A visible-light sensitive MoSSe nanohybrid for the photocatalyticdegradationof tetracycline, oxytetracycline, and chlortetracycline.

A MoSSe nanohybrids (NHs) was synthesized, characterized, and tested for the degradation of tetracycline, oxytetracycline, and chlortetracycline under visible light irradiation. The Z-scheme MoSSe NHs exhibited higher specific surface area (∼10 times), faster charge separation, and greater photo-absorption than MoS2 nanoparticles (NPs) or MoSe2 NPs catalyst. The photocatalysts were characterized by ultraviolet-visible spectroscopy, X-ray diffraction, scanning electron microscopy, elemental mapping, transmission electron microscope, thermo-gravimetric analysis, X-ray photoelectron spectroscopy, photoluminescence, and electrochemical measurements. The MoSSe NHs exhibited significantly marked photocatalytic activity, achieving 95% of tetracycline (TC) degradation in 60 min with a rate constant of 0.1 min-1, which was about 5- and ∼ 6- fold that of MoS2 NPs and MoSe2 NPs, respectively. Superoxide radical (̇O2-) played the major role in catalytic reactivity. The mechanism and pathway of TC degradation on the Z-scheme nanohybrid photocatalyst was established. Moreover, the nanohybrid photocatalyst exhibited high structural stability, visible light absorption, and reusability in the removal of recalcitrant contaminants, namely, tetracycline, oxytetracycline, and chlortetracycline.