Title: Studies on hydrothermally synthesised zinc oxide nanorod arrays for their enhanced visible light photocatalysis

Authors: Mohammad Abbas Mahmood; Tanujjal Bora; Joydeep Dutta

Addresses: Department of Basic Sciences and Islamiat, University of Engineering and Technology Peshawar, Peshawar, Pakistan. ' Center of Excellence in Nanotechnology, School of Engineering and Technology, Asian Institute of Technology, Klong Luang, Pathumthani 12120, Thailand. ' Center of Excellence in Nanotechnology, School of Engineering and Technology, Asian Institute of Technology, Klong Luang, Pathumthani 12120, Thailand; Chair in Nanotechnology, Water Research Center, Sultan Qaboos University, PO Box 17, Postal Code 123, Al Khoud, Oman

Abstract: Photocatalytic activities of hydrothermally synthesised ZnO nanorod films in synergism with visible light have been studied. Influence of each of the synthesis parameters, like concentration of precursor solution, relative concentration of hexamine and zinc nitrate, growth time, growth temperature, pre-growth seeding, post-growth annealing, concentration and pH of the contaminant suspension, and light source have been investigated. Appraisal of photocatalytic efficiencies of all the synthesised samples have been done on degradation of aqueous Methylene Blue (MB) solution under artificial/ambient light. Maximum photocatalytic activities were obtained when ZnO nanorods were synthesised with equimolar concentration of 10 mM hexamine and zinc nitrate grown for 15 hr at 90°C with post-synthesis annealing at 250°C in air. Solar irradiation was found more effective than artificial white light while the activity increased exponentially with pH value of the contaminant suspension.

Keywords: hydrothermal synthesis; ZnO nanorods; zinc oxide; photocatalytic activities; parameters; visible light; solar irradiation; nanotechnology; visible light photocatalysis; nanorod films; methylene blue; hexamine; zinc nitrate; artificial white light.

DOI: 10.1504/IJETM.2013.050745

International Journal of Environmental Technology and Management, 2013 Vol.16 No.1/2, pp.146 - 159

Received: 23 Feb 2011
Accepted: 23 Jul 2011
Published online: 17 Sep 2014 *

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