Template-free fabrication of BiFeO(3)nanorod arrays: multiferroic and photo-electrochemical performances

摘要

BiFeO3(BFO) has been widely investigated in many forms and morphologies because of its combined multiferroic and photovoltaic properties. However, direct growth of vertically aligned BFO nanorods on an underlying substrate has remained a challenge. In this work, we report template free growth of BiFeO(3)nanorod arrays on fluorine doped tin oxide coated glass substrate. This has been achieved by a two-step process, in which FeOOH nanorods are grown by chemical bath deposition and converted into BFO using bismuth (Bi) coating by physical vapour deposition (PVD). Both DC sputtering and thermal evaporation are attempted under PVD and the results suggest that Bi deposited by DC sputtering leads to well-defined BFO nanorods, which show superior performance in both multiferroic and photoelectrochemical studies. Piezoelectric force microscopy data shows the signature butterfly loop that confirms piezoelectric behaviour with ad(33)value of 8 pmV(-1)in the BFO nanorods grown by DC sputtering. Further, the M-H hysteresis curve for the same samples reveals a remanent magnetization (M-r) value of 0.54 emu cc(-1)and antiferromagnetic nature at room temperature. Finally, a stable photocurrent density of 0.05 mA cm(-2)is achieved at 0.8 V vs Ag/AgCl under 1 Sun illumination. This work opens up new avenues for BFO in applications involving 1D nanostructures.