Single step synthesis of (alpha-Fe2O3) hematite films by hydrothermal electrochemical deposition

Abstract

A single step electrodeposition of alpha-Fe2O3 films under hydrothermal conditions without post-annealing requirement is described. Primary attention is paid to understand the effects of synthesis conditions, such as temperature, precursor concentration, pH, and time on the structure and morphology of the films. Moreover, the photoelectrochemical properties of hematite films grown by hydrothermal-electrochemical deposition (HED) are also discussed. It is discovered that HED enables the production of crystalline alpha-Fe2O3 phase without thermal annealing as opposed to electrodepositions reported at ambient temperature. Photoelectrochemical studies demonstrated that better performance can be obtained with the films prepared at higher pH. A net photocurrent density of 23.6 mu A cm(-2) is obtained in 0.1 M NaOH under 1 sun conditions at 1.23 V vs. NHE with the film prepared from a bath containing 0.05 M FeCl2 and 0.2 M NaCH3COO via hydrothermal-electrodeposition with a photocurrent onset potential of 0.96 V vs. NHE.