CARBON DIOXIDE ACTIVATION AND SUBSEQUENT REDUCTION TO VALUE-ADDED CHEMICALS AND FUELS ON GRAPHITIC CARBON NITRIDE SURFACES

Abstract

The global imperative to mitigate climate change and reduce our dependence on fossil fuels has never been more urgent. This thesis addresses this critical challenge by exploring innovative solutions for sustainable energy production, with a particular focus on the photon-assisted reduction of carbon dioxide (CO2) into valuable chemicals and fuels. At the heart of this research lies the exploration of graphitic carbon nitride (g-C3N4) as a promising photocatalyst for CO2 reduction. Through a series of carefully designed experiments and in-depth analyses, this work delves into the intricate relationships between material synthesis, structural properties, and photocatalytic performance. The thesis begins with a comprehensive review of the fundamental principles and current state of the art in photon-assisted CO2 conversion. It then progresses through a systematic investigation of various aspects of g-C3N4 photocatalysts, including the impact of precursor selection, the role of crucible materials in synthesis, and innovative approaches such as ionothermal and supramolecular-assisted eutectic synthesis methods. A key strength of this research lies in its multifaceted analytical approach. By employing a wide array of advanced characterization techniques and introducing novel parameters such as normalized surface concentration (NSC%) and light absorption efficiency per unit surface area (DP/SA), this work provides unprecedented insights into the structure-property-performance relationships of g-C3N4 materials. Moreover, this thesis challenges conventional wisdom in the field of photon-assisted catalysis. It questions the adequacy of traditional efficiency measures and proposes new approaches for assessing the true activity of photocatalytic systems. The work emphasizes the critical importance of considering both catalyst characteristics and effective illumination in designing efficient photon-assisted catalytic processes. The findings presented herein not only contribute to the fundamental understanding of g-C3N4 photocatalysts but also offer practical guidelines for the rational design of more efficient materials for CO2 reduction. Furthermore, this research opens new avenues for exploration in the field of solar fuel production, particularly in the areas of material synthesis and catalytic system design. As we stand at the crossroads of environmental sustainability and energy security, the insights and methodologies developed in this thesis aim to accelerate progress towards viable solutions for CO2 utilization and renewable energy production. It is my hope that this work will serve as a valuable resource for researchers and practitioners in the field, inspiring further innovations in sustainable energy technologies. This thesis represents not just the culmination of years of dedicated research, but also a call to action for the scientific community to reevaluate and refine our approaches to photon-assisted catalysis. As we continue to face the challenges of climate change, the pursuit of efficient and sustainable energy solutions remains more critical than ever.