Experimental and First Principles Theoretical Studies on Nanostructured Bilayered Semiconductor Systems in Photoelectrochemical Splitting of Water

Abstract

The aim of the present study was to developed a theoretical model for heterojunction systems using DFT calculations and validating the same by experimentally preparing heterojunction thin films and then performing PEC studies. newlineThe thesis has been categorized into five chapters. First chapter introduction details out the current research topic with aims and objectives along with simulations methods used for theoretical calculations and various theories related to PEC generation of hydrogen including the basics of semiconductors and their interaction with the electrolyte. Chapter 2 presents the literature review on the present status of research on the use of layered structures for its application in PEC cell for water splitting. Details of the experimental methods used to synthesize, modify and characterize the prepared materials have been presented in chapter 3. Results and discussion on nanostructured heterojunction thin films studied in the thesis viz, Cu2O/BaZrO3, SrTiO3/Cu2O, Cu2O/SrTiO3, BaTiO3/Cu2O, CeO2/Cu2O, and Ti-Fe2O3/Cu2O have been presented in Chapter 4. Finally conclusions of the thesis and recommendations for further work are presented in Chapter 5. newlineAll pristine and heterojunction thin films were deposited on ITO (Sn: In2O3) conducting glass substrate by sol-gel spin-coating and spray pyrolysis method. Heterojunction thin film samples were prepared with various combinations and thicknesses and their effect on PEC performance was also explored. All samples were converted into photoelectrodes and investigated for their photoresponse in PEC cell. Experimental details included characterization for their structural, morphological and optical properties by X- ray diffractometer (XRD), UV-Visible spectrophotometer, Scanning electron microscope (SEM), Transmission electron microscope (TEM) and X-ray Photoelectron Spectroscope (XPS) studies respectively to analyze their PEC response. newline newline