Boosting the visible-light activity of ZrO2/g-C3N4 by controlling the crystal structure of ZrO2

ZrO2/g-C3N4 semiconductor photocatalytic materials were prepared by ultrasonic method. The effect of zirconia with different crystal structure on visible light photocatalytic activity of ZrO2/g-C3N4 composite was investigated. Loading monoclinic and tetragonal mixed crystals ZrO2 can improve the photocatalytic degradation efficiency of g-C3N4. The optimum composite with 15 wt% ZrO2/g-C3N4 showed the superior photocatalytic activity for degradation of RhB and PNP under visible-light irradiation, which are 2.5 and 2.8 times higher than pure g-C3N4 under same conditions. The main active species affecting photocatalytic degradation are holes (h(VB)(+)) and center dot O-2(-) by photocatalytic active species capture experiment, center dot OH is also partially involved in the photocatalytic degradation. The 15 wt% ZrO2/g-C3N4 has excellent catalytic performance and good stability in photocatalytic repeated experiments, and has a broad application prospect. Graphic abstract