In-situ fabrication of Bi2S3/BiVO4/Mn0.5Cd0.5S-DETA ternary S-scheme heterostructure with effective interface charge separation and CO2 reduction performance

•Bi2S3/BiVO4/Mn0.5Cd0.5S-DETA ternary heterostructure is obtained.•The heterostructure exhibited excellent photocatalytic CO2 reduction and stability.•Mechanism of charge transfer and separation in S-scheme heterojunction is proposed.•S-scheme photocatalytic mechanism is discussed.