Hydrothermal fabrication and analysis of piezotronic-related properties of BiFeO3 nanorods

This paper reports the fabrication of vertically oriented BiFeO3 (BFO) nanorods on indium tin oxide/glass substrates through hydrothermal synthesis. Further, their piezotronic, piezophototronic, and piezophotocatalytic properties were analyzed. Various synthesis parameters were examined to modulate the morphology and alignment of BFO nanorods, including the ratios of precursors, the pH values, types of complex agents, and reaction times and temperatures. Transmission electron microscopy results demonstrated single crystallinity of the BFO nanorods. A band gap of approximately 2.3 eV was determined. The piezotronic and piezophototronic properties were observed through facile current-voltage measurement. The extended application of piezophotocatalysis under alternating external stress and visible-light irradiation, to decompose methylene blue solutions, was also ascertained. The piezophotocatalytic efficiency was improved by approximately 30% over photocatalysis in the first 30 min. Both O-2(-) square and square center dot OH radicals were crucial for these activities.