title: Tree branch-shaped cupric oxide for highly effective photoelectrochemical water reduction.
abstract: Highly efficient tree branch-shaped CuO photocathodes are fabricated using the hybrid microwave annealing process with a silicon susceptor within 10 minutes. The unique hierarchical, one-dimensional structure provides more facile charge transport, larger surface areas, and increased crystallinity and crystal ordering with less defects compared to irregular-shaped CuO prepared by conventional thermal annealing. As a result, the photocathode fabricated with the tree branch-shaped CuO produces an unprecedently high photocurrent density of -4.4 mA cm(-2) at 0 VRHE under AM 1.5 G simulated sunlight compared to -1.44 mA cm(-2) observed for a photocathode fabricated by thermal annealing. It is also confirmed that stoichiometric hydrogen and oxygen are produced from photoelectrochemical water splitting on the tree branch-shaped CuO photocathode and a platinum anode.
authors.affiliation: Department of Chemical Engineering, Pohang University of Science and Technology (POSTECH), San 31 Hyoja-Dong, Pohang, 790-784 South Korea.
authors.forename: Youn Jeong
authors.initials: YJ
authors.lastname: Jang
authors.forename: Ji-Wook
authors.initials: JW
authors.lastname: Jang
authors.forename: Sun Hee
authors.initials: SH
authors.lastname: Choi
authors.forename: Jae Young
authors.initials: JY
authors.lastname: Kim
authors.forename: Ju Hun
authors.initials: JH
authors.lastname: Kim
authors.forename: Duck Hyun
authors.initials: DH
authors.lastname: Youn
authors.forename: Won Yong
authors.initials: WY
authors.lastname: Kim
authors.forename: Suenghoon
authors.initials: S
authors.lastname: Han
authors.forename: Jae
authors.initials: J
authors.lastname: Sung Lee