Enhancing piezocatalysis for chemical transformations using cocatalysed ferroelectrics

This thesis presents a comprehensive investigation into the piezocatalytic capabilities of barium titanate (BTO), both as a bare material and in combination with metal and metal oxide cocatalysts, for renewable energy production and environmental remediation. The research emphasises the degradation of organic dye pollutants and the enhancement of water splitting for hydrogen production. The degradation of Rhodamine B (RhB) using BTO nanoparticles is explored with the efficiency of the process depending on variables such as calcination temperature, structural properties, and the influence of atmosphere and agitation. The findings reveal the crucial role of oxygen in the degradation process and identify optimal conditions for catalyst loading and stirring parameters, positioning BTO as a viable candidate for environmental remediation. The application of BTO is extended to hydrogen production by mixing it with metallic Pt nanoparticles through a simple solid-state synthesis method. The interaction between BTO and Pt highlights a significant enhancement in hydrogen evolution rate, marking a substantial increase compared to pristine BTO. The research highlights the importance of BTO's ferroelectric properties and their contribution to improved catalytic activity. The formation of hydrogen peroxide as a byproduct presents both a challenge and an opportunity for future research aimed at optimising the selectivity and efficiency of piezocatalytic reactions. Furthermore, the investigation delves into BTO-metal oxide composites and their piezocatalytic application for dye degradation. The structural properties of various BTOmetal oxide heterostructures are analysed, with BTO-CuO and BTO-NiO heterojunctions leading to an enhanced piezocatalytic activity compared to the other composites examined. The potential for generating reactive oxygen species (ROS) is discussed in relation to energy band theory, which is useful for understanding the mechanisms occurring at heterojunction interfaces. Collectively, the thesis demonstrates the comprehensive understanding of BTO as a piezocatalyst, and it confirms the role of cocatalysts in increasing BTO's piezocatalytic activity for dye degradation and hydrogen production, whether for environmental or in renewable energy applications. Overall, the insights and methodologies offered in this work have significant implications for designing and optimising materials for environmental and energy applications in pollution reduction, and the harnessing of renewable energy. This detailed abstract encapsulates the core advancements of the thesis, bridging multiple investigations that showcases both the challenges and breakthroughs encountered throughout the research journey. It offers a comprehensive view of the scholarly contributions made in the domain of piezocatalysis, paving the way for future innovations in the emerging field.