title: Charge Separation in TiO2/BDD Heterojunction Thin Film for Enhanced Photoelectrochemical Performance.
abstract: Semiconductor photocatalysis driven by electron/hole has begun a new era in the field of solar energy conversion and storage. Here we report the fabrication and optimization of TiO2/BDD p-n heterojunction photoelectrode using p-type boron doped diamond (BDD) and n-type TiO2 which shows enhanced photoelectrochemical activity. A p-type BDD was first deposited on Si substrate by microwave plasma chemical vapor deposition (MPCVD) method and then n-type TiO2 was sputter coated on top of BDD grains for different durations. The microstructural studies reveal a uniform disposition of anatase TiO2 and its thickness can be tuned by varying the sputtering time. The formation of p-n heterojunction was confirmed through I-V measurement. A remarkable rectification property of 63773 at 5 V with very small leakage current indicates achieving a superior, uniform and precise p-n junction at TiO2 sputtering time of 90 min. This suitably formed p-n heterojunction electrode is found to show 1.6 fold higher photoelectrochemical activity than bare n-type TiO2 electrode at an applied potential of +1.5 V vs SHE. The enhanced photoelectrochemical performance of this TiO2/BDD electrode is ascribed to the injection of hole from p-type BDD to n-type TiO2, which increases carrier separation and thereby enhances the photoelectrochemical performance.
authors.affiliation: Photocatalysis International Research Center, Research Institute for Science & Technology, and ‡Faculty of Science and Technology, Tokyo University of Science , 2641 Yamazaki, Noda, Chiba 278-8510, Japan.
authors.forename: Chiaki
authors.initials: C
authors.lastname: Terashima
authors.affiliation: Photocatalysis International Research Center, Research Institute for Science & Technology, and ‡Faculty of Science and Technology, Tokyo University of Science , 2641 Yamazaki, Noda, Chiba 278-8510, Japan.
authors.forename: Ryota
authors.initials: R
authors.lastname: Hishinuma
authors.affiliation: Photocatalysis International Research Center, Research Institute for Science & Technology, and ‡Faculty of Science and Technology, Tokyo University of Science , 2641 Yamazaki, Noda, Chiba 278-8510, Japan.
authors.forename: Nitish
authors.initials: N
authors.lastname: Roy
authors.affiliation: Photocatalysis International Research Center, Research Institute for Science & Technology, and ‡Faculty of Science and Technology, Tokyo University of Science , 2641 Yamazaki, Noda, Chiba 278-8510, Japan.
authors.forename: Yuki
authors.initials: Y
authors.lastname: Sugiyama
authors.affiliation: Photocatalysis International Research Center, Research Institute for Science & Technology, and ‡Faculty of Science and Technology, Tokyo University of Science , 2641 Yamazaki, Noda, Chiba 278-8510, Japan.
authors.forename: Sanjay S
authors.initials: SS
authors.lastname: Latthe
authors.affiliation: Photocatalysis International Research Center, Research Institute for Science & Technology, and ‡Faculty of Science and Technology, Tokyo University of Science , 2641 Yamazaki, Noda, Chiba 278-8510, Japan.
authors.forename: Kazuya
authors.initials: K
authors.lastname: Nakata
authors.affiliation: Photocatalysis International Research Center, Research Institute for Science & Technology, and ‡Faculty of Science and Technology, Tokyo University of Science , 2641 Yamazaki, Noda, Chiba 278-8510, Japan.
authors.forename: Takeshi
authors.initials: T
authors.lastname: Kondo
authors.affiliation: Photocatalysis International Research Center, Research Institute for Science & Technology, and ‡Faculty of Science and Technology, Tokyo University of Science , 2641 Yamazaki, Noda, Chiba 278-8510, Japan.
authors.forename: Makoto
authors.initials: M
authors.lastname: Yuasa
authors.affiliation: Photocatalysis International Research Center, Research Institute for Science & Technology, and ‡Faculty of Science and Technology, Tokyo University of Science , 2641 Yamazaki, Noda, Chiba 278-8510, Japan.
authors.forename: Akira
authors.initials: A
authors.lastname: Fujishima
keywords: BDD; TiO2; heterojunction electrode; photocatalysis; photocurrent; renewable energy; water splitting