A novel strategy to construct a direct Z-Scheme Bi@Bi2O2CO3/g-C3N4 heterojunction catalyst via PDA electronic bridge

Abstract

A novel strategy was employed to construct Z-Scheme Bi@Bi2O2CO3/PDA/g-C3N4 (BPCN) heterojunction through polydopamine (PDA) modification of g-C3N4 followed by deposition of Bi2O2CO3 component to efficiently remove tetracycline (TC) from water, in which PDA served as the electron transfer bridge and reductant for Bi reduction. The surface plasma resonance (SPR) effect of Bi nanoparticles and conjugated π structure shared between PDA and g-C3N4 can delocalize π-π* electrons thus promote the transport of carriers synergistically. The 10% BPCN catalysts showed much higher photocatalytic activities than single Bi2O2CO3, g-C3N4, and dual PDA/g-C3N4. The phase structure, morphology features, optical absorption and photoelectrochemical properties of BPCN were investigated in depth. Furthermore, the possible TC degradation pathway has been established based on liquid chromatography-mass spectrometry (LC-MS) analysis, and the acute toxicity LD50 of rat, bioconcentration factor, developmental toxicity and mutagenicity of TC and its degraded intermediates were evaluated based on quantitative structure activity relationship (QSAR).