Sonochemistry and sonocatalysis: current progress, existing limitations, and future opportunities in green and sustainable chemistry

Sonocatalysis is a specialised field within sonochemistry that leverages the interaction between ultrasound and solid catalysts to enhance the rate and selectivity of chemical reactions. As a non-traditional catalytic activation method, sonocatalysis can profoundly modify reaction mechanisms and unlock novel activation pathways that are not typically accessible through standard catalysis. This unique approach offers new opportunities for driving reactions under milder conditions while potentially improving selectivity and efficiency. This review highlights the recent progress of sonocatalytic applications in green chemistry and their contribution to the United Nations' Sustainable Development Goals (SDGs), including environmental remediation, sonotherapy, and biomass conversion. In these applications, we explore the underlying sonocatalytic mechanisms and the interaction between solid catalysts and ultrasound, which drive the enhanced reactivity. A key feature of this manuscript is its comprehensive analysis of the primary technical challenges in sonocatalysis, specifically its low energy efficiency and the complexity of reaction control. To address these hurdles, we examine various effective strategies, such as the incorporation of nanostructured catalytic cavitation agents and the design of advanced microfluidic sonoreactors. These innovations improve energy transfer, control bubble dynamics, and enhance catalytic activity under ultrasound. Furthermore, we implement molecular modelling to gain fundamental insights into the mechanisms fundamental to the effectiveness of sonocatalysts. This approach provides a deeper understanding of how nanostructured catalysts interact with ultrasonic fields, guiding the design of next-generation catalytic materials. The integration of nanostructured catalytic cavitation agents, microfluidic reactor technologies, and computational molecular modelling forms a trilateral synergistic platform that unlocks new potential in sonocatalysis. This multidisciplinary framework paves the way for significant advancements in green and sustainable chemistry, offering innovative solutions to global challenges in energy, health, and environmental sustainability.