Herein, the photocatalytic activity of four conjugated porous polymers (CPPs) based on BOPHY moiety (named IEP-x , x = 7, 8, 9, and 10) and TiO2 hybrids thereof to produce hydrogen from water under UV–vis irradiation is described. All the polymers show better performance than TiO2, and the hybrid materials (only 10 wt % of polymer loading) show a higher hydrogen evolution rate than the sum of their components. The best value is recorded for the IEP-7@T-10 sample which shows 12-fold higher HER than the sum of its individual bare materials. Also, this sample with 1 wt % photodeposited platinum as cocatalyst shows a photonic efficiency ( , %) of 14.54, 4.4-fold higher than the photonic efficiency of Pt/TiO2, in the same conditions. The combination of time-resolved fluorescence with transient absorption spectroscopy (TAS) measurements with the use of electron and hole scavengers allows us to determine an effective charge transfer mechanism Type II as mainly responsible for the improved photocatalytic activity.

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Truxene-based porous polymers synthesized through the simple "solvent knitting" strategy from hexamethyl or tribenzyl truxene-based monomers (TxPP1 and TxPP2), and their corresponding TxPP@TiO2 hybrids are used as photocatalysts for H2 production from water using methanol as sacrificial agent, under UV-Vis light. These polymers present higher hydrogen evolution rate (HER) than TiO2, and remarkable thermo-and photo-stabilities. Hybrids TxPP-TiO2 exhibited intensely enhanced photocatalytic activity compared to TiO2 or TxPPs alone. In the presence of platinum (1%) as cocatalyst, HER from TxPP1@T-10 significantly boosted reaching values above 21000 µmol.g -1 .h -1 which to the best of our knowledge, represents the highest HER reported for hybrids based on TiO2 and conjugated porous polymers. Interestingly, small structural differences of the corresponding truxene monomers result in different photocatalytic behavior. We focused here on gaining insight on the charge transfer mechanism and rationalizing the different photocatalytic performances in order to establish clear structure-activity relationships. In fact, photoluminescence and transient absorption spectroscopy demonstrated that the remarkably enhanced photocatalytic activity of the most active hybrids (TxPP1@TiO2) can be attributed to the efficiently photogenerated electron-hole separation by a direct Z-scheme mechanism, while lower 2 performance of TxPP2@TiO2, is probably due to a less efficient heterojunction type II charge transfer mechanism.

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Developing highly efficient photocatalysts for artificial photosynthesis is one of the grand challenges in solar energy conversion. Among advanced photoactive materials, conjugated porous polymers (CPPs) possess a powerful combination of high surface areas, intrinsic porosity, cross‐linked nature, and fully π‐conjugated electronic systems. Here, based on these fascinating properties, organic–inorganic hybrid heterostructures composed of CPPs and TiO2 for the photocatalytic CO2 reduction and H2 evolution from water are developed. The study is focused on CPPs based on the boron dipyrromethene (BODIPY) and boron pyrrol hydrazine (BOPHY) families of compounds. It is shown that hybrid photocatalysts are active for the conversion of CO2 mainly into CH4 and CO, with CH4 production 4 times over the benchmark TiO2. Hydrogen evolution from water surpassed by 37.9‐times that of TiO2, reaching 200 mmol gcat−1 and photonic efficiency of 20.4% in the presence of Pt co‐catalyst (1 wt% Pt). Advanced photophysical studies, based on time‐resolved photoluminescence and transient absorption spectroscopy, reveal the creation of a type II heterojunction in the hybrids. The unique interfacial interaction between CPPs and TiO2 results in longer carriers’ lifetimes and a higher driving force for electron transfer, opening the door to a new generation of photocatalysts for artificial photosynthesis.