Influence of carbon atmosphere on surface morphology and photocatalytic activity of TiO2 coatings by multi-heat treatment

2015 ◽  
Vol 27 (4) ◽  
pp. 3873-3879 ◽  
Author(s):  
Sujun Guan ◽  
Liang Hao ◽  
Hiroyuki Yoshida ◽  
Hiroshi Asanuma ◽  
Fusheng Pan ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Photocatalytic Activity ◽  
Surface Morphology ◽  
Tio2 Coatings

Enhanced Photocatalytic Activity of TiO2 Coatings by Heat Treatment in Carbon Powder

2015 ◽  
Author(s):  
Sujun Guan ◽  
Liang Hao ◽  
Kohei Miyazawa ◽  
Yun Lu ◽  
Hiroyuki Yoshida ◽  
...  
Keyword(s):  
Thin Films ◽  
Heat Treatment ◽  
Photocatalytic Activity ◽  
Band Gap ◽  
Carbon Powder ◽  
Fiber Morphology ◽  
Rutile Tio2 ◽  
Micro Cracks ◽  
Nano Fiber ◽  
Tio2 Coatings

The heat treatment in carbon powder is a safe and effective strategy to enhance the photocatalytic activity of titanium dioxide (TiO2) coatings. Firstly, Ti coatings were prepared by mechanical coating operation with Ti powder on alumina balls. Secondly, the target TiO2 coatings were prepared using the prepared Ti coatings by the multi-heat treatment (pretreatment in carbon powder, oxidation in air and reduction in carbon powder). During the pretreatment, thin films of Ti2CO and micro-cracks form in the surface of the Ti coatings. The formed thin films and micro-cracks are helpful for forming a nano-fiber morphology of rutile TiO2, during the subsequent oxidation. During the reduction, oxygen vacancies generated in the lattice of rutile TiO2 are in favor of narrowing the band gap. The target TiO2 coatings with a nano-fiber morphology and the narrowed band gap, effectively enhances the photocatalytic activity by more than 3 times, compared with the pristine TiO2 coatings.

Effects of Heat Treatment Temperature on Photocatalytic Activity of TiO2/SiO2 Composite Aerogels

2013 ◽  
Vol 27 (10) ◽  
pp. 1079-1083
Author(s):  
Zhao-Hui LIU ◽  
Gen-Liang HOU ◽  
Xun-Jia SU ◽  
Feng GUO ◽  
Zhou XIAO ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Photocatalytic Activity ◽  
Heat Treatment Temperature ◽  
Treatment Temperature ◽  
Composite Aerogels

scholarly journals Failure Analysis of Rheocast Cylinder Head Covers of Hypereutectic Al–Si Alloys

2020 ◽  
Author(s):  
Jian Feng
Keyword(s):  
Heat Treatment ◽  
Surface Morphology ◽  
Service Time ◽  
Shot Peening ◽  
High Frequency ◽  
Cylinder Head ◽  
Die Casting ◽  
Fatigue Properties ◽  
Homogeneous Distribution ◽  
Engine Components

AbstractThe purpose of the present study is to determine the cause of failures of semisolid rheocast cylinder head covers of hypereutectic modified LM30 alloys. The covers, manufactured by rheocasting, a process that consists of the incorporation and homogeneous distribution of the reinforcements in semisolid metal (SSM) before die casting, were shot-peened after heat treatment to increase the fatigue resistance. However, these engine components failed during operation after a short service time. The major flaws were located by radiography. The microstructure was controlled by metallography. Significant interactions between shot peening and surface/subsurface contaminants were identified by surface morphology and fractography. The fatigue properties of hypereutectic alloys were investigated by a high-frequency vibrophore. It was identified that the failure was related to the cleanliness of SSM as well as the rheocasting process. Recommendations were given to prevent the recurrence of similar failures.

Effect of heat treatment on the photocatalytic activity of α-Fe2O3 nanoparticles: towards diclofenac elimination

2021 ◽  
Author(s):  
Ibtihal Mimouni ◽  
Asmae Bouziani ◽  
Yassine Naciri ◽  
Mourad Boujnah ◽  
Mohammed Alaoui El Belghiti ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Photocatalytic Activity ◽  
Fe2o3 Nanoparticles

scholarly journals Structure, tribological behaviour and photocatalytic activity of ARC-PVD TiO2 coatings obtained with a modified curvilinear magnetic filter

2019 ◽  
Vol 15 (2) ◽  
pp. 121-130
Author(s):  
A.V. Taran ◽  
I.E. Garkusha ◽  
V.S Taran ◽  
A.I. Timoshenko ◽  
I.A Misiruk ◽  
...  
Keyword(s):  
Photocatalytic Activity ◽  
Tribological Behaviour ◽  
Magnetic Filter ◽  
Tio2 Coatings

scholarly journals Effect of pH on the characteristics of electroless Ni-P coatings

2017 ◽  
Vol 53 (3) ◽  
pp. 327-332 ◽  
Author(s):  
M. Czagany ◽  
P. Baumli
Keyword(s):  
Heat Treatment ◽  
Surface Morphology ◽  
Coating Thickness ◽  
Phase Structure ◽  
Phosphorus Content ◽  
Effect Of Ph ◽  
Alkaline Bath ◽  
Steel Substrates ◽  
Electroless Ni ◽  
Thick Coatings

In this study electroless Ni-P coatings were deposited on W302 steel substrates. The effects of bath pH and heat treatment at 400?C were investigated on the surface morphology, phase structure, phosphorus content, thickness and microhardness of the coatings. It was observed that both the phosphorus content and coating thickness are dependent on the bath pH. In an acidic/neutral bath, low and medium phosphorus coatings with thickness of 13.9-19.8 ?m were synthesized, while in an alkaline bath, high phosphorus, 4.8-5.8 ?m-thick coatings were formed. Coatings containing medium or high P seemed to be amorphous, while low P coatings had microcrystalline structures. Hardness was also dependent on the composition of the coating. After heat treatment, the structure of the coatings transformed into crystalline Ni with the precipitation of Ni3P phases, which resulted further increases in hardness.

scholarly journals Biosorption of Lanthanides from Aqueous Solutions Using PretreatedBuccinum tenuissimumShell Biomass

2010 ◽  
Vol 2010 ◽  
pp. 1-10 ◽  
Author(s):  
Yusuke Koto ◽  
Naoki Kano ◽  
Yudan Wang ◽  
Nobuo Sakamoto ◽  
Hiroshi Imaizumi
Keyword(s):  
Crystal Structure ◽  
Heat Treatment ◽  
Rare Earth ◽  
Surface Morphology ◽  
Aqueous Solutions ◽  
Specific Surface ◽  
Calcium Oxide ◽  
Original Sample ◽  
Freundlich Isotherms ◽  
Langmuir And Freundlich Isotherms

Biosorption experiment from aqueous solutions containing known amount of rare earth elements (REEs) using pre-treatedBuccinum tenuissimumshell was explored to evaluate the efficiency of shell biomass as sorbent for REEs. In this work, four kinds of sieved shell samples: (a) “Ground original sample”, (b) “Heat-treatment (480∘C, 6 hours) sample”, (c) “Heat-treatment (950∘C, 6 hours) sample” and (d) “Heat-treatment (950∘C, 6 hours) and water added sample” were used. Furthermore, to confirm the characteristics of the shell biomass, the crystal structure, the surface morphology, and the specific surface area of these shell samples were determined. Consequently, the following matters have been mainly clarified. (1) The crystal structure of the shell biomass was transformed from aragonite (CaCO3) into calcite (CaCO3) phase by heat-treatment (480∘C, 6 hours); then mainly transformed into calcium oxide (CaO) by heat-treatment (950∘C, 6 hours), and calcium hydroxide(Ca(OH)2)by heat-treatment (950∘C, 6 hours) and adding water. (2) The shell biomass showed excellent sorption capacity for lanthanides. (3) Adsorption isotherms using the shell biomass can be described by Langmuir and Freundlich isotherms satisfactorily for lanthanides except “heat-treatment (950∘C, 6 hours) sample”. (4) Shell biomass (usually treated as waste material) can be an efficient sorbent for lanthanides in future.

scholarly journals Enhanced visible-light photocatalytic activity of anatase-rutile mixed-phase nano-size powder given by high-temperature heat treatment

2020 ◽  
Vol 7 (1) ◽  
pp. 191539 ◽  
Author(s):  
Takamasa Ishigaki ◽  
Yusuke Nakada ◽  
Naoki Tarutani ◽  
Tetsuo Uchikoshi ◽  
Yoshihiro Tsujimoto ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Photocatalytic Activity ◽  
High Temperature ◽  
Visible Light ◽  
Photocatalytic Performance ◽  
High Temperature Heat Treatment ◽  
Heat Treated ◽  
Temperature Heating ◽  
Nano Size ◽  
Visible Light Photocatalytic

Nano-size EVONIK AEROXIDE ® P25 titanium dioxide, TiO 2 , powder was heat-treated at temperatures, 700–900°C, in air. An X-ray diffraction study showed that the P25 powder is composed of approximately 20 and approximately 80 mass% of rutile and anatase phases, respectively. It was also shown that the transformation from anatase to rutile induced by high-temperature heat treatment was almost completed at 750°C, whereas a small amount (less than 3 mass%) of anatase phase was still left even in the powder heat-treated at 900°C. The transformation behaviour was consistent with results obtained by Raman scattering spectroscopy. Raman experiments also indicated that high-temperature heating induced the formation of oxide ion vacancies. Powders were dispersed in methyl orange (MO) aqueous solution, and the bleach rate of MO was measured to evaluate photocatalytic activity under ultraviolet (UV)- and visible-light irradiation. After the heat treatment, the UV-light photocatalytic performance sharply deteriorated. Interestingly, visible-light photocatalytic activity was enhanced by high-temperature heating and reached the highest performance for an 800°C-heated sample, indicating that the P25 powder obtained high visible-light photocatalytic performance after heat treatment. Even after 900°C heat treatment, the photocatalytic performance was higher than that of as-received powder. Enhancement of photocatalytic activities was discussed in relation to visible light absorption and charge carrier transfer.

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