α-Fe2O3/AmTiO2 heterojunction-based photoanode with improved interfacial charge transport properties for enhanced photoelectrochemical water splitting

To improve the photoelectrochemical water-splitting performance of the alpha-Fe2O3 photoanode, in this work, we synthesized the alpha-Fe2O3/AmTiO2 (Am = Amorphous) heterojunction on fluorine-doped tin oxide substrate with improved charge transport properties. Two different compositions of alpha-Fe2O3/ AmTiO2 heterojunctions were synthesized by varying the titanium precursor and were named as a-Fe2O3/AmTiO2-1 and alpha-Fe2O3/AmTiO2-2. The crystal structure, morphology, and optical properties were studied using different characterization techniques. Compared with the alpha-Fe2O3 nanostructure, the formation of alpha-Fe2O3/AmTiO2-2 heterojunction increases the photocurrent density at 1.23 V vs RHE in threefold. It is observed that amorphous TiO2 could offer high electrical conductivity with enhanced charge transport properties along with a minimum of photoexcited charge carrier's recombination rates and, thus, enhances the water-splitting performance under the simulated solar illumination. The results demonstrate the new way for the preparation of alpha-Fe2O3/ AmTiO2 heterojunction towards efficient water-splitting application.