Coverage control of CdSe quantum dots in the photodeposition on TiO2 for the photoelectrochemical solar hydrogen generation.
CdSe quantum dots (QDs) have successfully been formed on the TiO2 surface by the photodeposition of Se QDs and their subsequent transformation into CdSe QDs (CdSe/TiO2) (Fujishima et al., 2014). The addition of mercaptoacetic acid (MAA) in the second step of the two-step photodeposition process significantly decreases the CdSe particle size and the contact angle against the TiO2 surface to increase the TiO2-surface coverage by CdSe QDs with the particle size distribution sharpened. X-ray photoelectron and Raman spectroscopy measurements indicated that MAA is densely chemisorbed on the surface of CdSe QDs through CdS bond, whereas sparsely adsorbed on the TiO2 surface. Photoelectrochemical (PEC) cells using CdSe/TiO2 as the photoanode for hydrogen (H2) generation from aqueous sulfide solution were fabricated. The rate of H2 generation strongly depends on the concentration of MAA (C) added in the photoanode preparation, and the photoanode prepared at C=0.04mM affords a maximum solar-to-hydrogen conversion efficiency of 0.028%.
Department of Applied Chemistry, School of Science and Engineering, Kinki University, 3-4-1, Kowakae, Higashi-Osaka, Osaka 577-8502, Japan.
Mari
M
Yoshii
Department of Applied Chemistry, School of Science and Engineering, Kinki University, 3-4-1, Kowakae, Higashi-Osaka, Osaka 577-8502, Japan.
Yusuke
Y
Murata
Department of Applied Chemistry, School of Science and Engineering, Kinki University, 3-4-1, Kowakae, Higashi-Osaka, Osaka 577-8502, Japan.
Yasunari
Y
Nakabayashi
Department of Applied Chemistry, School of Science and Engineering, Kinki University, 3-4-1, Kowakae, Higashi-Osaka, Osaka 577-8502, Japan.
Takuya
T
Ikeda
Department of Applied Chemistry, School of Science and Engineering, Kinki University, 3-4-1, Kowakae, Higashi-Osaka, Osaka 577-8502, Japan.
Musashi
M
Fujishima
Department of Applied Chemistry, School of Science and Engineering, Kinki University, 3-4-1, Kowakae, Higashi-Osaka, Osaka 577-8502, Japan. Electronic address: h-tada@apch.kindai.ac.jp.
Hiroaki
H
Tada
CdSe; Hydrogen; Photodeposition; Photoelectrochemical cell; Quantum dots; TiO(2)