Formation of TiO2 nanostructure by plasma electrolytic oxidation for Cr(VI) reduction

2nd Colombian Congress of Electrochemistry; 2nd Symposium on Nanoscience and Nanotechnology

物理学;化学

Torres, D.A.^1 ; Gordillo-Delgado, F.^1 ; Plazas-Saldaña, J.^1

Universidad Del Quindío Armenia, Colombia^1

关键词: Colorimetric methods;    Diffractograms;    Hexavalent chromium;    Photocatalytic activities;    Plasma electrolytic oxidation;    Sample surface;    Switching power supplies;    Weight percentages;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/786/1/012046/pdf
DOI  :  10.1088/1742-6596/786/1/012046

来源: IOP

【 摘 要 】

Plasma electrolytic oxidation (PEO) is an environmentally friendly technique that allows the growth of ceramic coatings without organic solvents and non-toxic residues. This method was applied to ASME SB-265 titanium (Ti) plates (220.1cm) using voltage pulses from a switching power supply (340V) for 10 minutes at frequency of 1000Hz changing duty cycle at 10, 60 and 90% and the electrolytes were Na3PO4and NaOH. The treated sheets surfaces were analysed by X-ray diffraction and scanning electron microscopy. According to the diffractograms, the duty cycle increase produces amorphous TiO2coating on Ti sheets and the thickness increases. After sintering at 900°C during 1 hour, the 10% duty cycle generated a combination of anatase and rutile phases at the sample surface with weight percentages of 13.3 and 86.6% and particle sizes of 32.461±0.009nm and 141.14±0.03 nm, respectively. With this sample, the total reduction of hexavalent chromium was reached at 50 minutes for 1ppm solution. This photocatalytic activity was measured following the colorimetric method ASTM-3500-Cr B.