Accurate guided alternating atomic layer enhance internal electric field to steering photogenerated charge separation for enhance photocatalytic activity

Bi4O5BrxI2-xCy solid solutions with simultaneous bismuth-enriched and low temperature homogeneous C doping were obtained by the phase crystal reforming of BiOI with solvothermal alkali assisted molten salt method. The internal electric field between alternating atomic layers was significantly enhanced due to the synergism of formation of solid solutions, enrichment Bi and homogeneous C doping. Driven by the strong internal electric field, the photogenerated electrons and holes of Bi2.8C1.2O5Br0.5I1.5 were confined to the [Bi2.8C1.2O5]2+ layer and the double [Br0.5I1.5]− layer, respectively, then effective separation of charge carriers was achieved. The removal rates over Bi2.8C1.2O5Br0.5I1.5 of phenol, 4-chlorophenol, resorcinol and hydroquinone were 100 % in 1 h under visible light irradiation, which followed the parallel attack mechanism of O2- and h+. This study provided a reference for the multiple coordinated regulation of internal electric field by formation of solid solutions, enrichment Bi and homogeneous doping.