The generation of radicals through photo-Fenton-like reactions demonstrates significant potential for remediating emerging organic contaminants (EOCs) in complex aqueous environments. However, the excitonic effect, induced by Coulomb interactions between photoexcited electrons and holes, reduces carrier utilization efficiency in these systems. In this study, we develop Cu single-atom-loaded covalent organic frameworks (Cu_SA/COFs) as models to modulate excitonic effects. Temperature-dependent photoluminescence and ultrafast transient absorption spectra reveal that incorporating acenaphthene units into the linker (Cu_SA/Ace-COF) significantly reduces exciton binding energy (E_b). This modification not only enhances peroxymonosulfate adsorption at Cu active sites but also facilitates rapid electron transfer and promotes selective hydroxyl radical generation. Compared to Cu_SA/Obq-COF (E_b = 25.6 meV), Cu_SA/Ace-COF (E_b = 12.2 meV) shows a 39.5-fold increase in the pseudo-first-order rate constant for sulfamethoxazole degradation (0.434 min⁻¹). This work provides insights into modulating excitonic behavior in single-atom catalysts via linker engineering for EOCs degradation.

Recently, the increasing concerns regarding environmental and energy-related issues due to the use of fossil fuels have triggered extensive research on sustainable electrochemical energy storage and conversion (EESC). In this case, covalent triazine frameworks (CTFs) possess a large surface area, tailorable conjugated structures, electron donating–accepting/conducting moieties, and excellent chemical and thermal stabilities. These merits make them leading candidates for EESC. However, their poor electrical conductivity impedes electron and ion conduction, leading to unsatisfactory electrochemical performances, which limit their commercial applications. Thus, to overcome these challenges, CTF-based nanocomposites and their derivatives such as heteroatom-doped porous carbons, which inherit most of the merits of pristine CTFs, lead to excellent performances in the field of EESC. In this review, initially, we briefly highlight the existing strategies for the synthesis of CTFs with application-targeted properties. Next, we review the contemporary progress of CTFs and their derivatives related to electrochemical energy storage (supercapacitors, alkali-ion batteries, lithium–sulfur batteries, etc.) and conversion (oxygen reduction/evolution reaction, hydrogen evolution reaction, carbon dioxide reduction reaction, etc.). Finally, we discuss perspectives on current challenges and recommendations for the further development of CTF-based nanomaterials in burgeoning EESC research.