“…6,7 Fabrication of heterojunctions has been proved an effective way to enhance the charge separation efficiency of g-C 3 N 4 -based photocatalysts. 8,9 Numerous semiconductors have been investigated to form heterojunctions with g-C 3 N 4 , such as metal oxides (e.g., ZnO, TiO 2 and Cu 2 O), 10,11 metal sulfides (e.g., NiS and CdS), 12,13 metal oxyhalides (e.g., BiOCl and BiOBr) 14,15 and other semiconductors (e.g., perovskites and layered double hydroxides). 16,17 Based on the charge separation mechanism, these heterojunctions can be generally classified into two types: a type II heterostructure and an all-solid-state Z-scheme heterostructure.…”