High‐performance photocatalyst containing noble metals selectively deposited inside mesopore

Abstract We describe a general photoelectrical deposition process for the priority deposition of noble metals inside surface mesopores, which are selectively formed in the interstitial regions between crystal arrays composed of sintered photoactive nanocrystals. The basis of our approach is to prepare continuous coherent bonds between photoactive nanocrystals aligned toward the surface accompanied by the formation of interstices (2–20 nm) filled with a heterogeneous insulator phase between the crystal arrays; the subsequent removal of part of the heterogeneous phase creates surface mesopores. The coherent crystalline structure causes a smooth electron flow from the outside to the inside of the array through the coherent boundaries of the nanocrystals during photodeposition using an ultraviolet lamp, accompanied by outside‐hole consumption and noble metal deposition in the recesses of the surface mesopores. The size and morphology of the deposited noble metals are restricted to the shape of the formed mesopores, which can be easily controlled. This approach is applicable to a wide range of functional materials and is expected to be applicable to the preparation of excellent photocatalysts, redox catalysts, and photochromic materials. Using our new process, we also achieved a remarkable increase in the photocatalytic activity of the obtained Pd‐deposited TiO ₂ /SiO ₂ photocatalytic fiber.