In situ fabrication of In_2.77S₄/In-MOFs Z-scheme heterojunction composites with enhanced visible light photocatalytic activity for degradation of tetracycline

The In_2.77S₄/In-MOFs Z-scheme heterojunction composite photocatalysts were successfully synthesized via an insitu hydrothermal growth method. The chemical structure, morphology, optical properties, and photogenerated carriers transfer behavior of the as-prepared In_2.77S₄/In-MOFs composites were characterized in details. The In_2.77S₄/In-MOFs (10 wt%) composite showed the optimal photocatalytic degradation efficiency of 95.9% in 90 min for the tetracycline (TC) model pollutant, which was significantly higher than that of pure In_2.77S₄ (75.1%) and In-MOFs (9.7%). The X-ray photoelectron spectrometer (XPS), photoelectrochemical, and electron paramagnetic resonance (EPR) technique were carried out to illuminate the photocatalytic degradation mechanism of In_2.77S₄/In-MOFs (10 wt%) for TC, which showed that the Z-scheme heterojunction structure of In_2.77S₄/In-MOFs (10 wt%) could reinforced the light harvesting capacity and promote the photogenerated carrier migration under visible light irradiation. Furthermore, the photogenerated holes play a major role during the photocatalytic degradation reaction. Finally, this work maybe offers an effective method for the designing In_2.77S₄-based Z-scheme heterojunctions to facilitate the charge carrier transfer in heterogeneous catalysts.