Electrochemically assisted deposition by local pH tuning: a versatile tool to generate ordered mesoporous silica thin films and layered double hydroxide materials

This review presents the interest of electrochemistry for the preparation of two families of porous materials (ordered mesoporous silica and layer\ed double hydroxide), generated as thin films on solid electrode surfaces via an electrochemically assisted local pH tuning. The deposition mechanism is dependent on the target material. The driving force to get the ordered mesoporous silica thin films is the combination of electrochemical interfacial surfactant templating to the electro-assisted sol-gel deposition, leading to the growth of vertically aligned mesopore channels of surfactant-templated silica. The mechanism involved in the generation of layered double hydroxide (LDH) thin films is the electrochemically induced precipitation of the material by the electrogenerated hydroxide anions, which can be also applied to the formation of LDH-based composites. After a presentation of the materials that can be synthesized by the electrochemical manipulation of localized pH at electrode/solution interfaces, their characterization and applications are also briefly discussed.