Enhanced photocatalytic and photoelectrochemical activities of reduced TiO _2-x /BiOCl heterojunctions

Journal Article · Fri Apr 01 00:00:00 EDT 2016 · Journal of Power Sources

DOI:https://doi.org/10.1016/j.jpowsour.2016.02.038· OSTI ID:1416006

Fu, Rongrong; Zeng, Xiaoqiao ; Ma, Lu; Gao, Shanmin; Wang, Qingyao; Wang, Zeyan; Huang, Baibiao; Dai, Ying; Lu, Jun

A key issue to design highly efficient photoelectrodes for hydrogen production is how to prohibit the rapid carrier recombination. In order to use the visible light and reduce the recombination of electrons and holes, reduced TiO_2-x/BiOCl heterojunctions are successfully synthesized and the photoelectrodes are assembled in this work. The effects of various Bi/Ti molar ratios on the structural, morphological, optical, photoelectrochemical and photocatalytic activities of the resultant samples are investigated systematically. The TiO_2-x nanoparticles contain Ti³⁺, Ti²⁺, and oxygen vacancies (Ov), while the BiOCl nanosheets exposed {001} facet. Ultraviolet–visible diffuse reflectance spectroscopy (UV–vis DRS) results indicate that the existence of Ti³⁺, Ti²⁺ and Ov expand the light-response range. Linear scan voltammetry and electrochemical impedance spectroscopy results indicate that more efficient electron transportation is presented in the heterojunctions with the appropriate Bi/Ti molar ratio. Consequently, the reduced TiO_2-x/BiOCl heterojunction with the most appropriate Bi/Ti molar ratio exhibits a high photocurrent density of 0.755 mA cm^-2 with photoconversion efficiency up to 0.634%, 10.5 and 22.6 times larger than that of pure TiO₂ and BiOCl. Furthermore, this heterojunction exhibit 48.38 and 12.54 times enhancement for the visible-light decomposition of rhodamine B compared with pure TiO₂ and BiOCl.

• Research Organization: Argonne National Lab. (ANL), Argonne, IL (United States)
• Sponsoring Organization: USDOE Office of Energy Efficiency and Renewable Energy (EERE)
• DOE Contract Number: AC02-06CH11357
• OSTI ID: 1416006
• Journal Information: Journal of Power Sources, Vol. 312, Issue C; ISSN 0378-7753
• Publisher: Elsevier
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
Hydrothermal treatment
BiOCl
Heterojunctions
Photoelectrochemical water-splitting
Reduced TiO2-x
Visible-light photocatalyst