Vertical interface coupling between crystalline α-Fe2O3 and carbon nitride nanosheets for efficient degradation of organic pollutants

•Crystal engineering was beneficial to regulate the charge on the crystal surface.•The α-Fe2O3 and ACN with different coupling facets were constructed.•The Fe001/ACN and Fe110/ACN+ nanosheets were successfully prepared.•The O2– and h+ played decisive roles in photocatalytic degradation.•The intermediates of OTC reaction were identified by high resolution LC-MS.