Photoelectrochemical splitting of water using 170 MeV Au13+ irradiated (fluence: 10(12) and 10(13) ions cm(-2)) hematite (alpha-Fe2O3) thin film has been attempted. Enhanced photocurrent values were observed upon irradiation at fluence 10(12) ions cm(-2). However, at fluence 10(13) ions cm(-2) marginal decrease in the photocurrent was observed due to probable collapse of the initially formed tubular structures, resulting in the formation of large number of discontinuities/dislocations, which act as recombination centers for photogenerated charge carriers. The X-ray diffraction analysis exhibited diffused nature, indicating highly disordered material at 10(13) ions cm(-2). It also confirmed the inhomogeneous strain field distribution upon irradiation. Elastic recoil detection analysis exhibited no change occurring in stoichiometry of thin films throughout irradiation. Atomic force microscopy at fluence of 10(12) ions cm(-2) indicated formation of tubular. The band gap energy of these films has been found in the range of 2.01-2.08 eV, as determined by optical measurements. (c) 2005 Elsevier B.V. All rights reserved.