Layer-by-layer (LbL) self-assembly represents a simple, robust, efficient, and highly versatile method, which allows for controllable integration of a large variety of materials (e.g., polymers, metal oxides, colloidal NPs, and even biologically active compounds) into various multilayer systems with tunable structures, compositions, properties, and innovative functions. We aim to craft multilayered heterostructured photocatalysts or photoelectrodes and mediate the charge transfer characteristic by  nano-architecture engineering.