Photoelectrocatalytic activity of Zn-loaded RGO-TiO₂ composite coatings on mild steel substrate via DC electrochemical co-deposition

¹ Nanotechnology and Catalysis Research Centre (NANOCAT), University of Malaya, Level 3, Block A, Institute of Postgraduate Studies, University of Malaya, 50603 Kuala Lumpur, Malaysia
² School of Materials and Mineral Resources Engineering, Universiti Sains Malaysia Engineering Campus, 14300 Nibong Tebal, Seberang Perai Selatan, Pulau Pinang, Malaysia
³ School of Materials Engineering Universiti Malaysia Perlis (UniMAP), Taman Muhibbah, 02600 Arau, Perlis, Malaysia

^a e-mail: cwlai@um.edu.my
^b e-mail: sharifahbee@um.edu.my

Received: 11 September 2013
Revised: 13 October 2013
Accepted: 20 December 2013
Published online: 3 February 2014

Abstract

The photoelectrocatalytic activity of Zn-loaded reduced graphene oxide-titania (RGO-TiO₂) composite coatings on mild steel substrate was investigated in detail. Zn-loaded RGO-TiO₂ composite films were prepared by using DC electrochemical co-deposition technique onto mild steel substrate in an acid-sulphate bath electrolyte. The cyclic voltammetry and photocurrent response studies showed that the Zn-loaded RGO-TiO₂ films have improved photoelectrocatalytic performance. The embedding of metallic Zn into the RGO-TiO₂ promoted an effective charge carriers separation by minimizing the recombination losses. In this manner, metallic Zn will act as efficient photo-induced electron acceptors from the bulk of RGO-TiO₂ film. Thus, the transportation of the electrons from the working electrode to the counter electrode was improved significantly.