Effect of growth time on morphology and photoelectrochemical performance of TiO₂ nanorod arrays grown on transparent conducting substrates

Abstract

TiO₂ nanorod arrays (NRAs) were synthesized directly on the fluorine tin oxide (FTO) coated glass substrates by a facile hydrothermal route. The effects of growth time on the photoelectrochemical (PEC) properties of TiO₂ NRAs are investigated. The samples synthesized for 4 h exhibit a photocurrent intensity of 0.37 mA/cm² at the irradiation of Xe lamp and a bias of 0 V. As the growth time increases, the thickness and order degree of the NRAs are enhanced, but the photocurrent is reduced a lot. It might be associated with the hindering of a high background electron density in NRs due to the long-time hydrothermal reaction in acid environment. Moreover, the decline behavior is observed, which is attributed to the poor charge separation capacity of TiO₂ array electrodes and could be suppressed efficiently by applying a suitable positive bias.

References

[1] MaY., WangX., JiaY., ChenX., HanH., LiC.. Chem. Rev., 2014, 114: 9987

[2] WuH.B., HngH.H., LouX.W.. Adv. Mater., 2012, 24: 2567

[3] O’ReganB., GräztelM.. Nature, 1991, 353: 737

[4] MathewS., YellaA., GaoP., Humphry-BakerR., CurchodB. F. E., Ashari-AstaniN., TavernelliI., RothlisbergerU., NazeeruddinMd. K., GrätzelM.. Nat. Chem., 2014, 6: 242

[5] TongH., OuyangS., BiY., UmezawaN., OshikiriM., YeJ.. Adv. Mater., 2012, 24: 229

[6] DuC., YangX., MayerM.T., HoytH., XieJ., McMahonG., BischopingG., WangD.. Angew. Chem. Int. Ed., 2013, 52: 12692

[7] JoW.J., JangJ.W., KongK., KangH.J., KimJ.Y., JunH., ParmarK.P.S., LeeJ.S.. Angew. Chem. Int. Ed., 2012, 51: 3147

[8] ZouZ., YeJ., SayamaK., ArakawaH.. Nature, 2001, 414: 625

[9] LiuB., AydilE.S.. J. Am. Chem. Soc., 2009, 131: 3985

[10] GuX.Q., ZhaoY.L., QiangY.H.. J. Mater. Sci. Mat. Electron., 2012, 23: 1373

[11] WangH., BaiY., ZhangH., ZhangZ., LiJ., GuoL.. J. Phys. Chem. C, 2010, 114: 16451

[12] WangC., ChenZ., JinH., CaoC., LiJ., MiZ.. J. Mater. Chem. A, 2014, 2: 17820

[13] WangX., XieJ., LiC. M.. J. Mater. Chem. A, 2015, 3: 1235

[14] SuJ., GuoL., BaoN., GrimesC.A.. Nano Lett., 2011, 11: 1928

[15] MaruskaH. P., GhoshA. K.. Sol. Energy, 1978, 20: 443