3D branched nanowire heterojunction photoelectrodes for high-efficiency solar water splitting and H2 generation.
We report the fabrication of a three dimensional branched ZnO/Si heterojunction nanowire array by a two-step, wafer-scale, low-cost, solution etching/growth method and its use as photoelectrode in a photoelectrochemical cell for high efficiency solar powered water splitting. Specifically, we demonstrate that the branched nanowire heterojunction photoelectrode offers improved light absorption, increased photocurrent generation due to the effective charge separation in Si nanowire backbones and ZnO nanowire branching, and enhanced gas evolution kinetics because of the dramatically increased surface area and decreased radius of curvature. The branching nanowire heterostructures offer direct functional integration of different materials for high efficiency water photoelectrolysis and scalable photoelectrodes for clean hydrogen fuel generation.
Department of Electrical and Computer Engineering, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA 92093, USA.
Ke
K
Sun
Yi
Y
Jing
Chun
C
Li
Xiaofeng
X
Zhang
Ryan
R
Aguinaldo
Alireza
A
Kargar
Kristian
K
Madsen
Khaleda
K
Banu
Yuchun
Y
Zhou
Yoshio
Y
Bando
Zhaowei
Z
Liu
Deli
D
Wang
D004566:Electrodes; D004573:Electrolytes / Q000737:chemistry; D006859:Hydrogen / Q000737:chemistry*; D007700:Kinetics; D008027:Light; D053770:Nanowires / Q000737:chemistry* / Q000648:ultrastructure; D012825:Silicon / Q000737:chemistry*; D014867:Water / Q000737:chemistry*; D015034:Zinc Oxide / Q000737:chemistry*
D004573:Electrolytes; D014867:Water; D006859:Hydrogen; D015034:Zinc Oxide; D012825:Silicon