Electrodeposition of Sn-doped hollow α-Fe2O3 nanostructures for photoelectrochemical water splitting

•Fabricating hollow structure α-Fe2O3 film on hard template by electrodeposition.•Morphology of α-Fe2O3 film is changed largely by Sn concentration in electrolyte.•Nanocrystals in hollow structure α-Fe2O3 film separate carries effectively.•Photocurrent of the α-Fe2O3 film can be enhanced by Sn4+ doping.

The hollow nanostructured hematite photoanodes were prepared by using template-assisted electrodeposition and heat-treatment process. The morphologies of the films were regulated through the synthesis parameters such as potential sweep rate, annealing temperature and Sn concentration in electrolyte, and confirmed by scanning electron microscopy and transmission electron microscopy. Sn-doping of hematite was achieved by using electrolyte containing tin salt. The photocurrent of Sn-doped hematite film reaches 0.25 mA/cm2 in 1 M NaOH at 1.23 V vs. RHE by optimizing the synthesis parameters. It is noted that both Sn doping and hollow nanostructure can affect and improve the PEC performance of hematite film.