Precision engineering of Z-scheme interfacial charge transfer in Bi2WO6/CoPc through W-based bonds and internal electric field for efficient CO2 photoreduction

•CoPc/Bi2WO6 heterojunction with Co2+ centres have been effectively fabricated.•The built-in electric field and covalent bonding cause effective Z-scheme system.•The Co2+ centres could capture photoelectrons and encourage the CO2 activation.•Optimized CoPc/Bi2WO6 heterojunction shows superior photocatalytic activities for CO2 reduction.