The iodine adsorption capacity of porous organic polymers is greatly enhanced due to the extended π-conjugated units on the backbone.

A set of conjugated polymers based on poly(triphenylamine-phenothiazine) with carboxylic acid side groups have been synthesized and utilized as sensitizers for dye-sensitized solar cells (DSSCs). The polymers feature a conjugated side-chain consisting of a thiophene unit (PPAT4), alternating with either 3,4-ethylenedioxythiophene (EDOT, PPAT5) or EDOT–thiophene (PPAT6) as the π-bridge. This methodology constitutes a consolidated step to adjust the molecular HOMO and LUMO energy levels of dyes, hence red-shifting and broadening the absorption spectra of a conjugated polymer. Compared with the model compound (PAT), the polymers exhibit a higher molar extinction coefficient throughout the visible region, and a better photovoltaic performance in DSSCs with I⁻/I₃ ⁻ electrolyte. Interestingly, depending on the Suzuki coupling reaction, we obtain a fairly high degree of polymerization (DP values are 58, 46, and 38 for PPAT4, PPAT5 and PPAT6, respectively) based on the three polymers. More encouraging is that when using the high DP polymers as sensitizers, photoelectrochemical tests based on the DSSC format demonstrate a power conversion efficiency of 4.7%, 3.7% and 4.1% for PPAT4, PPAT5 and PPAT6, respectively, under the illumination of AM1.5G and 100 mW cm⁻². This presented a considerably high photo-to-electric conversion efficiency in polymer dye-sensitized solar cells, outperforming all polymer dye-sensitized solar cells previously reported.

A series of novel azo-functionalized copolymerized networks (simply known as NOP-34 series) with tunable permanent microporosity and highly selective carbon dioxide capture are disclosed. The synthesis was accomplished by Zn-induced reductive cross-coupling copolymerization of two nitrobenzene-like building blocks with different ‘internal molecular free volumes’ (IMFVs), i.e., 2,7,14-trinitrotriptycene and 2,2′,7,7′-tetranitro-9,9′-spirobifluorene, with different molar ratios. Increasing the content of spirobifluorene (SBF) segments with a smaller IMFV relative to that of triptycene leads to an unconventional rise–fall pattern in porosity. Unlike most reported porous copolymers whose surface area lies between the corresponding homopolymers, the copolymer NOP-34@7030 with 30% SBF segments unprecedentedly shows the largest Brunauer–Emmett–Teller specific surface area (up to 823 m² g⁻¹) as well as promoted CO₂ uptake abilities (from 2.31 to 3.22 mmol g⁻¹, at 273 K/1.0 bar). The 100% triptycene(TPC)-derived homopolymer (NOP-34@1000) with a moderate surface area shows the highest CO₂/N₂ IAST selectivity of 109 (273 K) among the five samples, surpassing most known nanoporous organic polymers. This may contribute significantly to our understanding of the relationship of IMFVs with the properties of copolymerized materials.