Fabrication of novel Z-scheme LaCoO3/activated biochar/Ag3PO4 heterojunctions for intensifying visible-light-catalytic degradation of bisphenol A

Abstract

A novel Z-scheme LaCoO3/activated biochar(AC)/Ag3PO4 heterojunctions was fabricated and characterized by XRD, SEM-EDS, TEM, XPS, FTIR, N2 adsorption–desorption isotherms, UV–Vis-DRS, PL and EIS. The catalytic activity of the photocatalyst was investigated via bisphenol A (BPA) photocatalitic degradation. The results showed that the photodegradation efficiencies of BPA catalyzed by LaCoO3/AC/Ag3PO4 (2:1:10) composite (reached 99 % after 50 min) was superior to those catalyzed by LaCoO3, Ag3PO4, and LaCoO3/Ag3PO4 (2:10). The BPA photodegradation followed the pseudo-first-order kinetic model, the photodegradation rate constants k catalyzed by LaCoO3/AC/Ag3PO4 (2:1:10) was 10.88 times of that catalyzed by Ag3PO4, 1.56 times of that catalyzed by LaCoO3/Ag3PO4 (2:10). Based on the results of characterization and the experiments of trapping active species in photocatalytic degradation process, the transfer of photo-generated carriers and Z-scheme LaCoO3/AC/Ag3PO4 heterojunctions photocatalytic mechanism were proposed. Furthermore, the possible BPA degradation pathways were involved in hydroxylation, oxidation, ketonization and cyclic cleavage. Z-scheme LaCoO3/AC/Ag3PO4 heterojunctions can be used as an efficient photocatalyst for practical applications in the removal of endocrine disrupting chemical.