Preparation and photocatalytic activity of CoFe2O4 nanoparticle modified rod-like Mn0.3Cd0.7S photocatalysts with S-scheme heterojunction

Abstract

With the continuous progress of photocatalytic technology in environmental pollution control, the recovery of photocatalysts has gradually become a hot topic of concern. To solve this problem, a magnetically recoverable rod-shaped CoFe2O4/Mn0.3Cd0.7S with S-scheme heterojunction photocatalyst was successfully constructed. The phase composition, morphology, light absorption, and surface chemical environment of the samples were measured. The photocatalytic degradation rate of tetracycline by CoFe2O4/Mn0.3Cd0.7S is higher than that either of CoFe2O4 and Mn0.3Cd0.7S. The degradation efficiency of 1%CoFe2O4/Mn0.3Cd0.7S showed the best performance of 82.1% within 60 min. The rate constant for first-order kinetics of 1%CoFe2O4/Mn0.3Cd0.7S was about 1.72 times that of pure Mn0.3Cd0.7S. It was found that the enhanced photoactivity of the CoFe2O4/Mn0.3Cd0.7S heterojunction photocatalyst was due to the wider absorption range of visible light and the improved inhibition of electron and hole recombination. It is also found that the CoFe2O4/Mn0.3Cd0.7S heterojunction photocatalyst has excellent magnetic recovery ability under the external magnetic field. The photostability of as-prepared CoFe2O4/Mn0.3Cd0.7S heterojunction photocatalyst was studied, and a reasonable S-scheme electron-hole transfer mechanism was proposed according to the band structure. These advances provide a new way to improve the photoactivity of magnetic recyclable photocatalysts, and the synthetic magnetic recyclable rod CoFe2O4/Mn0.3Cd0.7S has a potential application prospect in the degradation of water pollutants.