“…Among various metal oxide, titanium dioxide (TiO 2 ) has been found to be able to decompose different kinds of organic and inorganic waste in gas and liquid phases, and it becomes one of the most popular photocatalysis because of its chemically and biologically inert, photocatalytically stable, commercially available, inexpensive and from environmental viewpoint is friendly [4][5][6][7]. A number of commonly surface techniques have been developed to synthesize titanium dioxide, such as sol-gel [8][9][10][11][12][13], physical vapor deposition [14][15][16][17], chemical vapor deposition [18,19], laser nitriding [20][21][22], hydrothermal process [23], spray pyrolysis [24,25], liquid phase deposition [26] and anodizing. Among them, micro-arc oxidation (MAO) is one of the most promising and environmentally friendly technology by spark micro-discharges which move rapidly on the vicinity of the anode surface [27][28][29][30].…”