Journal
APPLIED CATALYSIS B-ENVIRONMENTAL
Volume 239, Issue -, Pages 398-407Publisher
ELSEVIER
DOI: 10.1016/j.apcatb.2018.08.029
Keywords
Oxygen vacancy; Defect engineering; Tungsten trioxide; Visible light photocatalysis; Charge-carriers separation
Funding
- National Natural Science Foundation of China [21476159, 21676182]
- 973 program [2014CB932403]
- Program of Introducing Talents of Disciplines to China Universities [B06006]
Ask authors/readers for more resources
Defect engineering is a promising strategy to enhance light absorption and charge separation of photocatalysts. Herein, we simply tailor the quantity and distribution of oxygen vacancies, as one of typical defects, on surface or bulk of thermal-treated WO3 in the different H-2 concentration. The quantity of bulk oxygen vacancies on WO3 consistently rises with the increased H-2 concentration, while that of surface oxygen vacancies presents a volcano type variation. The sample of WO3-H20, thermal-pretreated in 20% H-2, contains the largest amount of surface oxygen vacancies. Our results show that both surface and bulk oxygen vacancies on WO3 can promote the visible light photocatalytic activity in water splitting, however, in different ways. Bulk oxygen vacancies mainly promote the visible light harvesting and slightly restrain the electrons and holes recombination by narrowing band gap energy (E-g), while surface oxygen vacancies significantly increase the charge-carriers separation efficiency by lowering valence band edge (VBE). Compared with the light absorption, the separation of electrons and holes is more critical in photocatalytic oxygen evolution over WO3, revealing the more decisive role of surface oxygen vacancies than bulk oxygen vacancies. Expectedly, WO3-H20 shows the highest charge-carriers separation efficiency and visible light photocatalytic performance. Our work provides a new insight into designing of efficient defect-engineered semiconductors for the related solar light utilization processes.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available