The redox-activity of Cl−-hosting polypyrene cathode in dual-ion batteries can be tuned by tailoring the linking patterns.

It is challenging for polymer photocatalysts to achieve high photocatalytic performance under visible light due to their weak light absorption in visible light region. Herein, a universal strategy for boosting the photocatalytic activity of donor-acceptor (D-A) conjugated polymer photocatalysts upon visible light irradiation by inserting a π-spacer of thiophene unit between the electron donors and acceptors to form a D-π-A molecular structure is reported. The introduction of thiophene unit with narrow band gap can enhance the conjugation degree of the polymer chains and extend the light absorption range. Meanwhile, the introduction of thiophene spacer through ternary copolymerization also enables the controllability on the chemical structure of the resulting D-π-A polymers by altering the feed ratio between the electron donors and acceptors. The optimized D-π-A copolymer photocatalyst shows an impressive hydrogen evolution rate (HER) of 78.4 mmol h -1 g -1 under visible light irradiation, and the HER could be further improved to 127.9 mmol h -1 g -1 under UV-vis light irradiation by loading 1 wt% Pt co-catalyst. More importantly, this strategy can also be extended to other polymeric photocatalysts with different donor and acceptor units, demonstrating the universality for enhancing the photocatalytic activity of polymeric photocatalysts.

Photocatalytic hydrogen production based on dibenzothiophene-S,S-dioxide (BTDO)-containing polymer photocatalysts have attracted much attention in recent years, due to the high hydrophilicity and strong electron withdrawing capability of BTDO. However, most...

Organic polymers with conjugated architectures have been widely exploited as photocatalyst materials for hydrogen generation. However, it is still an enormous challenge to develop photocatalysts with high hydrogen generation activity under natural sunlight, which is pretty significant for practical applications. Herein, two conjugated microporous polymer photocatalysts with definite D−π–A structures are designed and prepared using dibenzo­[g,p]­chrysene or pyrene with planar conjugated architecture as electron donors, thiophene as a π-spacer, and dibenzo­[b,d]­thiophene-S,S-dioxide as an electron acceptor. Benefiting from the efficient separation of light-generated electrons/holes due to the definite D−π–A structure and the broad light absorption range, the bare polymer Py-TP-BTDO could deliver a high photocatalytic hydrogen evolution rate (HER) of 115.03 mmol h–1 g–1 upon exposure to visible light (λ > 420 nm). Impressively, the outdoor photocatalytic experiment reveals that abundant and continuous hydrogen bubbles could be produced fast and visually observed under natural sunlight by the Py-TP-BTDO polymer film with a large active area of 120 cm2. A water-drainage experiment further demonstrates that 1224 mL of hydrogen gas could be produced by 25 mg of a polymer photocatalyst with 3 wt % Pt cocatalyst under natural sunlight in 7 h, corresponding to a high HER of 312.24 mmol h–1 g–1, which represents the state of the art of organic photocatalyst materials to date. The high photocatalytic activity under natural sunlight suggests the potential of the developed Py-TP-BTDO polymer photocatalyst in the practical applications for photocatalytic hydrogen production.

electronic structure. [3][4][5] Nevertheless, most inorganic photocatalysts suffer from low activity under visible light, complexity in the preparation, and the limited natural resources. Recent studies demonstrated that organic semiconductors could be a promising class of photocatalysts for hydrogen evolution because of their diverse structures, various synthetic strategies, and tunable electronic properties. [6][7][8] To date, various organic polymers with conjugated skeletons have been developed as photocatalysts for hydrogen evolution. [9][10][11] In particular, significant advances in the preparation of conjugated microporous polymer (CMP) photocatalysts with high photocatalytic activity have been achieved. [12][13][14] Many studies revealed that designing a donor-acceptor (D-A) molecular structure is an efficient strategy to boost the photocatalytic activity of conjugated polymer photocatalysts, [15][16][17][18] since the intrinsic electron push-pull effect in a D-A conjugated polymer could promote the separation of light-induced hole/ electron. The nature of electron donor and acceptor units plays a key point in the charges transfer and separation, which affect significantly the photocatalytic activity. Therefore, the selection of electron donor and acceptor is of great importance for constructing organic polymer photocatalysts with high photocatalytic activity. In general, aromatic heterocyclic compounds with narrow band gap are commonly used as electron acceptors, and aromatic hydrocarbons with delocalized π-electron are employed as electron donors to build D-A type polymer photocatalysts. Based on the developed D-A polymer photo catalysts to date, [15,[19][20][21][22] dibenzo[b,d]thiophene-S,S-dioxide (BTDO) might be the most effective acceptor unit due to its strong electronwithdrawing capability and high hydrophilicity, [23][24][25] and pyrene with planar molecular structure and large delocalized π-electron system is the most effective electron donor to prepare high performance polymer photocatalysts. [26,27] Although there have been significant advances in the photo catalytic activity of polymer photocatalysts by structure optimization, [28,29] the limited scope of high efficient electron donors and acceptors hinders the further development of organic polymer photo catalysts. To further improve the photocatalytic activity and enrich the D-A) molecular structure show high photocatalytic activity for hydrogen evolution due to the efficient light-induced electron/hole separation, which is mostly determined by the nature of electron donor and acceptor units. Therefore, the selection of electron donor and acceptor holds the key point to construct high performance polymer photocatalysts. Herein, two dibenzo[b,d]thiophene-S,Sdioxide (BTDO) containing CMP photocatalysts using tetraphenylethylene (TPE) or dibenzo[g,p]chrysene (DBC) as the electron donor to investigate the influence of the geometry of electron donor on the photocatalytic activity are design and synthesized. Compared with the twisted TPE donor,...

Conjugated polymer photocatalysts have received extensive attention in the field of photocatalytic hydrogen evolution owing to their tunable molecular structures and electronic properties. Herein, we developed three donoracceptor (D-A) type thiophene-containing narrow-band-gap conjugated polymers with pyrene as a donor and different fused-thiophene derivatives as acceptors via direct C-H arylation coupling polymerization. It was found that the band gap of the polymers can be tuned by adjusting the number of the fused-thiophene rings. The visible light absorption range can be extended by increasing the number of the thiophene rings, the planar molecular structure for both donor and acceptor units facilitates the charge transmission along the polymer skeleton, and the D-A type polymer structure promotes the dissociation of photo-induced electrons and holes. As a result, a high photocatalytic hydrogen evolution rate of 33.07 mmol h −1 g −1 was obtained by PyTP-2 with an optimized molecular structure under visible light irradiation (λ > 420 nm) without the aid of Pt co-catalyst. In addition, PyTP-2 also shows a photocatalytic activity for oxygen evolution with an average oxygen evolution rate of 58.37 µmol h −1 g −1 .

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We report here 4,4-bis(2-ethylhexyl)-4H-silolo[3,2-b:4,5-b']dithiophene (SiDT) as an electron donor to construct a donor-acceptor type conjugated polymer (PSiDT-BTDO) photocatalyst with a narrow band gap by employing dibenzo[b,d]thiophene-S,S-dioxide as the electron acceptor....