Enhanced photoelectrochemical response of reduced graphene oxide covered inexpensive TiO2-BiFeO3 composite photoanodes

Abstract

We show enhanced photoelectrochemical response of reduced graphene oxide covered inexpensive TiO2-BiFeO3 composite photoanodes for photoelectrochemical water splitting reaction. The photoelectrochemical activity of TiO2-BiFeO3 composite electrode is increased by creating heterojunction of TiO2-BiFeO3 and rGO. Structural, optical and morphological analysis of pristine and composite samples was done by characterizing them using X-ray diffraction, UV–vis spectrometry and scanning electron microscopy. The photoelectrochemical water splitting reaction revealed that composite TiO2-BiFeO3 with 20 wt.% BiFeO3 has higher photocurrent density. Further this composite electrode with rGO layer exhibits more than tenfold photocurrent density at onset and as well as higher potential. Graphene oxide layer acts as rich source of electrons caused better separation of the photogenerated electron hole pairs at heterojunction. Finally, this system shows high photocurrent density of 3.5 mA cm−2 at 0.95 V/Ag/AgCl with good stability under light conditions.