Porous Hematite Photocatalytic Structures on Freestanding CuO-Sb₂O₅-SnO₂ Ceramics for Solar-Driven Water Splitting and Flow-Through Water Purification

High porosity and large photoactive surface of photoelectrodes grown on nano-grained and conductive ceramics provide freestanding structures for applications in photoelectrolysis and flow-through water purification. This study presents unmodified hematite photoelectrodes grown on CuO-Sb₂O₅-SnO₂ ceramics, exhibiting photocurrent density of 0.63 mA cm⁻² at 1.23 V versus a reversible hydrogen electrode (RHE) under AM1.5G radiation. The obtained photoelectrodes are tested for cleaning seawater contaminated with methylene blue. The photocatalytic structures are examined by photoelectrochemical measurements, x-ray diffraction, scanning electron microscopy, energy-dispersive x-ray spectroscopy, x-ray photoelectron spectroscopy, ultraviolet–visible spectroscopy, and Raman spectroscopy. The influence of substrate temperature on photocurrents obtained with these photoelectrodes is studied and discussed.