Rational design of a novel LaFeO3/g-C3N4/BiFeO3 double Z-scheme structure: Photocatalytic performance for antibiotic degradation and mechanistic insight

Abstract

A novel ternary symmetric double Z-scheme LaFeO3/g-C3N4/BiFeO3 (LCB) heterojunction nanocomposite was rationally obtained using a wet chemical process. The ternary system was confirmed by structural analysis and surface and morphological studies. This double Z-scheme photocatalyst showed an outstanding photocatalytic performance for ciprofloxacin (CIP) degradation compared to g-C3N4, LaFeO3, BiFeO3, and their binary nanocomposites. The enhanced photocatalytic activities were primarily derived from the improved light absorption capability, effective spatial separation, and prolonged charge carriers lifetime in the double Z-scheme system. In particular, the scavenger tests and electron spin resonance spectra demonstrated that •O2− and •OH are the primary oxidative radical species in the photocatalytic systems and confirmed the formation of the double Z-scheme structure. The possible degradation pathways of CIP were proposed based on ultra-performance liquid chromatography tandem-mass spectrometry analysis. This study may open a new insight into the design and synthesis of highly efficient double Z-scheme photocatalyst for environmental decontamination.