Synthesis of novel g-C3N4/KBiFe2O5 composite with enhanced photocatalytic efficiency

Novel graphitic carbon nitride (g-C3N4)/potassium bismuth ferrite (KBiFe2O5) composite photocatalysts were synthesized using facile grinding and calcination method. X-ray diffraction, transmission electron microscopy, scanning electron microscopy and UV–visible diffuse reflectance spectroscopy analysis were carried out to investigate structural, morphological and optical properties of the prepared samples. The photocatalytic properties of the samples were studied by photocatalytic degradation of methylene blue under visible light irradiation. The composite showed enhanced photocatalytic efficiency compared to both pristine g-C3N4 and KBiFe2O5. Out of four composites with different weight percentages of KBiFe2O5, one with 30 wt% showed the maximum photocatalytic efficiency. Samples with a higher content of KBiFe2O5 showed decreased photocatalytic efficiency indicating 30 wt% as the optimum composition. The increase in the photocatalytic efficiency is mainly due to efficient charge separation of photo-generated electron–hole pairs in the composites. The possible mechanism for the photo-catalysis of g-C3N4/KBiFe2O5 composites was also proposed.