Photocatalytic pure water splitting activities for ZnGa{sub 2}O{sub 4} synthesized by various methods
- College of Chemistry and Chemical Engineering, Chongqing University,Chongqing 400044 (China)
Highlights: • High temperature solid state reaction, hydrothermal, sol-gel methods were applied. • All ZnGa{sub 2}O{sub 4} samples show UV-light catalytic activities on pure water splitting. • Bulk ZnGa{sub 2}O{sub 4} has a good photocatalytic activity per specific surface area. • Sol-gel is a superior method to prepare nanosized ZnGa{sub 2}O{sub 4} with a high activity. • The AQY for SG-ZnGa{sub 2}O{sub 4} is 2.6% for pure water splitting under 313 nm irradiation. - Abstract: We studied and compared the photocatalytic water splitting performances for ZnGa{sub 2}O{sub 4} prepared by high temperature solid state reaction (HTSSR), hydrothermal (HY) and sol-gel (SG) methods. HTSSR-ZnGa{sub 2}O{sub 4} has a relative large photocatalytic activity per surface area (1.6 μmol/h/m{sup 2}) in pure water by UV irradiation due to its high crystallinity. The HY- and SG-samples both have small particle sizes (20∼30 nm) and therefore high surface area (20 and 29 m{sup 2}/g, respectively), which leads to superior photocatalytic H{sub 2} evolution rates per unit mass (11.5 and 28.5 μmol/h/g). The apparent quantum yield of SG-ZnGa{sub 2}O{sub 4} for pure water splitting under 313 nm irradiation is 2.6%. The existence of substantial surface defects is the major problem for HY- and SG-ZnGa{sub 2}O{sub 4}. Consequently, the usage of sacrificial agents could greatly enhance the activities and indeed the H{sub 2} evolution rates in 20 Vol. % methanol aqueous solution increase to 100 and 142 μmol/h/g for HY- and SG-ZnGa{sub 2}O{sub 4}, respectively.
- OSTI ID:
- 22420782
- Journal Information:
- Materials Research Bulletin, Vol. 61; Other Information: Copyright (c) 2014 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; Country of input: International Atomic Energy Agency (IAEA); ISSN 0025-5408
- Country of Publication:
- United States
- Language:
- English
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