LAUSR

Abstract To tackle the problem of bulk recombination and to solve the holes diffusion issue in hematite, the shape-guiding and in situ doping is an effective strategy. Herein, we developed a novel strategy for designing and fabricating zirconium-doped transparent hematite (Zr-Fe2O3(I)) photoanode through an in situ hydrothermal method and stoichiometric iron and zirconium dilution. The concentration of ZrO(NO3)2 and FeCl3·6H2O in the precursor solution effectively influenced the transparency and morphology of zirconium-doped Fe2O3. The XPS and TEM analyses confirms the co-existence of Zr doping and surface modification of Fe2O3 nanocoral diffused ZrO2 after high temperature quenching. Synergism between the Zr doping and ZrO2 layer facilizes the charge transfer in Zr-Fe2O3 nanocoral (NC) photoanodes. Among the photoanodes prepared by variously diluted concentrations of the iron and zirconium precursor, the in situ 1/32 Zr-Fe2O3 nanocoral (NC) photoanode achieved an excellent photocurrent density of 1.55 mA cm2 at 1.23 V vs. RHE, which is about doubles than that of the conventional pristine Fe2O3 (P-Fe2O3) NR. Additionally, as result of in situ Zr doping, favorable nanocoral morphology and ZrO2 surface modification exhibits the decreased changer transfer resistance and increased incident photon to current efficiency (IPCE) of 1/32 Zr-Fe2O3 NC upto 21.9%. This in situ Zr-doping and nanocoral morphology 1/32 Zr-Fe2O3 fulfills the requirements of both high charge separation efficiency and improved water oxidation kinetics. A novel 1/32 Zr-Fe2O3 (I) NC photoanode exhibits O2 and H2 evolution up to 69 and 138 μmol during 5 h of overall pure water splitting. This novel in situ hydrothermal dilution approach is feasible for fabricating a transparent hematite photoanode with NC morphology for practical PEC water splitting.