TiO2 promoted by two different non-noble metal cocatalysts for enhanced photocatalytic H2 evolution

• Published in: Applied surface science Vol. 309; pp. 188 - 193
• Main Authors: Lin, Jing-Dong, Yan, Shi, Huang, Qin-Dong, Fan, Mei-Ting, Yuan, You-Zhu, Tan, Timothy Thatt-Yang, Liao, Dai-Wei
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 01.08.2014; Elsevier
• Subjects: Cobalt; Cocatalyst; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Condensed matter: structure, mechanical and thermal properties; Cross-disciplinary physics: materials science; rheology; Evolution; Exact sciences and technology; Nickel; Noble metals; Non-nobel metal; Photocatalysis; Photocatalysts; Photocatalytic hydrogen evolution; Physics; Strategy; Synergistic effect; Titanium dioxide; Non-nobel metal; Nickel; Photocatalytic hydrogen evolution; Synergistic effect; Cocatalyst; Cobalt; Inorganic compounds; Hydrogen; Transition elements; Transition element compounds; Titanium oxide
• ISSN: 0169-4332; 1873-5584
• DOI: 10.1016/j.apsusc.2014.05.008

•Ni and Co were used as HER and OR cocatalysts for photocatalytic H2 evolution.•Ni and Co are the promising substitutes for noble metals as HER and OR cocatalysts.•A synergistic effect of cobalt and nickel was found on 0.1%Co+0.2%Ni/TiO2.•TiO2 promoted by Co and Ni shows more photocatalytic activity for H2 evolution. TiO2 photocatalysts modified by cobalt and nickel cocatalysts were prepared via polymerized complex method (PCM) and evaluated by photocatalytic hydrogen evolution. Hydrogen generation in 6h for the TiO2 promoted by cobalt and nickel (0.1%Co+0.2%Ni/TiO2) is about two times (2456μmol H2) compared to that of TiO2 promoted only by cobalt (1180μmol H2 for 0.1%Co/TiO2) or nickel (1127μmol H2 for 0.2%Ni/TiO2), and mechanically mixed TiO2 promoted by cobalt and TiO2 promoted by nickel (0.1%Co/TiO2:0.2%Ni/TiO2=1:1 (m/m), 1282μmol H2). The high photocatalytic H2 evolution activity over TiO2 promoted by cobalt and nickel is ascribed to enhanced photo response due to the presence of cobalt and nickel impurity level, and effective separation of photogenerated electrons and holes due to the synergistic effect of cobalt and nickel, which serve as active sites for H2 evolution reaction (HER) and oxidation reaction (OR) respectively. This study demonstrates a viable strategy to design more active photocatalysts for photocatalytic H2 evolution by substituting noble metals with more abundant elements using as HER and OR cocatalysts, respectively.