6 research outputs found
Modulation of the Perylene Polyimide Crystalline Structure and Oxygen Vacancy Contents for Enhanced Photocatalytic Performance
Perylene
polyimide networks are currently one of the most promising
metal-free photocatalysts due to their excellent electrical and optical
tunability. However, the disordered aggregation state structure in
perylene polyimide resulting from the traditional imidization process
is detrimental to the separation and migration of the photogenerated
charges, which in turn greatly hampers its photocatalytic activity.
Herein, we report a facile approach to construct highly crystalline
(∼98%) perylene polyimide photocatalysts via cascade reactions
involving the assembly of perylenetetracarboxylic acid-melamine monomer
salt crystals (PTA-MA), followed by solid-state imidization of the
PTA-MA monomer salt. Meanwhile, oxygen vacancies (OVs) were introduced
during the polycondensation of the PTA-MA monomer salts. By adjusting
the polycondensation temperature, perylene polyimide photocatalysts
(PTA-MA-Tn) with varying crystallinity and contents of OVs were obtained.
Benefiting from its highly ordered structure and optimized OVs content,
the as-prepared perylene polyimide photocatalyst (PTA-MA-200) obtains
a suitable crystal structure and excellent photon-to-electron conversion
efficiency and exhibits exceptional photoactivity in the photocatalytic
valorization of benzylamines into imines. An approximately 10-fold
increase in the rate of benzylamine photocatalytic conversion was
observed in comparison to PTA. This study paves the way for the development
of highly crystalline polyimide photocatalysts and has the potential
to enhance the understanding of the structure–activity correlation
in the context of applying perylene polyimide photocatalysts in practical
scenarios