Description:
<jats:p>In this study, a promising alternative method for addressing grain boundary issues in hematite (α‐Fe<jats:sub>2</jats:sub>O<jats:sub>3</jats:sub>)‐based photoanodes is presented. The porous α‐Fe<jats:sub>2</jats:sub>O<jats:sub>3</jats:sub> films are prepared by dip coating a polymerizable precursor onto fluorine‐doped tin oxide (FTO) substrates. The photoelectrochemical (PEC) performance of α‐Fe<jats:sub>2</jats:sub>O<jats:sub>3</jats:sub> photoanodes is characterized and optimized through controlling the annealing temperature and the number of deposition cycles. Samples of improved crystallinity consisting of a layer of hematite particles of 50 nm in diameter exhibit highest photoresponses of 1.04 mA cm<jats:sup>−2</jats:sup> at 1.23 V versus a reversible hydrogen electrode (RHE), and 2.0 mA cm<jats:sup>−2</jats:sup> before the dark current onset at 1.7 V<jats:sub>RHE</jats:sub>. This study indicates that the PEC performance of hematite can be enhanced greatly by an improved crystallinity, particle texture, and a better control of grain boundary effects.</jats:p>