Floatable photocatalysts: Design principles and application advances

The photocatalysis technology is known for its cleanliness, safety, ease of operation, and low pollution levels. However, traditional photocatalysts still have certain limitations: (1) the mechanism of charge generation and transfer within the photocatalyst particles remains unclear; (2) serious agglomeration leads to low catalytic efficiency, poor catalytic effects, weak light absorption ability, and difficulty in reuse. In contrast, floatable catalysts have been extensively studied over the past decade due to their exceptional properties, such as stable structure, easy recovery, high efficiency, etc. The present review paper begins by providing a comprehensive review of floatable photocatalysts, followed by an analysis and summary of their photocatalytic systems ranging from macro-design structure to micro-nano structure. Additionally, this paper introduces novel design principles and methods for floatable photocatalysts (for example, double-layer structure and hot-cold-end design). Furthermore, recent advancements in floatable photocatalysts are discussed through case studies in areas such as photocatalytic synthesis, degradation, power generation, and hydrogen production. The high recovery rate, high activity, and high stability of floating photocatalysts significantly impact the field of photocatalysis. This review aims to provide guidance for early researchers while offering theoretical support for future preparation and optimization efforts related to practical photocatalysts.