Photocatalytic degradation of organophosphate flame retardant TBEP: kinetics and identification of transformation products by orbitrap mass spectrometry

Abstract

ABSTRACTThe photocatalytic degradation of tris (2–butoxyethyl) phosphate (TBEP) flame retardant using visible light response catalysts TiO2/V2O5, (N,F-doped)-TiO2/V2O5, and N-doped-SrTiO3 has been studied by high-resolution orbitrap mass spectrometry. TBEP degradation followed first-order kinetics with half-life values ranging between 9.8 and 83.5 min. N-doped-SrTiO3 was the catalyst with better photocatalytic performance while activity for TiO2/V2O5 composites followed the trend: N, F- TiO2/V2O5 > N-TiO2/V2O5> TiO2/V2O5. The identified degradation products (DPs) revealed hydroxylation, further oxidation and dealkylation as major degradation pathways. Based on the identified DPs and scavenging experiments, •OH radical-mediated reactions can be considered for the degradation of TBEP using TiO2 and SrTiO3-based photocatalytic materials.