Phase transformation synthesis of novel Ag2O/Ag2CO3/g-C3N4 composite with enhanced photocatalytic activity

• Ag2O/Ag2CO3/g-C3N4 was firstly prepared by a facile phase transformation route.
• Ag2O/Ag2CO3/g-C3N4 exhibited good activity in phenol photodegradation.
• Holes radicals were the main active species.

Ag2O/Ag2CO3/g-C3N4 composite has been prepared for the first time by a facile phase transformation method. XRD and TEM analysis demonstrated that Ag2O and Ag2CO3 particles were well distributed on the surface of g-C3N4, and Ag2O/Ag2CO3/g-C3N4 heterojunction was formed. Phenol photodegradation by Ag2O/Ag2CO3/g-C3N4 was 11.0 and 19.1 times faster than that of g-C3N4 under UV and visible light irradiation, respectively. The enhanced photocatalytic activity resulted from the high separation efficiency of photogenerated electrons and holes. Moreover, holes radicals were the main active species. This study provides an approach to fabricate other novel heterostructured catalysts via the phase transformation of thermally unstable materials.