title: Towards visible light hydrogen generation: quantum dot-sensitization via efficient light harvesting of hybrid-TiO2.
abstract: We report pronounced enhancement of photoelectrochemical hydrogen generation of a quantum dot-sensitized hybrid-TiO2 (QD/H-TiO2) electrode that is composed of a mesoporous TiO2 layer sandwiched by a double sided energy harvesting layer consisting of a surface-textured TiO2 inverse opals layer on the bottom and a patterned mesoporous TiO2 layer on the top. CdSe/H-TiO2 exhibits a maximum photocurrent density of ~16.2 mA/cm(2), which is 35% higher than that of the optimized control sample (CdSe/P25), achieved by matching of the bandgap of quantum dot-sensitization with the wavelength where light harvesting of H-TiO2 is observed. Furthermore, CdSe/H-TiO2 under filtered exposure conditions recorded current density of ~14.2 mA/cm(2), the greatest value in the visible range. The excellent performance of the quantum dot-sensitized H-TiO2 suggests that alteration of the photoelectrodes to suitable nanostructures with excellent light absorption may offer optimal strategies for attaining maximum efficiency in a variety of photoconversion systems.
authors.affiliation: Interdisciplinary School of Green Energy and Low Dimensional Carbon Materials Center, UNIST, Korea.
authors.forename: Kwanghyun
authors.initials: K
authors.lastname: Kim
authors.forename: Myeong-Jong
authors.initials: MJ
authors.lastname: Kim
authors.forename: Sun-I
authors.initials: SI
authors.lastname: Kim
authors.forename: Ji-Hyun
authors.initials: JH
authors.lastname: Jang