Visible‐Light‐Driven Hydrogen Evolution Using Planarized Conjugated Polymer Photocatalysts

Abstract

Linear poly(p‐phenylene)s are modestly active UV photocatalysts for hydrogen production in the presence of a sacrificial electron donor. Introduction of planarized fluorene, carbazole, dibenzo[b,d]thiophene or dibenzo[b,d]thiophene sulfone units greatly enhances the H2 evolution rate. The most active dibenzo[b,d]thiophene sulfone co‐polymer has a UV photocatalytic activity that rivals TiO2, but is much more active under visible light. The dibenzo[b,d]thiophene sulfone co‐polymer has an apparent quantum yield of 2.3 % at 420 nm, as compared to 0.1 % for platinized commercial pristine carbon nitride.

Self‐Assembled PDINH Supramolecular System for Photocatalysis under Visible Light

“…Recently, Sprick' group found that increased exciton dissociation yields can be gained in polymers consisting of extended planarized units through decreasing the coulomb binding energy for dissociating electron-hole pairs. [45] Hence, integrating the above discussions, the strong cofacial π-π stacking of PDINH molecules along the long axis of its nanoplate would enable effective long-range band-like π-electron delocalization, [46] resulting in an enhancement of electronic coupling [39] and charge mobility. [47,48] Band-like electronic energy level structure similar to inorganic semiconductor due to orbital overlaps between PDINHmolecular units can be obtained by the self-assembled PDINH supramolecular system.…”

Trends and challenges for microporous polymers

“…Indeed, several linear or planarized, thus noncrosslinked and non-porous conjugated polymers have been recently shown to exhibit comparable or even better photocatalytic activities than their microporous network counterparts. 151,156,157 It is thus slightly surprising that so far no single paper on gas phase photocatalysis, e.g. CO 2 reduction has appeared as CMPs seem to be ideal candidates for such reactions.…”

Ionothermal Synthesis of Triazine–Heptazine‐Based Copolymers with Apparent Quantum Yields of 60 % at 420 nm for Solar Hydrogen Production from “Sea Water”

“…Recently,conjugated polymers,including conjugated microporous polymers (CMPs), [1][2][3][4] conjugated triazine frameworks (CTFs), [5][6][7][8] and carbon nitride based polymers, [9][10][11][12][13] have gathered particular interest as an ew generation of metalfree photocatalysts owing to their well-defined structure and promising ability for photocatalytic H 2 production. Among the known polymeric photocatalysts,polymeric carbon nitride (PCN), in our opinion, stands out in virtue of its wellconfigured band structures for water splitting and the excellent capacity to capture an abundance of visible photons.…”