2 nanoparticles doped with Fe coating on CNTs. The effects of the iron and CNTs on the enhanced photocatalytic activity for methylene blue degradation under AM 1.5 illumination of 100 mW.cm−2 were investigated.


Catalysts ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 235
Author(s):  
Hayette Benkhennouche-Bouchene ◽  
Julien G. Mahy ◽  
Cédric Wolfs ◽  
Bénédicte Vertruyen ◽  
Dirk Poelman ◽  
...  

TiO2 prepared by a green aqueous sol–gel peptization process is co-doped with nitrogen and zirconium to improve and extend its photoactivity to the visible region. Two nitrogen precursors are used: urea and triethylamine; zirconium (IV) tert-butoxide is added as a source of zirconia. The N/Ti molar ratio is fixed regardless of the chosen nitrogen precursor while the quantity of zirconia is set to 0.7, 1.4, 2, or 2.8 mol%. The performance and physico-chemical properties of these materials are compared with the commercial Evonik P25 photocatalyst. For all doped and co-doped samples, TiO2 nanoparticles of 4 to 8 nm of size are formed of anatase-brookite phases, with a specific surface area between 125 and 280 m2 g−1 vs. 50 m2 g−1 for the commercial P25 photocatalyst. X-ray photoelectron (XPS) measurements show that nitrogen is incorporated into the TiO2 materials through Ti-O-N bonds allowing light absorption in the visible region. The XPS spectra of the Zr-(co)doped powders show the presence of TiO2-ZrO2 mixed oxide materials. Under visible light, the best co-doped sample gives a degradation of p-nitrophenol (PNP) equal to 70% instead of 25% with pure TiO2 and 10% with P25 under the same conditions. Similarly, the photocatalytic activity improved under UV/visible reaching 95% with the best sample compared to 50% with pure TiO2. This study suggests that N/Zr co-doped TiO2 nanoparticles can be produced in a safe and energy-efficient way while being markedly more active than state-of-the-art photocatalytic materials under visible light.


2017 ◽  
Vol 4 (10) ◽  
pp. 1691-1696 ◽  
Author(s):  
Mumei Han ◽  
Huibo Wang ◽  
Siqi Zhao ◽  
Lulu Hu ◽  
Hui Huang ◽  
...  

10%CoO/g-C3N4 exhibits good photocatalytic performance under visible light irradiation without any sacrificial reagents.


2014 ◽  
Vol 886 ◽  
pp. 183-186
Author(s):  
Xiao Dong Zhang ◽  
Sha Sha Wei ◽  
Shou Zhi Pu

An unsymmetrical photochromic diarylethene 1-(2-methyl-1-phenyl)-2-[2-methyl-5-(4-formylphenyl)-3-thienyperfluoroyclopentene (1o) was designed and constructed successfully. Its photochromic properties were examined. The results showed that the compound exhibits good photochromism with UV/Vis light irradiation. The diarylethene 1o changed the color from colorless to blueviolet upon irradiation with 297 nm UV light, in which absorption maxima were observed at 549 and 581nm in hexane and PMMA films, respectively.The photochromic cyclization/cycloreversion kinetics of 1o in hexane were determined by UV-Vis spectra upon alternating irradiation with UV and appropriate wavelength visible light.


2018 ◽  
Vol 43 (9) ◽  
pp. 4335-4346 ◽  
Author(s):  
Yang Li ◽  
Liyuan Kuang ◽  
Dequan Xiao ◽  
Appala Raju Badireddy ◽  
Maocong Hu ◽  
...  

Nanomaterials ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 987 ◽  
Author(s):  
Hui Zhang ◽  
Qi Tang ◽  
Qingshan Li ◽  
Qingwen Song ◽  
Hailiang Wu ◽  
...  

In this study, the effects of disperse blue dye-sensitization on the photocatalytic properties of the Ag-N co-doped TiO2 nanoparticles loaded on polyethylene terephthalate (PET) filaments are investigated under visible light irradiation. The microstructure and photocatalytic properties of the as-synthesized TiO2 nanocomposites, as well as the as-prepared PET filaments, are systematically characterized. The photocatalytic performance of the PET filaments coated with the Ag-N co-doped TiO2 nanoparticles sensitized with disperse blue dyes is evaluated via its capacity of photo-degrading methyl orange (MO) dyes under visible light irradiation. It is found that the holes are the predominant reactive radical species and the hydroxyl and superoxide radicals play a subordinate role in the photocatalytic reaction process. The reaction rate constant of the photocatalytic composite filaments is nearly 4.0 times higher than that of the PET filaments loaded solely with TiO2 nanoparticles. The resultant photocatalytic composite filaments are evident to be capable of repeatedly photo-degrading MO dyes without losing its photocatalytic activity significantly.


2017 ◽  
Vol 53 (10) ◽  
pp. 1692-1695 ◽  
Author(s):  
Akila Iyer ◽  
Steffen Jockusch ◽  
Jayaraman Sivaguru

To address the problem of using UV light to initiate traditional photoreactions, hydrazide based chromophores are evaluated as a “photo-auxiliary“ with visible light using a metal free photocatalyst to afford photoproducts in high yields.


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