Hierarchically Z-scheme photocatalyst of {0 1 0}BiVO4/Ag/CdS with enhanced performance in synergistic adsorption-photodegradation of fluoroquinolones in water

In this work, the sheet-like BiVO 4 with a higher exposure ratio of {0   1   0} facets was synthesized by the addition of TiCl 3 , and the ratio of (0   4   0)/(0   1   1) on {0   1   0}BiVO 4 was 2.85 times higher than that of normal decahedral BiVO 4 . Accordingly, the {0   1   0}BiVO 4 /Ag/CdS all-solid-state Z-scheme heterojunction was further constructed by photoreduction of Ag and chemical deposition of CdS on the well prepared {0   1   0}BiVO 4 successively. The performance and mechanism of {0   1   0}BiVO 4 /Ag/CdS in synergistic adsorption-photodegradation of fluoroquinolones (FQs) from water were investigated in detail. The adsorption-photodegradation could be divided into three processes: adsorption, surface degradation, and solution degradation, with the rate constants of 0.118, 0.029, and 0.012 min −1 , respectively. Accordingly, the adsorption was a rapid process due to the combined CdS in this composited photocatalyst had a high affinity to FQs to achieve an adsorption equilibrium on the surfaces<30.0 min. Besides, {0   1   0}BiVO 4 /Ag/CdS had a better separation efficiency of photogenerated electron-hole pairs than BiVO 4 /Ag/CdS, because the enriched {0   1   0} facets of {0   1   0}BiVO 4 caused more BiVO 4 /Ag/CdS ternary structure formed, and>90% photodegradation efficiency for five FQs ( C 0  = 0.062 mmol/L) was thus obtained within 60.0 min. The radical trapping and EPR results showed that holes and superoxide radicals were the main active species for FQs photodegradation. In summary, {0   1   0}BiVO4/Ag/CdS achieved an enhanced performance in synergistic adsorption and photodegradation of organic contaminants from water, and a talented photocatalyst was thus provided in water and wastewater treatment.