The roles of β-diketones and their derivatives in the design of photocatalysts

Organic ligands play pivotal roles in the synthesis and modification of photocatalysts. Small molecular diketones, exemplified by acetylacetone (acac), are a promising class of ligands. Nevertheless, a comprehensive review of their roles in photocatalysis has not yet been conducted. This gap hinders the rational design and application of photocatalysts by using diketones as functional ligands. It is therefore imperative to provide a comprehensive examination of this topic. This review critically summarizes the utilization of acac in photocatalysis from four aspects: the chemical nature and reactivity of acac, the roles of acac in the synthesis and modification of photocatalysts (especially the well-known TiO₂), its influence on the photocatalytic processes, and the existing challenges and future prospects for acac-mediated photocatalysis. By providing a critical analysis of the established applications of acac in photocatalysis, we aim to inspire further advancements in the field rooted in fundamental theoretical principles.