Magic-Sized Nanoclusters-Induced Cascade Tandem Charge Transfer for Solar Water Oxidation

Magic-sized nanoclusters (MSCs) have been attracting enduring interest by virtue of the quantum confinement effect, discrete energy band structure, and enriched catalytic active sites. Nevertheless, up to date, exploration of MSCs artificial photosystems and fine-tuning of spatial vectorial charge transfer in photoredox catalysis have so far been scarcely reported. Hence, we employed a facile and easily accessible layer-by-layer (LbL) assembly strategy to highly ordered, alternately, and periodically deposit oppositely charged tailor-made transition metal chalcogenides (TMCs) MSCs and non-conjugated polymer (NCP) building blocks on the MO substrate, resulting in the MO/(NCP-TMCs MSCs)_n multilayer heterostructures. It is affirmed that the ultra-thin NCP uniformly intercalated at the interface of every TMCs MSCs layer fosters the unidirectional electron flow from TMCs MSCs to MO substrate with the assistance of NCP, and moreover the multilayered interface configuration benefits the establishment of cascade tandem charge transfer route, synergistically giving rise to the significantly enhanced charge separation and boosted solar water oxidation performances of MO/(TMCs MSCs-NCP)_n heterostructure under simulated solar light irradiation. Our work elucidates the specific roles of NCP and MSCs as charge relay mediators and photosensitizers, affording a quintessential paradigm to rationally regulate the photocarrier transport and separation over MSCs for solar energy conversion.