Kai. A. I. Zhang

Inspired by the direct charge transfer in the natural photosystems, herein, we design covalent triazine frameworks (CTFs) with direct electron transfer by constructing the minimal amount of –donor–acceptor 1–acceptor 2– type moieties in the CTF backbone for photocatalytic hydrogen evolution. By introducing only 0.75% of the acceptor 2, the as-prepared CTF exhibited an enhanced hydrogen evolution rate of 3215 μmol g⁻¹ h⁻¹.

Conjugated polymers (CPs) have garnered attention for their tailorable structural properties, particularly in the context of efficient photosynthetic hydrogen peroxide (H ₂ O ₂ ) production.

Conjugated microporous polymers (CMPs) exhibiting semiconductor properties have been widely employed as heterogeneous photocatalysts. Photogenerated charge carrier separation and transfer are crucial factors influencing the performance of such photocatalysts. Typically, the electron/acceptor units linked by carbon–carbon single bonds tend to form larger dihedral angles due to steric hindrance, thus inhibiting the transport of charge carriers, leading to recombination of photogenerated electro-hole pairs and consequently limiting the photocatalytic performance of the material. Based on this, we designed two CMPs, one with a planar structure, dibenzo[g,p]chrysene (DBC), and the other with a non-planar structure, tetraphenylethylene (TPE), to investigate the influence of planarity on the catalytic performance of the materials. Theoretical simulation results reveal that CMP-DBC, with its planar structure, has a significantly smaller dihedral angle for the electron donor (18.4°) compared to CMP-TPE (47.8°). According to calculations from temperature-dependent fluorescence spectroscopy, the exciton binding energy of the former (108 meV) is also smaller than that of the latter (126 meV). In the photocatalytic dehalogenation reaction, CMP-DBC achieves nearly 100% halide product yield, far surpassing the 60% yield of CMP-TPE. Both theoretical and experimental results indicate that CMP-DBC, with its smaller donor–acceptor dihedral angle, facilitates charge carrier migration, effectively suppressing rapid radiative recombination, and thus exhibits superior photocatalytic performance.

The copolymerization of photocatalytic moieties into a polymeric material has emerged as a new development platform for heterogeneous photocatalysts. Incorporating small molecule photocatalysts into polymeric structures has created a new class of heterogeneous photocatalysts. However, the effect and interaction of the comonomer on the photocatalyst have been mostly ignored and little is known about the influence of classical polymer composition on photocatalytic efficiency. Here a vinyl functionalized benzothiadiazole photocatalyst was copolymerized with three dramatically different monomers, methyl methacrylate, styrene, and acrylonitrile, via free radical polymerization, to investigate the effect of the comonomer choice on the photophysical properties and photocatalytic efficiency.

Design strategies for efficient π-conjugated polymer-based photocatalysts, and the progress achieved in light-driven chemical transformations using them.

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.