Ni-Fe oxide as surface promoter for oxygen evolution in photoelectrochemical water splitting

Photoelectrochemical cells (PECs), composed by an anionic polymer electrolyte membrane separator and two low-cost photoelectrodes were investigated to produce clean hydrogen by exploiting renewable solar energy [1]. In this study, a Ni-Fe oxide co-catalyst was deposited over a phosphorus-modified hematite photoanode and annealed at 450 °C. The Ni-Fe oxide appeared the most promising oxygen evolution promoter among various electrocatalysts including La0.6Sr0.4Fe0.8Co0.2O3 and IrRuOx. The loading of NiFeOx was optimized to maximise conversion efficiency. The materials were phisico-chemically characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM) and scanning electron microscopy (SEM) coupled to energy dispersive X-ray analysis (EDAX).