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

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.