Embedding ZnCdS@ZnIn2S4 into thiazole-modified g-C3N4 by electrostatic self-assembly to build dual Z-scheme heterojunction with spatially separated active centers for photocatalytic H2 evolution and ofloxacin degradation

•The dual Z-scheme heterojunction improves the separation and migration efficiency of electron-hole pairs.•The space separation between the oxidation center and the reduction center improves the utilization rate of carriers.•Thiazoles as an electron acceptor to reconstruct electrons on the g-C3N4 surface and adjust its HOMO and LUMO dispersion to improve electron mobility.•ZnCdS@ZnIn2S4@g-C3N4-vTA prepared by electrostatic self-assembly, and its intimate interfacial contact shortens the migration distance of carriers.