Bottom‐up Synthesis of Single‐Crystalline Poly (Triazine Imide) Nanosheets for Photocatalytic Overall Water Splitting

Abstract

Poly (triazine imide) (PTI/Li+Cl−), one of the crystalline versions of polymeric carbon nitrides, holds great promise for photocatalytic overall water splitting. In principle, the photocatalytic activity of PTI/Li+Cl− is closely related to the morphology, which could be reasonably tailored by the modulation of the polycondensation process. Herein, we demonstrate that the hexagonal prisms of PTI/Li+Cl− could be converted to hexagonal nanosheets by adjusting the binary eutectic salts from LiCl/KCl or NaCl/LiCl to ternary LiCl/KCl/NaCl. Results reveal that the extension of in‐plane conjugation is preferred, when the polymerisation was performed in the presence of ternary eutectic salts. The hexagonal nanosheets bears longer lifetimes of charge carriers than that of hexagonal prisms due to lower intensity of structure defects and shorter hopping distance of charge carriers along the stacking direction of triazine nanosheets. The optimized hexagonal nanosheets exhibits a record apparent quantum yield value of 25 % (λ=365 nm) for solar hydrogen production by one‐step excitation overall water splitting.

Cyano-modified poly(triazine imide) with extended π-conjugation for photocatalytic biological cofactor regeneration

“…The vibrations located at 3200 cm −1 are mainly caused by the surface amino vibrations. 5,39 Meanwhile, the D-PTI-350 sample exhibits a typical cyano vibrational peak at 2165 cm −1 , which is consistent with the XPS analysis results, further confirming the successful incorporation of the -CN functional group in PTI (Fig. 3d and S7 and S8 †).…”

“…Meanwhile, the biocatalysis system using enzymes as catalysts has many advantages such as high efficiency, greenness, specificity, and selectivity. [1][2][3][4][5] Currently, photo-enzymatic catalysis seamlessly integrates the light absorption capabilities of photocatalysis with the benefits of enzymatic catalysis, including gentle reaction conditions, high activity, and exceptional selectivity. [6][7][8] As a result, it has emerged as a leading innovation in the realm of artificial photosynthesis.…”

“…In contrast to PCN, crystalline poly(triazine imide) (PTI) and poly(heptazine imide) (PHI) exhibit a more organized atomic structure and planar formation, leading to the extension of the π-conjugated plane. 5,28,29 This may facilitate π-π stacking interactions with NADH, enhancing its binding and participation in enzymatic reactions. In addition, due to the ordered arrangement of atoms in crystalline carbon nitride, it exhibits higher conductivity and facilitates charge transfer properties.…”