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Title: Photocatalytic pure water splitting activities for ZnGa{sub 2}O{sub 4} synthesized by various methods

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}.more » 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.« less
Authors:
 [1] ;  [2] ; ; ; ;  [1] ;  [1] ;  [1]
  1. College of Chemistry and Chemical Engineering, Chongqing University,Chongqing 400044 (China)
  2. (China)
Publication Date:
OSTI Identifier:
22420782
Resource Type:
Journal Article
Resource Relation:
Journal Name: Materials Research Bulletin; Journal Volume: 61; Other Information: Copyright (c) 2014 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; AQUEOUS SOLUTIONS; COMPARATIVE EVALUATIONS; GALLIUM OXIDES; HYDROGEN; IRRADIATION; METHANOL; NANOSTRUCTURES; PARTICLE SIZE; PHOTOCATALYSIS; SEMICONDUCTOR MATERIALS; SOL-GEL PROCESS; SOLIDS; SURFACE AREA; SURFACES; SYNTHESIS; ULTRAVIOLET RADIATION; WATER; ZINC COMPOUNDS