Transparent Zirconium-doped Hematite Nanocoral Photoanode via In-Situ Diluted Hydrothermal Approach for Efficient Solar Water Splitting

•Zr-Fe2O3(I) photoanode was prepared via novel in situ hydrothermal dilution method.•Stoichiometric Fe and Zr dilution played key role in growth of Fe2O3(I) Nanocorals.•1/32 Zr-Fe2O3(I) NC exhibited the photocurrent density of 2.0 mA/cm2 at 1.4 VRHE.•Zr and Sn doping can effectively inhibited the charge recombination in Nanocorals.•The maximum 69 and 138 μmol of O2 and H2 evolution was achieved after 5 h.