LAUSR

Aurivillius phases with narrow band gaps have attracted extensive interest in the field of photocatalysis, however, they exhibit poor activity due to the low utilization of photogenerated carriers. Herein, a series of S-scheme C3N4@Bi_m+1Fe_m-3Ti_3O_3m+3 (m = 4, 5, 6) heterojunctions with two-dimensional structures were synthesized by simple two-step method. Compared with single materials, the composites exhibit excellent photocatalytic tetracycline degradation under visible light, and 91.8% of tetracycline can be degraded accompanied with 81.2% of TOC removal within 120 min over C_3N_4@Bi_5FeTi_3O_15. The enhanced photocatalytic performance is due to strong interface interaction, high conductivity, and efficient charge separation ability. The mechanism analysis indicates that the C_3N_4@Bi_5FeTi_3O_15 heterojunction follows an S-scheme heterojunction mechanism with a strong interfacial internal electric field directed from C_3N_4 to Bi_5FeTi_3O_15, thus, the photogenerated electrons in Bi_5FeTi_3O_15 move toward C_3N_4, which retains high oxidation ability of Bi_5FeTi_3O_15 and high reduction ability of C_3N_4 to efficiently produce the reactive species, such as O_2^−· and ·OH. Graphical Abstract