TiO2/ZnO core/shell nano-heterostructure arrays as photo-electrodes with enhanced visible light photoelectrochemical performance


Autoria(s): Sarkar, Ayan; Singh, Ashutosh K; Khan, Gobinda Gopal; Sarkar, Debasish; Mandal, Kalyan
Data(s)

2014

Resumo

The present article reports a facile method for preparing the vertically-aligned 1D arrays of a new type of type II n-n TiO2/ZnO core/shell nano-heterostructures by growing the nano-shell of ZnO on the electrochemically fabricated TiO2 nanotubes core for visible light driven photoelectrochemical applications. The strong interfacial interaction at the type II heterojunction leads to an effective interfacial charge separation and charge transport. The presence of various defects such as surface states, interface states and other defects in the nano-heterostructure enable it for improved visible light photoelectrochemical performance. The presence of such defects has also been confirmed by the UV-vis absorption, cathodoluminescence, and crystallographic studies. The TiO2/ZnO core/shell nano-heterostructures exhibit strong green luminescence due to the defect transitions. The TiO2/ZnO core/shell nano-heterostructures photo-electrode show significant enhancement of visible light absorption and it provides a photocurrent density of 0.7 mA cm(-2) at 1 V vs. Ag/AgCl, which is almost 2.7 times that of the TiO2/ZnO core/shell nano-heterostructures under dark conditions. The electrochemical impedance spectroscopy results demonstrate that the substantially improved photoelectrochemical and photo-switching performance of the nano-heterostructures photo-anode is because of the enhancement of interfacial charge transfer and the increase in the charge carrier density caused by the incorporation of the ZnO nano-shell on TiO2 nanotube core.

Formato

application/pdf

Identificador

http://eprints.iisc.ernet.in/50550/1/rsc_adv_4-98_55629_2014.pdf

Sarkar, Ayan and Singh, Ashutosh K and Khan, Gobinda Gopal and Sarkar, Debasish and Mandal, Kalyan (2014) TiO2/ZnO core/shell nano-heterostructure arrays as photo-electrodes with enhanced visible light photoelectrochemical performance. In: RSC ADVANCES, 4 (98). pp. 55629-55634.

Publicador

ROYAL SOC CHEMISTRY

Relação

http://dx.doi.org/ 10.1039/c4ra09456e

http://eprints.iisc.ernet.in/50550/

Palavras-Chave #Solid State & Structural Chemistry Unit
Tipo

Journal Article

PeerReviewed