Photocatalytic Hydrogen Evolution from Water Using Fluorene and Dibenzothiophene Sulfone-Conjugated Microporous and Linear Polymers

Abstract

Three series of conjugated microporous polymers (CMPs) were studied as photocatalysts for hydrogen production from water using a sacrificial hole scavenger. In all cases, dibenzo[b,d]thiophene sulfone polymers outperformed their fluorene analogues. A porous network, S-CMP3, showed the highest hydrogen evolution rates of 6076 μmol h −1 g −1 (λ > 295 nm) and 3106 μmol h −1 g −1 (λ > 420 nm), with an external quantum efficiency of 13.2% at 420 nm. S-CMP3 outperforms its linear structural analogue, P35, whereas in other cases, nonporous linear polymers are superior to equivalent porous networks. This suggests that microporosity might be beneficial for sacrificial photocatalytic hydrogen evolution, if suitable linkers are used that do not limit charge transport and the material can be wetted by water as studied here by water sorption and quasi-elastic neutron scattering.

Bisulfone‐Functionalized Organic Polymer Photocatalysts for High‐Performance Hydrogen Evolution

“…It has been demonstrated that the Pd residue in the Pd‐catalyzed polymers can contribute to the photocatalytic activity . No apparent Pd signal for both polymers was detected by energy‐dispersive X‐ray (EDX) measurements (Figure S5 in the Supporting Information), and the content of Pd residue in the polymers measured by inductively coupled plasma (ICP)‐MS is very low (Figure S6 in the Supporting Information).…”

Recent Advances in Visible‐Light‐Driven Hydrogen Evolution from Water using Polymer Photocatalysts

“…Cooper and coworkers have reported several pyrene‐ and spirobifluorene‐based CMPs with tunable physical properties that were highly efficient photocatalysts for H 2 evolution under visible light in aqueous solution . Later, Sprick and coworkers reported the syntheses of three series of CMPs and studied their photocatalytic H 2 evolution from water using a sacrificial hole scavenger . Dibenzo[ b,d ]thiophene sulfone polymers performed better with fluorene building blocks.…”

“…[42,43] Later, Sprick and coworkers reported the syntheses of three series of CMPs and studied their photocatalytic H 2 evolution from water using a sacrificial hole scavenger. [44] Dibenzo [b,d]thiophene sulfone polymers performed better with fluorene building blocks. In particular, SCMP3 exhibited a high HER of 3,106 μmol h À 1 g À 1 with an outstanding AQY of 13.2 % at 420 nm, which is very 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 high compared to those of CP-or CMP-based photocatalysts (see Tables 1 and 2).…”

Aromatic polymers made by reductive polydehalogenation of oligocyclic monomers as conjugated polymers of intrinsic microporosity (C-PIMs)

“…25,26 Several folding motifs, including on-chain spirobifluorene 27,28 /spirobiindane, 29 binaphthyl, 30 triptycene 31 or norbornyl bis(benzocyclobutene) 32 units, have been introduced to give a shape-persistent folding of rigid-rod type polycyclic segments of linear polymer chains that pack into bulk materials with a persistent free volume. 33 Also several conjugated polymers (CPs) with bulky main chain substituents, including poly(trimethylsilylacetylene)s 34 or poly(diphenylacetylene)s 35 and CPs containing 1,3-phenylene units [36][37][38][39] show a permanent microporosity with S BET surface areas up to 730 m 2 g −1 (so-called conjugated PIMs-C-PIMs). Based on these concepts we have tested if the incorporation of strongly folded tetrabenzoheptafulvalene (TBHF) or twisted bifluorenylidene motifs into the linear, polycyclic homopolymers P55, PDIN, P77 and P57 as well as the copolymer P55/77 also induces a permanent microporosity.…”