Powar Niket Suresh. (2024). Designing and understanding disordered photocatalyst active sites for solar-light-driven CO2 conversion to hydrocarbon fuel production. doi: 10.22677/THESIS.200000802435
Type
Thesis
Description
Amorphous photocatalyst, CO2 reduction, heterostructure, photocatalyst
Table Of Contents
Graphical abstract 1 Chapter 1 Introduction 2 1.1 FOSSIL FUEL DEPENDENCY 2 1.2 RECYCLING CO2 IN TERMS OF PHOTOREDUCTION 3 1.3 CURRENT STATE-OF-ART FOR CO2 PHOTOREDUCTION 4 1.4 AMORPHOUS SEMICONDUCTOR AS PHOTOCATALYST 6 1.5 ENGINEERING THE AMORPHOUS PHOTOCATALYST FOR CO2 REDUCTION 7 1.6 LIGHT ABSORPTION IN AMORPHOUS PHOTOCATALYST 7 1.7 ADSORPTION, HAPTICITY () AND PRODUCT SELECTIVITY OF CO2 MOLECULES 9 1.8 VARIABLE COORDINATION NUMBERS 13 1.9 ROADMAP OF THESIS 15 1.10 REFERENCES 17
Chapter 3 Enhancement of visible-light-driven gas-phase photocatalytic CO2 reduction by dual active sites of Ti3+ and In3+ on In2TiO5 40 3.1 INTRODUCTION 40 3.2 EXPERIMENTAL SECTION 42 3.2.1 Synthesis of In2TiO5 42 3.2.2 Synthesis of In2TiO5/MoSe2 42 3.2.3 Photocatalytic Activity 42 3.2.4 Synthesis of TiO2 nanoparticles 43 3.2.5 Synthesis of In2O3 Nanoparticle 43 3.2.6 Photoresponsive measurement 43 3.2.7 Electrochemical analysis 43 3.2.8 NMR Sample Analysis 43 3.2.9 DRIFTS Experimental Details 44 3.2.10 XAFS Experimental Details 44 3.3 MATERIALS CHARACTERISATION 44 3.4 THEORETICAL SIMULATION 45 3.5 RESULTS AND DISCUSSION 46 3.5.1 Mechanism of formation of In2TiO5 46 3.5.2 Optical and charge transfer properties 46 3.5.3 Surface composition, structural studies and morphology analysis 48 3.5.4 XAFS analysis of In2TiO5/MoSe2 54 3.5.5 Photocatalytic activity 58 3.5.6 Reaction mechanism for CO2 photoreduction 62 3.5.7 Diffuse Reflectance Infrared Fourier Transform Spectroscopy (DRIFTS) 63 3.5.8 Density functional theory (DFT) simulation 65 3.6 CONCLUSION 67 3.7 REFERENCES 73
Graphical abstract 76 Chapter 4 Insights into Ti3+/Ti4+ dynamics: Exploring CO2 photoreduction pathways in gas-solid phase 77 4.1 INTRODUCTION 77 4.2 EXPERIMENTAL SECTION 79 4.2.1 Synthesis of C-TiO2/CdSe 79 4.2.2 Synthesis of A-TiO2/CdSe 79 4.2.3 Synthesis of TiO2 nanoparticles 80 4.2.4 Synthesis of CdSe Nanocrystals 80 4.2.5 Photoresponsive measurement 80 4.2.6 Electrochemical analysis 81 4.2.7 Materials Characterisation 81 4.2.8 DRIFTS Experimental Details 81 4.2.9 XAFS Experimental Details 82 4.2.10 Photocatalyst regeneration process 83 4.2.11 Computational Details 83 4.2.12 Density functional simulation 84 4.3 RESULTS AND DISCUSSION: 85 4.3.1 Method Development 85 4.3.2 Optical and charge carrier properties 85 4.3.3 Structural and morphological characterisations 87 4.3.4 Sunlight─driven photocatalytic CO2 reduction 97 4.3.5 Multi─solar photon flux─driven photocatalytic CO2 reduction 99 4.3.6 Insights into the photocatalytic CO2 reduction mechanism 100 4.4 CONCLUSION 115 4.5 REFERENCES 121
Graphical abstract 127 Chapter 5 Harnessing mixed valency of Ti3+/Ti4+ and non-stoichiometric Ag2S nanowire design in a direct Z-scheme for enhanced CH4 production 128 5.1 INTRODUCTION 128 5.2 EXPERIMENTAL SECTION 129 5.2.1 Synthesis of TiO2 nanoparticles 129 5.2.2 Synthesis of non-stoichiometric Ag2S nanowires (Ag2S NWs) 130 5.2.3 Synthesis of A-TiO2/ Ag2S NWs 130 5.3 RESULTS AND DISCUSSION 131 5.3.1 Structural and morphological analysis 131 5.3.2 Coordination environment analysis 137 5.3.3 Photocatalytic CO2 reduction 140 5.3.3.1 Solar-driven photocatalytic CO2 reduction 140 5.3.3.2 Multiphoton flux-driven CO2 photoreduction 142 5.3.4 Insights of active site determination of CO2 photoreduction 144 5.3.5 Charge carrier and reaction mechanism dynamics of CO2 photoreduction 148 5.3.5.1 Charge carrier and optical properties 148 5.3.5.2 Reaction mechanism dynamics of CO2 photoreduction. 150 5.3.6 Density functional analysis on Ag2S NWs surface 156 5.4 CONCLUSION 159 5.5 REFERENCES 165
