A dip coating process for large area silicon-doped high performance hematite photoanodes

A facile and low-cost dip-coating process for the deposition of silicon doped hematite films (Si:alpha-Fe2O3) for hydrogen production by solar water splitting in photo-electrochemical cells (PEC) is presented. The precursors include iron nitrate, oleic acid, tetraethyl orthosilicate (TEOS) and tetrahydrofuran as dispersion agent. Sequential dip coating on transparent conducting oxides glass substrates with heat treatment steps at 500 degrees C and 760 degrees C yields mesoporous Si:alpha-Fe2O3 with a roughness factor of 17 and photocurrent densities >1 mA/cm(2) at 1.23 V vs. reversible hydrogen electrode with SiOx underlayer and surface modification. A PEC demonstrator with 80 cm(2) active area in 1 M potassium hydroxide yields a photocurrent of 35 mA at 1.5 AM irradiation with the corresponding hydrogen evolution at a Pt wire counter electrode. (C) 2013 AIP Publishing LLC.