Photodeposition of AuNPs on metal oxides: Study of SPR effect and photocatalytic activity Sadhana S. Rayalu a,b, *, Deepa Jose c,1 , Priti A. Mangrulkar b,1 , Meenal Joshi b , Girivyankatesh Hippargi b , Khadga Shrestha c , Kenneth Klabunde c a CSIR-Network Institute of Sustainable Energy (CSIR-NISE), India b Environmental Material Division, CSIR-National Environmental Engineering Research Institute (CSIR-NEERI), Nagpur 440 020, India c Department of Chemistry, Kansas State University, Manhattan, KS 66506, United States article info Article history: Received 11 February 2013 Received in revised form 20 November 2013 Accepted 29 November 2013 Available online 28 January 2014 Keywords: AuNPs Photocatalytic hydrogen Photodeposition Visible light abstract Effect of photodeposition of AuNPs (gold nanoparticles) on TiO 2 , CeO 2 , Cu 2 O and Fe 3 O 4 supports has been illustrated on sacrificial donor based hydrogen evolution. The synthe- sized samples were characterized by diffuse reflectance spectroscopy (DRS), and trans- mission electron microscopy (TEM). Highest photocatalytic activity was exhibited by Au/ TiO 2 followed by Au/Fe 3 O 4 , Au/CeO 2 and Au/Cu 2 O. Au/TiO 2 under optimized conditions has shown significantly high photocatalytic activity under both UVevisible and visible radia- tion. Au/TiO 2 shows hydrogen evolution rate of 920 mmol h 1 and 32.4 mmol h 1 under UV evisible and visible radiation, respectively. Significant enhancement in hydrogen evolution rate under visible light is very encouraging and may be attributed to polydispersed nature of AuNPs wherein larger particles facilitate light absorption and the smaller function as catalytic sites. Further studies are in progress to study the influence of various parameters on photocatalytic activity of Au/TiO 2. Copyright ª 2013, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved. 1. Introduction In pursuit of finding an alternative source of renewable en- ergy, the current research scenario is primarily focussed on photocatalytic solar hydrogen production as it promises a clean and green route of generating hydrogen. Over the years, TiO 2 has garnered a lot of attention in the field of photocatalysis, courtesy its abundance, non-toxicity and low cost. However, the major hurdle which limits the application of TiO 2 in photocatalytic hydrogen production is the fast recombination of its photogenerated electron and holes and its inability to utilize the visible radiation. Noble metal loading (Au, Ag, Pt etc) is one of the routes employed for sensitizing TiO 2 and has proved in significantly enhancing the photoactivity of TiO 2 . The underlying mech- anism being that the Fermi level of the metal is lower than TiO 2 and hence there can be an electron transfer from the conduction band of the semiconductor to the metal [1]. This consequently leads to significant reduction in the * Corresponding author. Environmental Material Division, CSIR-National Environmental Engineering Research Institute (NEERI, C.S.I.R.), Nagpur 440 020, India. Tel./fax: þ91 712 2247828. E-mail address: s_rayalu@neeri.res.in (S.S. Rayalu). 1 Both authors have contributed equally. Available online at www.sciencedirect.com ScienceDirect journal homepage: www.elsevier.com/locate/he international journal of hydrogen energy 39 (2014) 3617 e3624 0360-3199/$ e see front matter Copyright ª 2013, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved. http://dx.doi.org/10.1016/j.ijhydene.2013.11.120