ZnO　thin　films　in　nanorod　(NR)　and　nanoflower　(NF)　morphologies　were　used　as　photoelectrode　scaffolds　for　efficient　visible-light-driven　photoelectrochemical　(PEC)　water　splitting　process,　where　their　decoration　with　copper　indium　gallium　sulfide　(CIGS)　and　indium　sulfide　(In2S3)　layers　resulted　in　significant　PEC　performance　enhancement.　ZnO　NF/CIGS/In2S3　photoelectrodes　exhibited　a　remarkably　high　PEC　efficiency　(∼6.0%　applied　bias　photon-to-current　efficiency,　83%　incident　photon-to-current　efficiency)　due　to　the　negligible　dark　current,　while　ZnO　NR/CIGS/In2S3　generated　a　photocurrent　density　of　30.0mA.cm-2　at　0.4　V　(vs　Ag/AgCl),　being　one　of　the　highest　performances　reported　in　the　literature　for　copper-based　chalcopyrite　photoelectrodes　so　far.　The　interfacial　photoelectrode-electrolyte　charge　transport　dynamics,　investigated　via　intensity-modulated　photocurrent　spectroscopy,　exhibited　a　sevenfold　increase　in　charge　transfer　efficiencies　with　a　significant　drop　in　surface　recombination　kinetics　for　ZnO　NF　after　CIGS/In2S3　decoration.　The　obtained　results　show　consistency　with　numerically　modeled　electric　field　distribution　profiles　and　electron　paramagnetic　resonance　results　of　ZnO　NF,　rationalizing　the　enhanced　charge　transfer　rates　for　decorated　samples　and　confirming　the　defect　passivating　nature　of　CIGS/In2S3.　©　2021　American　Physical　Society.