Preparation and photocatalytic performance study of dual Z-scheme Bi2Zr2O7/g-C3N4/Ag3PO4 for removal of antibiotics by visible-light

At present,the high re-combination rate of photogenerated carriers and the low redox capability of the photocatalyst are two factors that severely limit the improvement of photocatalytic performance.Herein,a dual Z-scheme photocatalyst bismuthzirconate/graphitic carbon nitride/silver phosphate (Bi2Zr2O7/g-C3N4/Ag3PO4(BCA)) was synthesized using a co-precipitation method,and a dual Z-scheme heterojunction photocatalytic system was established to decrease the high re-combination rate of photogenerated carriers and consequently improve the photocatalytic performance.The re-combination of electron-hole pairs(e-and h+) in the valence band (VB) of g-C3N4increases the redox potential of e-and h+,leading to significant improvements in the redox capability of the photocatalyst and the efficiency of e--h+separation.As a photosensitizer,Ag3PO4can enhance the visible light absorption capacity of the photocatalyst.The prepared photocatalyst showed strong stability,which was attributed to the efficient suppression of photo-corrosion of Ag3PO4by transferring the e-to the VB of g-C3N4.Tetracycline was degraded efficiently by BCA-10%(the BCA with 10 wt.%of AgPO4) under visible light,and the degradation efficiency was up to 86.2%.This study experimentally suggested that the BCA photocatalyst has broad application prospects in removing antibiotic pollution.