Yttrium doping enhances the photoelectrochemical water splitting performance of ZnO nanorod array films

• Published in: Journal of alloys and compounds Vol. 896; p. 163144
• Main Authors: Wei, Yuling, Wang, Leshuang, Chen, Changlong
• Format: Journal Article
• Language: English
• Published: Lausanne Elsevier B.V 10.03.2022; Elsevier BV
• Subjects: Arrays; Carrier lifetime; Crystal structure; Current carriers; Donors (electronic); Doping; Electromagnetic absorption; Electronic structure; Fluorine; Nanorods; Photoanode; Photoelectric effect; Photoelectric emission; Photoelectrochemical; Substrates; Tin oxides; Water oxidation; Water splitting; Wurtzite; Zinc oxide; Zinc oxide; Water splitting; Photoanode; Water oxidation; Photoelectrochemical; Doping
• ISSN: 0925-8388; 1873-4669
• DOI: 10.1016/j.jallcom.2021.163144

Yttrium doped ZnO nanorod array films are hydrothermally grown on fluorine doped tin oxide substrates. The yttrium doped ZnO samples maintain the same wurtzite crystal structure and nanorod morphology as those of the undoped samples, but they shows much enhanced photoelectrochemical water splitting performance. It is found that yttrium doping not only enhances the light absorption of the ZnO, but also provides more donors for ZnO and thereby enhances the conductivity of the ZnO nanorods. Moreover, the charge carrier lifetime of ZnO becomes longer after yttrium doping. These changes in the electronic structure of ZnO caused by yttrium doping significantly improve its photoelectrochemical performance. Under AM 1.5 G illumination at 100 mW/cm2 and a potential of 1.23 V vs. reversible hydrogen electrode, the yttrium doped ZnO samples can get a photocurrent density of ~ 0.50 mA/cm2, while the undoped ZnO samples only show photocurrent densities of ~ 0.30 mA/cm2 under the same conditions. Considering that ZnO has advantages of low cost, environmental friendliness and simple and mild preparation process, it is expected that the yttrium doped ZnO nanorod array films will provide valuable platforms for a wide photocatalytic applications, not just limited to photoelectrochemical water splitting. Y doped ZnO nanorod arrays grown on FTO substrate directly using as photoanode for photoelectrochemical water splitting reveal much enhanced performance due to the electronic structure changing of the ZnO caused by the introduction of dopant Y. [Display omitted] •Y doping reduces the charge transfer resistance of ZnO.•Y doping reduces the resistance (RCT) of holes transferred from ZnO to the electrolyte.•Y doping increases the carrier lifetime of ZnO nanorod arrays.•Dopant Y and nanorod configuration synergistically enhances the absorption of ZnO to the incident light.