scholarly journals Development of Photocatalytic 3D-Printed Cementitious Mortars: Influence of the Curing, Spraying Time Gaps and TiO2 Coating Rates

Buildings ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 381
Author(s):  
Behzad Zahabizadeh ◽  
Iran Rocha Segundo ◽  
João Pereira ◽  
Elisabete Freitas ◽  
Aires Camões ◽  
...  

This work evaluated the photocatalytic activity of 3D-printed cementitious mortar specimens functionalized with TiO2 nanoparticles to obtain a multifunctional and smart concrete. This research aims to assess the influence of different parameters related to the functionalization process such as adsorption, coating time gaps, and coating rates on the degradation efficiency of the functionalized cementitious specimens. Each specimen was evaluated under the degradation of Rhodamine B (RhB) in an aqueous solution using a sun-light simulation. The obtained results showed a decrease in adsorption (under dark condition) with increasing the sample curing age. The highest photocatalytic efficiency was observed for coated samples aged 7 days. By increasing the coating rates, the photocatalytic efficiency is enhanced. Nonetheless, regardless of the coating rates, all the specimens showed an increase in photocatalytic efficiency for longer time periods of light exposition, i.e., after 8 h of irradiation.

2015 ◽  
Vol 1118 ◽  
pp. 211-216
Author(s):  
Yuan Liang Ma ◽  
Xue Rong Zheng ◽  
Wei Liu ◽  
Hai Qin Li ◽  
Hui Ming Ji

Pure phase of Yb3+/Er3+ co-doped β-NaYF4 micron tubes with up-conversion fluorescence were synthesized by hydrothermal method at 180°C for 24 hours. For better utilization of sunlight and improving photocatalytic efficiency of organic dyes, TiO2 nanoparticles were modified by combining with β-NaYF4 micron tubes to form TiO2/NaYF4 composite. Three different combination methods were studied and the photocatalytic activities of the corresponding samples were tested by measuring the degradation rate of rhodamine aqueous solution under illumination of simulated sunlight. The composite that TiO2 nanoparticles were well dispersed on the surface of NaYF4 shows better photocatalytic activity than other composites and was near twice efficiency of pure TiO2 nanoparticles. The reason may be due to the high activity of heterostructure for TiO2/NaYF4 composite that will make it easy for sunlight absorption and photocatalytic degradation.


2009 ◽  
pp. 125-133 ◽  
Author(s):  
Eva Loncar ◽  
Miroslava Radeka ◽  
Snezana Petrovic ◽  
Andrea Skapin ◽  
Ognjen Rudic ◽  
...  

The photocatalytically active mesoporous coatings, based on titanium dioxide sols (Degussa), of the fired clay roofing tiles substrate were prepared by using poly(ethylene glycol) (PEG) M-600 and M-4000, as the structure directing agents. The coatings were deposited using spray technique followed by thermal treatment. Photocatalytic activity of the TiO2 coatings was evaluated by aqueous solution of methylene blue as model dye, deposited on the top of the coatings, after irradiation with UV light. The results were compared with the photocatalytic efficiency of some commercial self-cleaning products (clay roofing tiles, glass). The newly design coatings showed an interesting decolourisation performance (over 30 % after 24 h). It appeared that the procedure of photocatalytic activity determination, in the case of porous substrates, should be renewed by a preadsorption process.


2018 ◽  
Vol 6 (1) ◽  
pp. 22-30
Author(s):  
C. Lalhriatpuia ◽  
◽  
Thanhming liana ◽  
K. Vanlaldinpuia

The photocatalytic activity of Nanopillars-TiO2 thin films was assessed in the degradation of Bromophenol blue (BPB) dye from aqueous solution under batch reactor operations. The thin films were characterized by the XRD, SEM and AFM analytical methods. BET specific surface area and pore sizes were also obtained. The XRD data showed anatase phase of TiO2 particles with average particle size of 25.4 and 21.9 nm, for S1 and S2 catalysts respectively. The SEM and AFM images indicated the catalyst composed with Nanosized pillars of TiO2, evenly distributed on the surface of the substrate. The average height of the pillars was found to be 180 and 40 nm respectively for the S1 and S2 catalyst. The BET specific surface area and pore sizes of S1 and S2 catalyst were found to be 5.217 and 1.420 m2/g and 7.77 and 4.16 nm respectively. The photocatalytic degradation of BPB using the UV light was studied at wide range of physico-chemical parametric studies to determine the mechanism of degradation as well as the practical applicability of the technique. The batch reactor operations were conducted at varied pH (pH 4.0 to 10.0), BPB initial concentration (1.0 to 20.0 mg/L) and presence of several interfering ions, i.e., cadmium nitrate, copper sulfate, zinc chloride, sodium chloride, sodium nitrate, sodium nitrite, glycine, oxalic acid and EDTA in the photocatalytic degradation of BPB. The maximum percent removal of BPB was observed at pH 6.0 and a low initial concentration of the pollutant highly favours the photocatalytic degradation using thin films. The presence of several interfering ions suppressed the photocatalytic activity of thin films to some extent. The time dependence photocatalytic degradation of BPB was demonstrated with the pseudo-first-order rate kinetics. Study was further extended with total organic carbon measurement using the TOC (Total Organic Carbon) analysis. This demonstrated an apparent mineralization of BPB from aqueous solutions.


RSC Advances ◽  
2017 ◽  
Vol 7 (80) ◽  
pp. 50546-50554 ◽  
Author(s):  
Rong Li ◽  
Chencen Sun ◽  
Jia Liu ◽  
Qiang Zhen

Magnetic recovery S-CoFe2O4 nanopowders showed excellent visible photocatalytic degradation of oxytetracycline and recycling performances in aqueous solution.


2021 ◽  
Vol 3 (2) ◽  
Author(s):  
Denise S. Cordeiro ◽  
Fernando L. Cassio ◽  
Larissa Ciccotti ◽  
Thiago L. R. Hewer ◽  
Paola Corio ◽  
...  

AbstractPraseodymium doped TiO2 nanoparticles were successfully prepared by the sol–gel method and characterized by X-ray powder diffraction, N2 adsorption–desorption isotherm, and UV–vis spectroscopy. The effects of the dopant on the crystallite size, specific surface area, average pore diameter, pore volume, and bandgap energy were investigated. The photocatalytic activity of the catalysts was evaluated by bisphenol A degradation and mineralization, which is a representative endocrine disruptor. Furthermore, under visible light irradiation the Pr-modified TiO2 photocatalysts exhibited higher photocatalytic efficiency than unmodified TiO2. When praseodymium was loaded (1.0–5.0%) onto the surface of TiO2, the rates of degradation and mineralization were increased 3–5 times.


2016 ◽  
Vol 19 (1) ◽  
Author(s):  
Xinlu Liu ◽  
Junbo Zhong ◽  
Jianzhang Li ◽  
Wei Hu ◽  
Qizhao Wang ◽  
...  

AbstractIn this paper, α-Fe


RSC Advances ◽  
2021 ◽  
Vol 11 (17) ◽  
pp. 10300-10308
Author(s):  
Hui Feng ◽  
Siqi Feng ◽  
Niu Tang ◽  
Songbai Zhang ◽  
Xiangyang Zhang ◽  
...  

New idea for the low cost synthesis of high performance photocatalysts for the photodegradation of organic pollutants in aqueous solution.


RSC Advances ◽  
2016 ◽  
Vol 6 (95) ◽  
pp. 93048-93055 ◽  
Author(s):  
R. Giovannetti ◽  
E. Rommozzi ◽  
M. Zannotti ◽  
C. A. D'Amato ◽  
S. Ferraro ◽  
...  

Graphene dispersion (GR) was prepared by liquid-phase sonication of graphite and evaluated by XRD, DLS and UV-Vis analysis. It was used to prepare PP@mgGR–TiO2, showing positive effects on ARS photodegradation under visible light irradiation.


2011 ◽  
Vol 194-196 ◽  
pp. 385-388
Author(s):  
Hong Juan Wang ◽  
Feng Qiang Sun ◽  
Ming Zhong Ren ◽  
Qing Wei Guo

Nanoporous SnO2with high photocatalytic activity has been successfully prepared by a photochemical method, using SnCl2aqueous solution as a precursor. The as-synthesized sample was characterized by XRD, N2 adsorption-desorption and UV-vis. The photocatalytic activity of the sample was evaluated by degrading methylene blue (MB) aqueous solution under the UV light source and was compared with that of the commercial titania (Degussa P25). The results showed that the produced SnO2can degrade MB solution quickly and has comparative photocatalytic performance with P25 for degrading MB. This facile method supplies an effective way to prepare SnO2photocatalyst.


Sign in / Sign up

Export Citation Format

Share Document