Gliding Arc Plasma Synthesis of Visible-Light Active C-Doped Titania Photocatalysts

Gliding arc plasma is explored to synthesize C-doped TiO2 photocatalysts via tuning the ratio of O-2 to titanium tetraisopropoxide (TTIP) for the first time. XRD and HRTEM characterizations confirm that the samples synthesized at O-2/TTIP >= 18 are highly crystalline. When the O-2/TTIP ratio ranges from 18 to 36, the as-synthesized samples with similar to 70% of the weight fraction of anatase, 40-50m(2) g(-1) of specific surface area and similar to 2.7 eV of band energy gap, do show a greatly enhanced visible-light absorption and high activity for methylene blue (MB) degradation under visible-light irradiation (lambda > 420 nm). The gray sample synthesized at O-2/TTIP = 27 has the largest relative content of Ti3+ and oxygen vacancy (square) (Ti3+/square/Ti = 0.7/0.35/1) and exhibits the highest visible-light activity.