Ni(OH)2 functionalized Zr doped α-Fe2O3 photoanode for enhanced photoelectrochemical water oxidation

Zr-doped alpha-Fe2O3 photoanodes were synthesized by hydrothermal method with a hybrid microwave annealing process. The doping percentage of Zr was optimized to have maximum photocurrent during the water oxidation process. The photoanode with optimum doping percentage was surface functionalized with Ni(OH)(2) layer. The structural, optical, morphological and electrical properties of the prepared photoanodes were studied. Moreover, the water oxidation performance of the prepared photoanodes was evaluated by measuring the photocurrent densities. The undoped alpha-Fe2O3 photoanode exhibited a photocurrent density of 0.34 mA cm 2 @ 1.23 V vs. RHE under solar radiations from the simulator, while 5 wt% of Zr doped alpha-Fe2O3 photoanode shown a photocurrent density around 1.14 mA cm 2 @ 1.23 V vs. RHE. The photocurrent of Zr doped alpha-Fe2O3 photoanode was further increased by ZF-5/N photoanode, which was about 1.45 mA cm 2 @ 1.23 V vs. RHE. The enhancement in the photocurrent density of ZF-5/N photoanode is due to the increased light absorption with higher electrical conductivity. In addition, the charge injection efficiency was increased at the interface of the surface of the photoanode and electrolyte in the presence of ZF-5/N photoanode. Also, the functionalized photoanode exhibited robust photostability over 5 h.