Efficient photocatalytic performance of direct Z-scheme photocatalyst Bi3TaO7/Mn0.5Cd0.5S for levofloxacin degradation under visible light irradiation.

The direct Z-scheme Bi 3 TaO 7 /Mn 0.5 Cd 0.5 S (MCS) composite photocatalyst was successfully constructed by an in-situ growth method. The performance for levofloxacin degradation by the composite catalysts under visible light irradiation was studied. The k value of BMCS-3 is the highest (0.05813 min⁻¹), which is 3.1 times larger than that of BTO (0.01846 min⁻¹) and 7.0 times larger than that of pure MCS (0.00825 min⁻¹). The photocurrent (PC), photoluminescence (PL) spectroscopy and electrochemical impedance spectroscopy (EIS) suggested that the migration rate of photogenerated electrons and holes were greatly improved after the combination of Bi 3 TaO 7 and Mn 0.5 Cd 0.5 S. On one hand, the separation efficiency of photogenerated electron-hole pairs of the composite material was improved due to the formation of Z-scheme heterojunction. On the other hand, the redox ability of photogenerated electron-hole pairs was maintained, which helped the composite material to exhibit enhanced photocatalytic performance. Meanwhile, the possible pathways of levofloxacin degradation and the toxicity of the produced intermediates were investigated. [Display omitted] • Novel Z-scheme Bi 3 TaO 7 /Mn 0.5 Cd 0.5 S composite photocatalysts were synthesized. • The photocatalyst exhibited high performance for the degradation of levofloxacin. • The rate constant improved by a factor of 3.1 and 7.0 compared to Bi 3 TaO 7 and Mn 0.5 Cd 0.5 S. • The mechanism on the enhanced performance was discussed deeply. • The deductive degradation pathway of levofloxacin was also proposed. [ABSTRACT FROM AUTHOR]