The colloidal nanocrystal deposition process: an advanced method to prepare high performance hematite photoanodes for water splitting

Abstract

Much research has been devoted to improving the water splitting efficiency of hematite photoanodes. In this study, we demonstrate a significant advance in the colloidal nanocrystal deposition (CND) process to obtain hematite thin films with high photoelectrochemical performance. For this approach, we designed the magnetic field-assisted dip coating process to achieve homogeneous hematite thin films by using magnetic nanocrystals (maghemite) as the precursor. Using this non-aqueous deposition route, we produced undoped and Sn-doped hematite photoanodes with excellent photocurrents of 1.4 mA cm⁻² at 1.23 V_RHE and 2.7 mA cm⁻² at 1.23 V_RHE, respectively, using a standard AM1.5 G solar light simulator.