High-density ZnSnO3 nanowire arrays fabricated using single-step hydrothermal synthesis

This study examined the fabrication of high-density rhombohedral ZnSnO₃ nanowire arrays on fluorine-doped SnO₂ (FTO) substrates through single-step hydrothermal synthesis and their synergistic piezo-related performance. The band gap (approximately 3.7 eV) and valence band (E_v) position (approximately 2.7 eV below the Fermi energy of Au approximately ?4.9 eV]) of the arrays were obtained using ultraviolet-visible (UV-Vis) spectrometry and UV photoelectron spectroscopy, respectively. An energy band diagram was obtained, revealing the favorable band positions of the samples for photodegradation and water splitting. Reliable and superior piezophotodegradation capability with a degradation rate constant of approximately 17.6 × 10^?3 min^?1 was also observed. Holes and ?OH were predominant for the degradation mechanism, as determined by scavenger studies. Moreover, the samples exhibited favorable piezophotoelectrochemical (PPEC) performance, which was validated by the obtained applied bias photon-to-current efficiency. The stress-induced photocurrent density observed in a PPEC reaction was more than twice that observed in a photoelectrochemical reaction. Both piezophotodegradation and PPEC reactions were attributable to the inhibition of electron-hole pair recombination because of the excellent alignment of the nanowires, piezopotential buildup, and band bending of the ZnSnO₃ nanowires. Our results indicate a positive effect of piezoelectricity on the piezo-related applications of the sample.