Degradation of pollutants by Bi-doped LaFeO3/CQDs/CN Z-scheme heterojunction photocatalysts and mechanism study

Abstract

In this paper, Z -scheme heterojunction Bi-doped LaFeO 3 /CQDs/CN (LBFO/CQDs/CN) photocatalysts were successfully synthesized. Compared to CN, LFO, LBFO, and their two-component composites, LBFO/CQDs/CN exhibits better degradation performance of pollutants such as RhB, TCL, MB, and MO. The main reason is that Bi doping could facilitate the extended absorption of visible light and the promotion of oxygen vacancies by LFO. On the other hand, CQDs, as a medium for electron migration between CN and LBFO, effectively enhance the efficiency of electron migration in Z -scheme heterojunctions and achieve spatial separation of electrons and holes. The successful preparation of the three-component material and its good performance was confirmed by various characterization methods. In addition, capture experiments demonstrate that superoxide radicals (·O 2 − ) are the main active species in the reaction, while the formation of Z -scheme heterojunctions is demonstrated using a carrier migration mechanism. • A novel Z -scheme photocatalyst Bi-doped LaFeO 3 /CQDs/CN was synthesized. • Bi 3+ doping facilitated the formation of oxygen vacancies. • CQDs acted as intermediaries and enhanced charge transfer. • It exhibited excellent photocatalytic activity and cyclic stability.