Photocatalytic hydrogen production from water offers an abundant, clean fuel source, but it is challenging to produce photocatalysts that use the solar spectrum effectively. Many hydrogen-evolving photocatalysts are active in the ultraviolet range, but ultraviolet light accounts for only 3% of the energy available in the solar spectrum at ground level. Solid-state crystalline photocatalysts have light absorption profiles that are a discrete function of their crystalline phase and that are not always tunable. Here, we prepare a series of amorphous, microporous organic polymers with exquisite synthetic control over the optical gap in the range 1.94–2.95 eV. Specific monomer compositions give polymers that are robust and effective photocatalysts for the evolution of hydrogen from water in the presence of a sacrificial electron donor, without the apparent need for an added metal cocatalyst. Remarkably, unlike other organic systems, the best performing polymer is only photoactive under visible rather than ultraviolet irradiation.

Microporous organic polymers have been synthesised from aniline using Friedel–Crafts alkylation. Networks synthesised solely from aniline were non-porous to nitrogen. However, co-polymerisation with benzene resulted in networks with apparent Brunauaer-Emmett-Teller (BET) surface areas up to 1100 m² g⁻¹. Increased aniline content in the hyper-crosslinked networks led to improved CO₂/N₂ selectivity, suggesting a strategy for the design of materials for post-combustion carbon capture.

Control over the surface functionality and microporosity in conjugated microporous polymers (CMPs) has been achieved by the post-synthetic modification of amines into amides of with different alkyl chains, one of which was chiral. The surface areas, pore volumes, carbon dioxide uptakes and isosteric heat of adsorption for carbon dioxide can be rationally tuned

The attractive intermolecular interactions between PIM-1 and polycyclic aromatic hydrocarbons were used to produce films with higher CO ₂ /N ₂ gas sorption selectivity and reduced ageing of permeability.