Charge carrier dynamics in ZnO rods sensitized with CdTe quantum dots: photoelectrodes for water splitting

• Grant number: 14/08885-4
• Support Opportunities: Scholarships abroad - Research Internship - Doctorate
• Start date: August 31, 2014
• End date: August 06, 2015
• Field of knowledge: Physical Sciences and Mathematics - Chemistry - Physical-Chemistry
• Principal Investigator: Sergio Antonio Spinola Machado
• Grantee: Vanessa Nascimento dos Santos
• Supervisor: Alexander Cowan
• Host Institution: Instituto de Química de São Carlos (IQSC). Universidade de São Paulo (USP). São Carlos , SP, Brazil
• Institution abroad: University of Liverpool, England
• Associated to the scholarship: 11/20953-7 - Studies of semiconductor characteristics for CdS thin films modified by cadmium telluride nanoparticles (quantum dots), BP.DR

Abstract

This project proposes to study the dynamics of charge carriers in ZnO rods film sensitized with CdTe quantum dots employing transient absorption spectroscopy (TAS) technique. CdTe quantum dots are synthesized by a simple and reproducible method that provides high quality quantum dots and employs not so toxic and expensive reagents. CdTe quantum dots obtained will be evaluated by TEM, XRD, UV-vis absorption, DLS, fluorescence spectroscopy. For that, ZnO rods will be electrodeposited on indium tin oxide coated glass surface from an electrolytic bath containing 0.025 mol L-1 zinc nitrate (Zn(NO3)2) and hexamethylenetetramine (HMT) equimolar solutions. The obtained ZnO rods films will be evaluated by SEM, EDAX, XRD, Uv-vis absorption, optical microscopy, DRS and EIS. The CdTe quantum dots will be stabilized by a cap of alkanethiol (mercaptopropionic acid - AMP), which will allow the subsequent adsorption on the ZnO rods by a dipping procedure. The photoanode obtained by ZnO sensitized with CdTe quantum dots will be evaluated by TEM, EDAX, XRD, Uv-vis absorption, fluorescence spectroscopy, DRS and EIS. Electrical, kinetic and carge-transport interfacial properties will be evaluated by TAS measures. This project of research internship abroad was expected to run for one year from August 2014 and it will be conducted in the Stephenson Institute for Renewable Energy of University of Liverpool, in United Kingdom, under the supervision of Professor Alexander Cowan. (AU)