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Cadmium Sulfide Quantum Dots Supported on Gallium and Indium Oxide for Visible‐Light‐Driven Hydrogen Evolution from Water
Author(s) -
Pan Yunxiang,
Zhuang Huaqiang,
Hong Jindui,
Fang Zheng,
Liu Hai,
Liu Bin,
Huang Yizhong,
Xu Rong
Publication year - 2014
Publication title -
chemsuschem
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.412
H-Index - 157
eISSN - 1864-564X
pISSN - 1864-5631
DOI - 10.1002/cssc.201402334
Subject(s) - quantum dot , cadmium sulfide , photocurrent , indium , materials science , oxygen evolution , photoluminescence , oxide , visible spectrum , water splitting , photochemistry , nanoparticle , aqueous solution , chemistry , inorganic chemistry , photocatalysis , nanotechnology , electrochemistry , optoelectronics , catalysis , electrode , biochemistry , metallurgy
In this work, CdS quantum dots (QDs) supported on Ga 2 O 3 and In 2 O 3 are applied for visible‐light‐driven H 2 evolution from aqueous solutions that contain lactic acid. With Pt as the cocatalyst, the H 2 evolution rates on CdS/Pt/Ga 2 O 3 and CdS/Pt/In 2 O 3 are as high as 995.8 and 1032.2 μmol h −1 , respectively, under visible light ( λ >420 nm) with apparent quantum efficiencies of 43.6 and 45.3 % obtained at 460 nm, respectively. These are much higher than those on Pt/CdS (108.09 μmol h −1 ), Pt/Ga 2 O 3 (0.12 μmol h −1 ), and Pt/In 2 O 3 (0.05 μmol h −1 ). The photocatalysts have been characterized thoroughly and their band structures and photocurrent responses have been measured. The band alignment between the CdS QDs and In 2 O 3 can lead to interfacial charge separation, which cannot occur between the CdS QDs and Ga 2 O 3 . Among the various possible factors that contribute to the high H 2 evolution rates on CdS/Pt/oxide, the surface properties of the metal oxides play important roles, which include (i) the anchoring of CdS QDs and Pt nanoparticles for favorable interactions and (ii) the efficient trapping of photogenerated electrons from the CdS QDs because of surface defects (such as oxygen defects) based on photoluminescence and photocurrent studies.