Synthesis of Bismuth Ferrite for Photoelectrochemical Water Splitting

Abstract

Synthesis of Bismuth Ferrite for Photoelectrochemical Water Splitting by Fagr Albagle Converting solar energy to chemical fuels is one of the alternative solutions to address the sustainable energy challenges in the world. This can be achieved through photocatalytic conversion of solar energy to chemical energy stored in hydrogen (H2) via photoelectrochemical water splitting. It still remains a significant challenge in developing semiconductors as photoelectrodes for photoelectrochemical water oxidation. The objective of this project is to develop and synthesize a semiconductor-based material for photoelectrochemical water splitting. A perovskite bismuth ferrite oxide (BiFeO3) thin film has been synthesized and deposited onto a fluorine-doped tin oxide (FTO) coated glass substrate by the sol-gel process. The thickness of thin film has been tuned by applying different spin coating cycles. The photoelectrochemical properties of the bismuth ferrite oxide (BFO) film have been investigated. The BFO photoanode exhibits the n-type behavior with a flat band potential of 0.36 V versus the reversible hydrogen electrode (RHE). The BFO film possesses a band gap about 2.0 eV, which is favorable for photoelectrochemical water splitting. Among the three BFO thin film samples prepared, five spin cycles achieved the highest photocurrent. The results show that the BFO film photoanode is very stable and capable of generating hydrogen through photoelectrochemical water splitting. However, an improvement in the photocurrent needs to be studied through the use of co-catalyst and metal transition doping. The knowledge obtained from our findings can be used for development of metal oxide based materials for solar fuel generation. TABLE OF CONTENTS ABSTRACT II ACKNOWLEDGMENTS III TABLE OF CONTENTS IV TABLES OF FIGURES VI 1. INTRODUCTION 1.1. BACKGROUND 1.2. MOTIVATION AND OBJECTIVES 1.3. SIGNIFICANCE 2. LITERATURE REVIEW 2.1. INTRODUCTION 2.2. GENERAL INTRODUCTION TO HYDROGEN FUEL GENERATION 2.2.1. HYDROGEN FUEL PRODUCTION FROM FOSSIL FUELS 2.2.2. HYDROGEN FUEL PRODUCTION FROM SOLAR ENERGY 2.3. PRINCIPLE OF PHOTOCATALYTIC WATER SPLITTING 2.3.1. PROCESS OF PHOTOCATALYTIC WATER SPLITTING 2.3.2. FUNDAMENTAL THEORY OF PHOTOCATALYTIC WATER SPLITTING 2.4. PEROVSKITE METAL OXIDE MATERIALS AS PHOTOCATALYSTS 2.4.1. STRUCTURE OF PEROVSKITE METAL OXIDE 2.4.2. PEROVSKITE MATERIALS IN PHOTOCATALYSIS 2.5. PEROVSKITE BISMUTH FERRITE OXIDE 2.5.1. STRUCTURE OF BISMUTH FERRITE OXIDE 2.5.2. SYNTHESIS OF BISMUTH FERRITE OXIDE BY DIFFERENT ROUTES 3. BISMUTH FERRITE OXIDE THIN FILM SYNTHESIS AND CHARACTERIZATION 3.1 INTRODUCTION 3.2 EXPERIMENTAL SECTION 3.2.1 PREPARATION OF BIFEO3 PRECURSOR 3.2.2 DEPOSITION OF BIFEO3 THIN FILM iv 3.3 CHARACTERIZATION OF THE BFO THIN FILM 3.4 RESULTS AND DISCUSSION 3.4.1 MORPHOLOGY AND CRYSTAL STRUCTURE OF THE BIFEO3 THIN FILM 3.4.3 CHEMICAL STATE AND ELECTRONIC STRUCTURE OF BIFEO3 FILMS 3.4.4 OPTICAL ABSORPTION OF BIFEO3 THIN FILM 4. PHOTOELECTROCHEMICAL TESTING OF BISMUTH FERRITE OXIDE THIN FILMS 38

Bi site doped Ferroelectric BiFe0.95Mn0.05O3 Nanoparticles for Hydrogen Evolution Reaction

“…As a consequence, BFO has a very high ferroelectric Curie transition temperature (T C ) around 830 °C with a large ferroelectric remnant polarization (P r ) being around 50-150 μCcm À 2 for high quality BFO thin films and 40 μCcm À 2 for Bulk BFO ceramics, along the polar axis. [24][25][26][27] In literature the photoelectrochemical activity of BFO NPs is discussed [28][29][30] however, the electrocatalytic activity of BFO NPs towards HER is less studied, especially in terms of doping influence on BFO's HER activity.…”