Dual-path inscription of plasmonic nano-Ag moiré fringes

Construction of moiré surface patterns has attracted considerable attention due to the fascinating function of photoelectric manipulation. Holographic inscription offers superposition of two or more sinusoidal gratings to form moiré structures. However, the current material platforms primarily depend on a single process of photoinduced physical property change to build up multicomponent gratings. Herein, we demonstrate a strategy of bidirectional photochemical reaction on mesoporous TiO2 matrices to form plasmonic nano-Ag moiré fringes. This consists of a photoreduction grating from in situ growth of Ag nanoparticles (NPs) and a photooxidation grating utilizing the Schottky interface of Ag/TiO2. The pattern obtained under the superposition of double spatial frequencies exhibits non-equidistant moiré fringes. This Letter provides a pathway for implementing complex surface structures.