Recently, great progress has been achieved in the design and preparation of conjugated organic polymer photocatalysts for hydrogen generation. However, it is still challenging to develop an organic ...polymer photocatalyst with high photoconversion efficiency. Rational structure design of organic polymer photocatalysts holds the key point to realize high photocatalytic performance. Herein, a series of donor–π–acceptor (D–π–A) conjugated organic copolymer photocatalysts is developed using statistical copolymerization by tuning the feed molar ratio of pyrene (donor) to dibenzothiophene‐S,S‐dioxide (acceptor) units. It reveals that the photocatalytic activity of the resulting copolymers is significantly dependent on the molar ratio of donor to acceptor, which efficiently changes the polymer structure and component. When the monomer feed ratio is 25:75, the random copolymer PyBS‐3 of 10 mg with Pt cocatalyst shows a high hydrogen evolution rate of 1.05 mmol h−1 under UV/Vis light irradiation using ascorbic acid as the hole‐scavenger, and an external quantum efficiency of 29.3% at 420 nm, which represents the state‐of‐the‐art of organic polymer photocatalysts. This work demonstrates that statistical copolymerization is an efficient strategy to optimize the polymer structure for improving the photocatalytic activity of conjugated organic polymer catalysts.
The photocatalytic activity of D–π–A copolymer photocatalysts can be boosted through statistical copolymerization by varying the ratio of electron donor to acceptor, and an attractive hydrogen evolution rate of 1.05 mmol h−1 is obtained by a copolymer (10 mg) with optimized polymer structure, which is also evidenced by a water‐draining experiment.
Conjugated microporous polymers (CMPs) with donor‐acceptor (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 dibenzob,dthiophene‐S,S‐dioxide (BTDO) containing CMP photocatalysts using tetraphenylethylene (TPE) or dibenzog,pchrysene (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, DBC has a planar molecular structure with extended π‐conjugation, which promotes the charges transmission and light‐induced electron/hole separation. As a result, the polymer DBC‐BTDO produced from DBC donor shows a remarkable photocatalytic hydrogen evolution rate (HER) of 104.86 mmol h‐1 g‐1 under full arc light (λ > 300 nm), which is much higher than that of the polymer TPE‐BTDO (1.80 mmol h‐1 g‐1), demonstrating that DBC can be an efficient electron donor for constructing D‐A polymer photocatalysts with high photocatalytic activity for hydrogen evolution.
A conjugated microporous polymer photocatalyst adopting dibenzog,pchrysene with planar structure and extended π‐conjugation as the electron donor shows a high hydrogen evolution rate of 104.86 mmol h−1 g−1 under full arc light (λ > 300 nm).
We report a low-cost water-in-salt electrolyte, of 30 m ZnCl2, which enables a dendrite-free Zn metal anode to possess a high coulombic efficiency (CE). In asymmetric Zn‖Zn cells with a limited mass ...of plated Zn as the working electrode, the ZnCl2 WiSE improves the average CE of the Zn anode to 95.4% from 73.2% in 5 m ZnCl2.
Poly(thiophene) as a kind of n‐doped conjugated polymer with reversible redox behavior can be employed as anode material for lithium‐ion batteries (LIBs). However, the low redox activity and poor ...rate performance for the poly(thiophene)‐based anodes limit its further development. Herein, a structure‐design strategy is reported for thiophene‐containing conjugated microporous polymers (CMPs) with extraordinary electrochemical performance as anode materials in LIBs. The comparative study on the electrochemical performance of the structure‐designed thiophene‐containing CMPs reveals that high redox‐active thiophene content, highly crosslinked porous structure, and improved surface area play significant roles for enhancing electrochemical performances of the resulting CMPs. The all‐thiophene‐based polymer of poly(3,3′‐bithiophene) with crosslinked structure and a high surface area of 696 m2 g−1 exhibits a discharge capacity of as high as 1215 mAh g−1 at 45 mA g−1, excellent rate capability, and outstanding cycling stability with a capacity retention of 663 mAh g−1 at 500 mA g−1 after 1000 cycles. The structure–performance relationships revealed in this work offer a fundamental understanding in the rational design of CMPs anode materials for high performance LIBs.
A structure‐design strategy is developed for thiophene‐containing conjugated microporous polymers with extraordinary electrochemical performances as anode materials for lithium‐ion batteries. The polymer of poly(3,3′‐bithiophene) exhibits a high reversible capacity of 1215 mAh g−1 at 45 mA g−1, and outstanding cycling stability with a capacity retention of 663 mAh g−1 at 500 mA g−1 after 1000 cycles.
Recent studies have demonstrated that dihydrophenazine (Pz) with high redox‐reversibility and high theoretical capacity is an attractive building block to construct p‐type polymer cathodes for ...dual‐ion batteries. However, most reported Pz‐based polymer cathodes to date still suffer from low redox activity, slow kinetics, and short cycling life. Herein, a donor–acceptor (D–A) Pz‐based conjugated microporous polymer (TzPz) cathode is constructed by integrating the electron‐donating Pz unit and the electron‐withdrawing 2,4,6‐triphenyl‐1,3,5‐triazine (Tz) unit into a polymer chain. The D–A type structure enhances the polymer conjugation degree and decreases the band gap of TzPz, facilitating electron transportation along the polymer skeletons. Therefore the TzPz cathode for dual‐ion battery shows a high reversible capacity of 192 mAh g−1 at 0.2 A g−1 with excellent rate performance (108 mAh g−1 at 30 A g−1), which is much higher than that of its counterpart polymer BzPz produced from 1,3,5‐triphenylbenzene (Bz) and Pz (148 and 44 mAh g−1 at 0.2 and 10 A g−1, respectively). More importantly, the TzPz cathode also shows a long and stable cyclability of more than 10 000 cycles. These results demonstrate that the D–A structural design is an efficient strategy for developing high‐performance polymer cathodes for dual‐ion batteries.
A dihydrophenazine‐based conjugated porous polymer cathode with donor–acceptor molecular structure shows a high reversible capacity of 192 mAh g−1 at 0.2 A g−1 with excellent rate performance and ultra‐stable cyclability more than 10 000 cycles.
The design and synthesis of conjugated semiconducting polymers for photocatalytic hydrogen evolution have engendered intense recent interest. However, most reported organic polymer photocatalysts ...show a relatively broad band gap with weak light absorption ability in the visible light region, which commonly leads to a low photocatalytic activity under visible light. Herein, we synthesize three novel dithieno3,2-
b
:2′,3′-
d
thiophene-
S
,
S
-dioxide (DTDO) containing conjugated polymer photocatalysts by a facile C-H arylation coupling polymerization reaction. The resulting polymers show a broad visible light absorption range up to 700 nm and a narrow band gap down to 1.81 eV due to the introduction of the DTDO unit. Benefiting from the donor-acceptor polymer structure and the high content of the DTDO unit, the three-dimensional polymer
PyDTDO-3
without the addition of a Pt co-catalyst shows an attractive photocatalytic hydrogen evolution rate of 16.32 mmol h
−1
g
−1
under visible light irradiation, which is much higher than that of most reported organic polymer photocatalysts under visible light.
Narrow band gap conjugated polymer photocatalysts containing dithieno3,2-
b
:2′,3′-
d
thiophene-
S
,
S
-dioxide show an attractive photocatalytic hydrogen evolution rate of 16.32 mmol h
−1
g
−1
under visible light irradiation.
Surface passivation technology provides noble‐metal materials with limited chemical stability, especially under highly acidic condition. To design effective strategy to enhance stability of ...noble‐metal particles, an understanding of their surface anticorrosion mechanism at the atomic level is desirable by using two‐dimensional (2D) noble‐metal coordination polymer (CP) as an ideal model for their interfacial region. With the protection of 2‐thiobenzimidazole (TBI), we isolated two Ag‐based 2D CPs, {Ag14(TBI)12X2}n (S−X, where S denotes sheet and X=Cl or Br). These compounds exhibited excellent chemical stability upon immersion in various common solvents, boiling water, boiling ethanol, 10 % hydrogen peroxide, concentrated acid (12 M HCl), and concentrated alkali (19 M NaOH). Systematic characterization and DFT analyses demonstrate that the superior stability of S−X was attributed to the hydrophobic organic shell and dynamic proton buffer layer acting as a double protective “shield”.
Acid resistance (12 M HCl) was made possible for two isomorphic two‐dimensional silver‐based coordination polymers. Protection is provided by a hydrophobic organic shell and a dynamic proton buffer layer via a thiolate‐thione tautomerism of 2‐thiobenzimidazole ligands. Thus, these ligands are promising surface inhibitors, acting as a dual protective shield against metal corrosion.
Photocatalytic hydrogen evolution is an attractive method for the acquisition of clean and sustainable energy with the use of solar power. Most reported studies have been carried out in scarce pure ...water. Therefore, the development of an artificial photosynthesis system that works perfectly with the earth's abundant seawater would be attractive. Herein, a supramolecular strategy for photocatalytic hydrogen production from the simulated seawater under sunlight irradiation (AM 1.5G, 100 mW cm−2) is presented using a water‐soluble, conjugated molecule as the photosensitizer and the photodeposited Pt nanoparticles as the catalyst. Inspired by the natural photosynthesis system, unprecedented advantage of the chloride ions in seawater is taken and the formation of supramolecular structure is promoted by electrostatic interactions between chloride ions and the fine‐designed PorFN, which further facilitates the loading of Pt nanoparticles and multielectron transfer. As a result, a hydrogen evolution rate of 10.8 mmol h−1 g−1 is achieved in the simulated seawater. Moreover, the photocatalytic activity shows relatively low dependence on the light intensity, which is of great importance for practical applications.
A water‐soluble conjugated molecule for solar‐driven hydrogen evolution from seawater is developed. The formation of the supramolecular structure induced by the electrostatic interactions between chloride ions and the rationally designed positively charged small molecule facilitates the loading of Pt nanoparticles and promotes light‐induced charge carrier transport and separation.
The preparation of carbon materials usually involves the decomposition of precursors and the reorganization of the as‐generated fragments. However, the cleavage of bonds and the simultaneous ...formation of new bonds at nearly the same positions prevents effective yet precise fabrication. Herein, a supramolecular precursor, cucurbit6uril, that contains multiple bonds with distinct bond strengths is proposed to decouple the twin problem of simultaneous bond cleavage and formation, allowing multistage transformations to hierarchical porous carbon and metal‐doped carbon in a single yet effective pyrolysis step without the need of a template or additional purification. As a proof‐of‐concept, the Fe‐doped carbon electrocatalysts realized a Pt/C‐like half‐wave potential of 0.869 V vs. RHE and small Tafel slope of 51.3 mV dec−1 in oxygen reduction reaction.
Making mesopores: The supramolecular interactions within cucurbit6uril enable a step by step pyrolysis mechanism, which aids the construction of mesopores and heteroatom doping in the resulting carbon material. The iron‐doped mesoporous carbon is highly efficient in the oxygen reduction reaction (ORR).
Fully unprotected peptide o‐aminoanilides can be efficiently activated by NaNO2 in aqueous solution to furnish peptide thioesters for use in native chemical ligation. This finding enables the ...convergent synthesis of proteins from readily synthesizable peptide o‐aminoanilides as a new type of crypto‐thioesters. The practicality of this approach is shown by the synthesis of histone H2B from five peptide segments. Purification or solubilization tags, which are sometimes needed to improve the efficiency of protein chemical synthesis, can be incorporated into the o‐aminoanilide moiety, as demonstrated in the preparation of the cyclic protein lactocyclicin Q.
Making it easier to make the link: The activation of fully unprotected peptide o‐aminoanilides with NaNO2 in an aqueous buffer enabled their use as peptide crypto‐thioesters in native chemical ligation (see scheme; MPAA=4‐mercaptophenylacetic acid). The practicability and unique advantages of this method were demonstrated by the total chemical synthesis of histone H2B and lactocyclicin Q.
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