“…5,[11][12][13][14] However, the pristine bulk g-C 3 N 4 exhibited low photocatalytic efficiency because of its low surface area and high recombination rate of charge carriers. Several effective approaches have been developed to promote the photoactivity of g-C 3 N 4 , including 15 nanostructure engineering (nanoparticles, nanowires, nanobelts, nanosheets, hollow vessels, etc. ), [15][16][17][18][19] doping with nonmetallic elements (B, F, P, and S), 20-23 deposition with metal atoms (Pd, Pt, Fe, and Au), [24][25][26][27] coupling with inorganic semiconductors (ZnO, NiS, ZnWO 4 , TaON, Bi 2 WO 6 ,WO 3 , MoS 2 , Bi 2 O 2 CO 3 , 20 BiOBr, and BiOI), 28-38 and construction of metal-free heterojunctions.…”