Ti(OBu)4 and cobalt iron oxide co-modified hematite nanoparticles synthesized by a facile anodic electrodeposition for highly efficient water oxidation

Based on the bare hematite prepared by a facile anodic electrodeposition, Ti(OBu)4 modified hematite through FeOOH film surface is a better method for obtaining more excellent photoelectrochemical performance. This is due to the significantly increased bulk charge separation efficiency caused by the refined grain, preferred orientation of (110) plane and higher donor density. Coupled with Cobalt Iron Oxide (CIO) nanoparticles, Ti(OBu)4 modified hematite photoanode has a 3 times enhanced photocurrent density of 1.02 mA cm−2 and a negative shift of onset potential about 40 mV compared with bare hematite photoanode. In which, Ti(OBu)4 can increase the electron-hole separation and passivate the surface trap states simultaneously. The CIO nanoparticles coated on the surface of Ti/FeOOH sample not only act as a catalyst for promoting the surface hole injection for water oxidation, but also boost the charge separation with passivating the surface states. This work provides an indepth understanding of the effect of Ti(OBu)4 and CIO nanoparticles on morphology, crystalline structure and photoelectrochemical performance of anodic electrodeposited hematite photoanode via systematical characterization with scanning electron microscopy (SEM), transmission electron microscopy (TEM), UV-vis spectra, X-ray diffractometry (XRD), X-ray photoelectron spectra (XPS), and photoelectrical measurements.