Preparation of a novel bimetallic AuCu-P25-rGO ternary nanocomposite with enhanced photocatalytic degradation performance

•A novel bimetallic AuCu-P25-rGO ternary nanocomposite was successfully prepared.•The photocatalyst could efficiently photodegrade 2-nitrophenol, MB and RhB.•The photocatalyst with Au/Cu ratio=1:1 showed higher activity than 1:3 and 3:1.•The proposed photocatalytic mechanism of this photocatalyst was inferred.•The ternary nanocomposite could suppress recombination of photogenerated carriers.