Surface-area-tuned, quantum-dot-sensitized heterostructured nanoarchitectures for highly efficient photoelectrodes
photoelectrochemical, hydrogen evolution, antimony-doped tin oxide, TiO2, quantum dot
ABSTRACT Harvesting solar energy to produce clean hydrogen from photoelectrolysis of water presents a valuable opportunity to find alternatives for fossil fuels. Three- dimensional nanoarchitecturing techniques can afford enhanced photoelec-trochemical properties by improving geometrical and structural effects. Here, we report quantum-dot sensitized TiO2–Sb:SnO2 heterostructures as a model electrode to enable the optimization of the structural effects through the creation of a highly conductive pathway using a transparent conducting oxide (TCO), coupled with a high surface area, by introducing branching and low interfacial resistance via an epitaxial relationship. An examination of various morphologies (dot, rod, and lamella shape) of TiO2 reveals that the rod-shaped TiO2–Sb:SnO2 is a more effective structure than the others. A photoelectrode fabricated using optimized CdS–TiO2–Sb:SnO2 produces a photocurrent density of 7.75 mA/cm2 at 0.4 V versus a reversible hydrogen electrode. These results demonstrate that constructing a branched heterostructure based on TCO can realize high- performance photoelectrochemical devices.
Tsinghua University Press
Sangbaek Park,Donghoe Kim,Chan Woo Lee,Seong-Deok Seo,Hae Jin Kim,Hyun Soo Han,Kug Sun Hong,Dong-Wan Kim, Surface-area-tuned, quantum-dot-sensitized heterostructured nanoarchitectures for highly efficient photoelectrodes. NanoRes.2014, 7(1): 144-153