Enhance photoelectrochemical hydrogen-generation activity and stability of TiO2 nanorod arrays sensitized by PbS and CdS quantum dots under UV-visible light

Lei Li; Haitao Dai; Liefeng Feng; Dan Luo; Shuguo Wang; Xiaowei Sun

doi:10.1186/s11671-015-1129-3

Enhance photoelectrochemical hydrogen-generation activity and stability of TiO2 nanorod arrays sensitized by PbS and CdS quantum dots under UV-visible light

Nanoscale Res Lett. 2015 Dec;10(1):418. doi: 10.1186/s11671-015-1129-3. Epub 2015 Oct 26.

Authors

Lei Li¹, Haitao Dai², Liefeng Feng¹, Dan Luo³, Shuguo Wang¹, Xiaowei Sun⁴

Affiliations

¹ Tianjin Key Laboratory of Low Dimensional Materials Physics and Preparing Technology, School of Science, Tianjin University, Tianjin, 300072, China.
² Tianjin Key Laboratory of Low Dimensional Materials Physics and Preparing Technology, School of Science, Tianjin University, Tianjin, 300072, China. htdai@tju.edu.cn.
³ Department of Electrical and Electronic Engineering, South University of Science and Technology of China, Shenzhen, 518055, China.
⁴ Nanyang Technological University, School of Electrical and Electronic Engineering, LUMINOUS! Centre of Excellence for Semiconductor Lighting and Displays, Singapore, 639798, Singapore. exwsun@ntu.edu.sg.

Abstract

We develop a composite photoanode by sensitizing TiO2 nanorod arrays with PbS quantum dots (QDs) and CdS QDs. Benefitted from additional introduced PbS QDs and CdS QDs onto TiO2, the absorption of the composite photoanodes are broaden from UV to visible region. The experimental results showed that the PbS sandwiched between TiO2 and CdS cannot only broad the absorption properties but also improve the stability. The stability can be explained by the hole facile transmission from PbS to CdS because of the valence band offsets between PbS and CdS which cause a small energy barrier and reduce the hole accumulation. The photocurrent density reached 1.35 mA cm(-2) at 0.9716 V vs. RHE (0 V vs. Ag/AgCl, under 60 mW cm(-2) illumination) for TiO2/PbS/CdS. The highest photocurrent of TiO2/PbS/CdS can be explained by the smallest of total resistance (138 Ω cm(-2)) compared to TiO2/CdS and pristine TiO2.

Keywords: Hydrogen generation; Photoelectrochemical; Solar water splitting.