NiFe2O4/g-C3N4 heterojunction composite with enhanced visible-light photocatalytic activity

Spinel structure nickel ferrite (NiFe2O4) doped graphitic carbon nitride (g-C3N4) photocatalyst NiFe2O4/g-C3N4 was synthesized by the coprecipitation route to enhance the photocatalytic activity for the visible-light driven degradation of methyl orange. The NiFe2O4 doping content is responsible for the microstructure and photocatalytic activity of NiFe2O4/g-C3N4 samples. Compared with pure NiFe2O4 and g-C3N4, the 2-NiFe2O4/g-C3N4 composite with NiFe2O4 doping of 2.0 wt% exhibited excellent photocatalytic activity and superior stability after five runs for degrading methyl orange under visible light irradiation. The catalytic activity of 2-NiFe2O4/g-C3N4 sample produced using the coprecipitation route was higher than those of conventional 2-NiFe2O4/g-C3N4 bulks prepared by the impregnation approach. The prepared samples for the photocatalytic degradation of methyl orange followed pseudo-first-order reaction kinetics. It's ascribed to the synergistic effect between NiFe2O4 and g-C3N4, which can inhibit the recombination of photoexcited electron-hole pairs, accelerate photoproduced charges separation, and enhance the visible light absorption.