title: Hierarchical top-porous/bottom-tubular TiO2 nanostructures decorated with Pd nanoparticles for efficient Photoelectrocatalytic decomposition of synergistic pollutants.
abstract: In this paper, top-porous and bottom-tubular TiO(2) nanotubes (TiO(2) NTs) loaded with palladium nanoparticles (Pd/TiO(2) NTs) were fabricated as an electrode for an enhanced photoelectrocatalytic (PEC) activity toward organic dye decomposition. TiO(2) NTs with a unique hierarchical top-porous and bottom-tubular structure were prepared by a facile two-step anodization method and Pd nanoparticles were decorated onto the TiO(2) NTs via a photoreduction process. The PEC activity of Pd/TiO(2) NTs was investigated by decomposition of methylene blue (MB) and Rhodamine B (RhB). Because of formation Schottky junctions between TiO(2) and Pd, which significantly promoted the electron transfer and reduced the recombination of photogenerated electrons and holes,  the Pd/TiO(2) NT electrode showed significantly higher PEC activities than TiO(2) NTs. Interestingly, an obvious synergy between two dyes was observed and corresponding mechanism based on facilitated transfer of electrons and holes as a result of a suitable energy level alignment was suggested. The findings of this work provide a fundamental insight not only into the fabrication but also utility of Schottky junctions for enhanced environmental remediation processes.
authors.affiliation: Water Desalination and Reuse Center, Chemical and Life Science and Engineering Division, King Abdullah University of Science and Technology, Thuwal 23955-6900, Kingdom of Saudi Arabia.
authors.forename: Zhonghai
authors.initials: Z
authors.lastname: Zhang
authors.forename: Yanjie
authors.initials: Y
authors.lastname: Yu
authors.forename: Peng
authors.initials: P
authors.lastname: Wang