Fabrication of TiO2 film by mechanical coating technique and its photocatalytic activity

Yoshida²,

Itoi

et al. 2017

Self Cite

Abstract:We successfully applied mechanical coating technique to prepare Ti coatings on the substrates of steel balls and stainless steel balls. The prepared samples were analyzed by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The weight increase of the ball substrates and the average thickness of Ti coatings were also monitored. The results show that continuous Ti coatings were prepared at different revolution speeds after different durations. Higher revolution speed can accelerate the formation of continuous Ti coatings. Substrate hardness also markedly affected the formation of Ti coatings. Specifically, the substance with lower surface hardness was more suitable as the substrate on which to prepare Ti coatings. The substrate material plays a key role in the formation of Ti coatings. Specifically, Ti coatings formed more easily on metal/alloy balls than ceramic balls. The above conclusion can also be applied to other metal or alloy coatings on metal/alloy and ceramic substrates.

Section: Introductionmentioning

confidence: 99%

Preparation of Metal Coatings on Steel Balls Using Mechanical Coating Technique and Its Process Analysis

Yoshida²,

Itoi

et al. 2017

Self Cite

“…The M10-xCr samples show metallic color, which is same to that of Ti coatings [16]. In contrast, the M10-xCr-y K/z h samples appear various colors, which are brown to light-black at 973 K for 3 h, and light-blue to yellow at 1073 K for 3 h, then light-black to dark-blue at 973 K for 10 h, as shown in Figure 1.…”

Section: Appearance and Phase Evolution Of Photocatalyst Composite Comentioning

confidence: 70%

Fabrication of Photocatalyst Composite Coatings of Cr-TiO2 by Mechanical Coating Technique and Oxidation Process

Guan

et al. 2015

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Abstract:The photocatalyst composite coatings on alumina (Al2O3) balls had been prepared by mechanical coating technique (MCT) with titanium (Ti) powder, adding a certain content of chromium (Cr) powder and a subsequent oxidation process. The effect of oxidation conditions and adding Cr on the composite coatings of chromium-titanium dioxide (Cr-TiO2) was investigated. The results show Cr-TiO2 coatings are with mixed-phase of anatase and rutile under different oxidation conditions, and the mass fraction of the rutile phase (XR) has been obviously increased when under 973 K. The SEM images indicate that adding Cr could significantly accelerate the growth of surface structures, especially at 1073 K. The photocatalytic activity of Cr-TiO2 coatings firstly increases, then decreases, with the addition of Cr. Compared with that of two other oxidation conditions, the enhancement on photocatalytic activity by adding Cr under visible light is relatively higher, especially at 973 K for 10 h.

“…The M10-xCr coatings show a metallic color, which is the same as M10-Ti [8]. In contrast, Figure 48 shows the M10-xCr coatings after being oxidized at elevated temperatures for 15 h. The M10-xCr-yK samples display various colors, which are grey, brown, and light-brown at 873 K, blue and light-yellow at 973 K, and light-white and light-grey at 1073 K. With added Cr, the color of samples obviously changes at each temperature.…”

Section: Influence On Photocatalyst Coatings Of Tio2 By Adding Crmentioning

confidence: 90%

“…Focusing on Oxidation Temperature Figure 22 shows the appearance photograph of M10-xK-yh samples. The Ti coatings (M10-Ti) show metallic color [8]. In contrast, the M10-xK-yh samples appear to have various colors, under different oxidation conditions, as shown in Figure 22.…”

Section: Influence On Photocatalyst Coatings Of Tio2 By Oxidation Conmentioning

confidence: 98%

“…Their advantages and limitations are summarized in Table 1 [3]. In order to solve these problems, our group had proposed a novel coating fabrication technique to form the coating materials, named as mechanical coating technique (MCT), with the diagram schematic shown in Figure 1 [7,8]. The metal coatings on Al2O3 balls had been prepared by MCT, shown as Figure 2a, and the metal coatings could be treated by a thermal process, as shown in Figure 2b.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Review on the Photocatalyst Coatings of TiO2: Fabrication by Mechanical Coating Technique and Its Application

Guan

et al. 2015

Self Cite

This review presents the latest results of studies directed at photocatalyst coatings of titanium dioxide (TiO2) prepared by mechanical coating technique (MCT) and its application. Compared with traditional coating techniques, MCT is a simple, low cost and useful coating formation process, which is proposed and developed based on mechanical frictional wear and impacts between substrate materials and metal powder particles in the bowl of planetary ball mill. The formation process of the metal coatings in MCT includes four stages: The nucleation by adhesion, the formation and coalescence of discrete islands, formation and thickening of continuous coatings, exfoliation of continuous coatings. Further, two-step MCT was developed based on the MCT concept for preparing composite coatings on alumina (Al2O3) balls. This review also discusses the influence on the fabrication of photocatalyst coatings after MCT and improvement of its photocatalytic activity: oxidation conditions, coating materials, melt salt treatment. In this review, the oxidation conditions had been studied on the oxidation temperature of 573 K, 673 K, 773 K, 873 K, 973 K, 1173 K and 1273 K, the oxidation time of 0.5 h, 1 h, 3 h, 10 h, 15 h, 20 h, 30 h, 40 h, and 50 h. The photocatalyst coatings showed the highest photocatalytic activity with the oxidation condition of 1073 K for 15 h. The metal powder of Ti, Ni and Cr had been used as the coating materials. The composite metal powder could affect the surface structure and photocatalytic OPEN ACCESSCoatings 2015, 5 426 activity. On the other hand, the melt salt treatment with KNO3 is an effective method to form the nano-size structure and enhance photocatalytic activity, especially under visible light.