Organic polymers
with conjugated architectures have been
widely exploited as photocatalyst materials for hydrogen generation.
However, it is still an enormous challenge to develop photocatalysts
with high hydrogen generation activity under natural sunlight, which
is pretty significant for practical applications. Herein, two conjugated
microporous polymer photocatalysts with definite D−π–A
structures are designed and prepared using dibenzo[g,p]chrysene or pyrene with planar conjugated architecture
as electron donors, thiophene as a π-spacer, and dibenzo[b,d]thiophene-S,S-dioxide as an electron acceptor. Benefiting from the efficient
separation of light-generated electrons/holes due to the definite
D−π–A structure and the broad light absorption
range, the bare polymer Py-TP-BTDO could deliver a high photocatalytic
hydrogen evolution rate (HER) of 115.03 mmol h–1 g–1 upon exposure to visible light (λ >
420 nm). Impressively, the outdoor photocatalytic experiment reveals
that abundant and continuous hydrogen bubbles could be produced fast
and visually observed under natural sunlight by the Py-TP-BTDO polymer
film with a large active area of 120 cm2. A water-drainage
experiment further demonstrates that 1224 mL of hydrogen gas could
be produced by 25 mg of a polymer photocatalyst with 3 wt % Pt cocatalyst
under natural sunlight in 7 h, corresponding to a high HER of 312.24
mmol h–1 g–1, which represents
the state of the art of organic photocatalyst materials to date. The
high photocatalytic activity under natural sunlight suggests the potential
of the developed Py-TP-BTDO polymer photocatalyst in the practical
applications for photocatalytic hydrogen production.