Conjugated microporous polymers (CMPs) have found extensive applications in various fields such as optoelectronics, CO2 capture, and catalysis. However, their potential in electrochemical supercapacitors as energy storage and H2 production systems remains relatively unexplored. This limited exploration can be attributed to certain challenges, including issues related to structural and electrochemical stability, as well as the relatively modest specific capacitance. Additionally, many of the CMPs discovered thus far have exhibited lower energy densities, further contributing to this underexplored aspect of their utility. In this study, we prepared two different CMPs [TPET-TTh and PyT-TTh CMPs] containing thienyltriazine units (TTh) for the redox mechanism and constructed electrodes for supercapacitor applications. The synthesized TPET-TTh and PyT-TTh CMPs displayed exceptionally high specific surface areas of 545 and 528 m² g⁻¹, respectively. Furthermore, their pore sizes were very similar, centered at approximately 0.39 and 0.36 nm, respectively. To evaluate their electrochemical properties, the TTh-CMPs were examined using cyclic voltammetry (CV) and galvanostatic charge/discharge (GCD). The resulting CV curves exhibited rectangular shapes, indicative of the characteristic behavior of electric double-layer capacitors, across a range of potential and scan rates. These TPET-TTh and PyT-TTh CMPs delivered nominal specific capacitances of 74 and 76 F g−1 at 0.5 A g−1, respectively. In addition, they exhibited outstanding capacity retentions of 95.2 and 97.30 % even after 2000 cycles [analyzed at 10 A g−1]. The TTh-CMPs also exhibited excellent light-capture capabilities. The PyT-TTh CMP has faster charge separation and lower charge recombination rates than TPET-TTh CMP. This results in a higher hydrogen evolution rate from the water decomposition reaction. The H2 production rate of PyT-TTh CMP could be as high as 18,533 μmol g−1 h−1, which is approximately 4-fold that of TPET-TTh CMP. This study offers a strategy for the design of TTh-containing CMPs that exhibit exceptional energy storage application and photocatalytic efficiency for H2 evolution.

Designing an organic polymer photocatalyst for efficient hydrogen evolution with visible and near-infrared (NIR) light activity is still a major challenge. Unlike the common behavior of gradually increasing the charge recombination while shrinking the bandgap, we present here a series of polymer nanoparticles (Pdots) based on ITIC and BTIC units with different π-linkers between the acceptor-donor-acceptor (A-D-A) repeated moieties of the polymer. These polymers act as an efficient single polymer photocatalyst for H2 evolution under both visible and NIR light, without combining or hybridizing with other materials. Importantly, the difluorothiophene (ThF) π-linker facilitates the charge transfer between acceptors of different repeated moieties (A-D-A-(π-Linker)-A-D-A), leading to the enhancement of charge separation between D and A. As a result, the PITIC-ThF Pdots exhibit superior hydrogen evolution rates of 279 µmol/h and 20.5 µmol/h with visible (>420 nm) and NIR (>780 nm) light irradiation, respectively. Furthermore, PITIC-ThF Pdots exhibit a promising apparent quantum yield (AQY) at 700 nm (4.76%).

High-entropy-alloy (HEA) nanocrystals hold immense potential for catalysis, offering virtually unlimited alloy combinations through the inclusion of at least five constituent elements in varying ratios. However, general and effective strategies for synthesizing libraries of HEA nanocrystals with controlled surface atomic structures remain scarce. In this study, a transferable strategy for developing a library of facet-controlled seed@HEA nanocrystals through seed-mediated growth is presented. The synthesis of seed@HEA core-shell nanocrystals incorporating up to ten different metallic elements, with control over the number of solid-solution HEA atomic layers is demonstrated. Epitaxial HEA growth on nanocrystal seeds with low-index and high-index facets leads to the formation of seed@HEA catalyst library with composition- and facet-dependent catalytic activities in both electrocatalysis and photocatalysis. In situ synchrotron X-ray absorption spectroscopy and density-functional theory calculations are employed to identify surface active sites of the HEA, rationalizing the high level of catalytic activities achieved. This work enables facet engineering in the multi-elemental chemical space and unveils the critical needs for their future development toward catalysis.

Covalent organic frameworks (COFs), which have layered stacking structures, extended pi-conjugation, and periodic frameworks have become a promising class of materials for a wide range of applications. However, their synthetic pathways frequently need high temperatures, enclosed systems under high pressures, an inert atmosphere, and extended reaction time, which restrict their practicality in real-world applications. Herein, the use of gamma irradiation is presented to synthesize highly crystalline COFs at room temperature under an open-air condition within a short time. This is demonstrated that there is no significant difference in crystallinity of COFs by gamma irradiation under air, N2 or Ar atmosphere conditions. Moreover, this approach can successfully fabricate COFs in the vessel with different degrees of transparency or even in a plastic container. Importantly, this strategy is applicable not only to imine linkage of COFs but also effective to the imide linkages of COFs. Most importantly, these COFs demonstrate improved crystallinity, surface area, and thermal stability in comparison to the corresponding materials synthesized via the solvothermal method. Finally, a COF synthesized through gamma irradiation exhibits remarkable photocatalytic activity in promoting the sacrificial hydrogen evolution from water, displaying a more catalytic efficiency compared with that of its solvothermal analogue. The advancement of new forms of energy sources has been the focus of research to develop more green and high-throughput synthetic techniques. In this work, gamma irradiation is used as a promising approach under an open-air condition at room temperature within a short time for the synthesis of high crystalline COFs. image

An organic synaptic transistor was fabricated with a covalent organic polymer MT-TP to mimic the behavior of biological synapses.

So far, achieving high apparent quantum yield (AQY) in polymeric photocatalysts at wavelengths up to 500 nm has never been achieved. Covalent organic polymers (COPs) have the advantage of high structure function tunability. However, despite decades of development, COPs still lag in achieving high AQY value, highlighting the need for an optimal COP structural design for efficient photocatalysis. Herein, we present a green synthetic approach to synthesize five hydrophilic and non-conjugated linkage with D-pi-A system benzoin-based COPs by self-condensation of multiformly monomers. Charge kinetic carrier and femtosecond transient absorption (fsTAS) demonstrate the efficient charge transport of benzoin-based COPs. Among the synthesized photocatalysts, B-PyTT-COP (D-pi-A) outperforms the COP family, with an excellent HER of 233.81 mu mol h-1 (77935 mu mol g- 1h- 1) using Platinum as co-catalyst. Remarkedly, B-PyTT-COP has achieved an exceptional ability to generate a high AQY value at 500 nm (65.35 %), surpassing all other materials examined thus far.

We investigated the performance that is improved in various applications through molecular structural alterations. Specifically, we emphasized the importance of controlling the branching densities of organic moieties as a useful tactic for varying the surface area and porosity of hybrid porous organic/inorganic polymers (HPPs), which include octavinylsilsesquioxane (OVS) units. This study shows that adjusting the branching densities could greatly enhance energy storage and hydrogen production. The two-branched chemical structure (4,7-dibromo-2,1,3-benzothiadiazole, BT-Br-2) and the four-branched organic compound (1,1,2,2-tetrakis(4-bromophenyl)ethylene, TPE-Br-4) are individually reacted with OVS and 1,3,6,8-tetrabromopyrene (Py-Br-4) twice to prepare the HPPs. These materials with high or low cross-linking density, as well as small and large surface areas, are synthesized by this dual reaction, which also produces HPPs with different cross-linking densities. Based on Brunauer-Emmett-Teller calculations, the OVS-Py-BT HPP has more than 4.5 times larger surface area than the OVS-Py-TPE HPP material. Remarkably, OVS-Py-BT HPP exhibited exceptional results for supercapacitor applications, with specific capacitance values of 248 and 54 F/g for OVS-Py-BT and OVS-Py-TPE HPPs, respectively, as determined by galvanostatic charge-discharge. OVS-Py-BT HPP significantly outperformed OVS-Py-TPE HPP in photocatalytic hydrogen evolution. This is evident from their respective hydrogen evolution rates: 1348 mu mol g(-1) h(-1) for OVS-Py-BT HPP and a much lower 11.3 mu mol g(-1) h(-1) for OVS-Py-TPE HPP.

Organic‐conjugated polymer dots (Pdots) are emerging as promising photocatalysts for solar‐driven hydrogen production. However, organic solvents are commonly used as cosolvents in photocatalytic systems to promote the dispersion of organic materials and improve the overall efficiency of the photocatalytic process. Herein, two naphthalenediimide (NDI)‐based Pdots, with and without surfactant, are fabricated and presented as highly efficient and stable photocatalysts for visible‐light‐driven hydrogen generation in a solvent‐free organic system for the first time. The prepared Pdots exhibit high photocatalytic activity and remarkable photostability. Achieving high efficiency and long‐term photostability is essential for the future commercialization of large‐scale hydrogen production. Furthermore, the NDI‐BTF‐PS‐PEG‐COOH Pdots of the dual acceptor (A1‐D‐A2‐D system) consisting of a strong acceptor (NDI, A1) and a weak acceptor (BTF, A2) exhibit high photocatalytic efficiencies and stabilities with Pt‐cocatalyst over 72 h. Thus, constructing A1‐D‐A2‐D NDI‐based Pdots is a promising approach to developing efficient and stable photocatalysts for solar‐driven hydrogen production.

Our study underscores that ICTDB, a polymer with one malononitrile substitution, outperforms in the HER and displays enhanced ultrafast charge transfer capabilities.

Organic conjugated polymer dots (Pdots) are considered promising photocatalysts for solar-driven hydrogen production. However, the impact of molecular weight on their photocatalytic activity remains unexplored. In this study, four thiophene-quinoxaline (PTQ)-based Pdots (D-A system) with tunable molecular weights were fabricated to elucidate the effects of molecular weight on Pdot photocatalytic activity. These Pdots serve as highly efficient and stable photocatalysts for visible-light-driven hydrogen generation in a solvent-free organic system, which was achieved for the first time. Low-molecular-weight Pdots exhibited minimal aggregation, small particle sizes, uniform morphology, enhanced charge transfer capability, and superior photocatalytic activity with remarkable photostability. Notably, L-PTQ10 and L-PTQ11 demonstrated exceptional hydrogen evolution rates of 15,807 and 10,411 mu mol g-(1) h-(1), respectively, when coupled with a Pt cocatalyst. The findings from our DFT and molecular dynamics (MD) calculations strongly support our hypothesis, highlighting the use of low-molecular-weight PTQ-based Pdots as a promising strategy to develop efficient and stable photocatalysts for solar-driven hydrogen production. This study presents the synthesis of thiophene-quinoxaline (PTQ)-based polymer dots (Pdots) with tunable molecular weights (D-A system) for the first time. Remarkably, Low-molecular weight Pdots exhibit minimal aggregation, small size, and enhanced charge transfer, leading to superior photocatalytic activity and remarkable photostability.

This study demonstrated the synthesis of imide–imine based COFs, boosting the electrical conductivity in the network due to the presence of dual electron-acceptor centers. This makes them efficient for light-induced hydrogen evolution reactions.

Conjugated microporous polymers (CMPs) have gained increased significance as crucial components in the field of photocatalytic H2 production due to their excellent ultraviolet-visible (UV-vis), and robust fluorescence. Herein, we used two types of reaction approaches including Suzuki and Sonogashira-Hagihara coupling to prepare six different types of CMPs for the first time to investigate and understand the reactivity of triphenylamine (TPA) and alkyne group linked CMPs for photocatalytic H2 evolution from H2O. Six different TPA-based CMPs including TPA-TPA (D-D), TPE-TPA (A-D), Py-TPA (A-D), TPA-TB-TPA (D-pi-D), TPE-TB-TPA (D-pi-A), and Py-TB-TPA (D-pi-A) CMPs have been designed and synthesized via Suzuki and Sonogashira-Hagihara coupling reaction, respectively. Our investigation of TPA-CMP materials showed that TPA-TPA, Py-TPA, and TPA-TB-TPA CMPs exhibited elevated Td10 values, measuring 557 degrees C, 508 degrees C, and 482 degrees C, respectively. Additionally, based on the results of thermal gravimetric analysis (TGA) and nitrogen adsorption-desorption measurements, these CMPs displayed specific surface areas (SBET) of 98, 913, and 459 m2 g-1, respectively. Furthermore, in the order presented, the Py-TPA, and Py-TB-TPA CMPs showcase hydrogen evolution rate (HER) values of 3633, and 16 700 mu mol g-1 h-1, respectively. As per density functional theory (DFT) calculations, the presence of an alkyne bridge in the Py-TB-TPA CMP can effectively hinder electron-hole recombination, prolong the lifetime of charge carriers, and improve the efficiency of their transfer and separation when compared to a similar CMP (Py-TPA CMP) lacking an alkynyl group. As a result, including an alkynyl (pi) bridge in the polymers led to an augmentation in their photocatalytic activity. This work presents various viewpoints regarding the development and architecture of high-performance CMPs incorporating alkynyl groups, showcasing their potential applications in photocatalysis. Through the successful application of Suzuki and Sonogashira coupling reactions, we have synthesized Py-TPA and Py-TB-TPA CMPs, demonstrating impressive hydrogen evolution rates (HER) of 3633 and 16 700 mu mol g-1 h-1, respectively.

Conjugated microporous polymers (CMPs) have been investigated as promising materials for enhancing energy storage in supercapacitors. Supercapacitors can be categorized into electric double-layer capacitors (EDLC) and pseudocapacitors, each differing in how their electrodes interact with ions. In the process of synthesizing CMPs, four specific building blocks, namely, triptycene (Try), pyrene (Py), tetraphenylethene (TPE), and benzo[c][1,2,5]thiadiazole (BT), were utilized. To synthesize Try-PyT CMP, Try-PyT-BT CMP, Try-TPET CMP, and Try-TPET-BT CMP, an efficient and environmentally friendly synthesis method was employed. This technique involved a one-pot Sonogashira coupling reaction. The analysis phase encompassed a range of assessments, including Fourier transform infrared (FTIR) spectroscopy, thermogravimetric analysis (TGA), C-13 solid-state NMR, scanning electron microscopy (SEM), transmission electron microscopy (TEM), N-2 adsorption/desorption isotherm measurements, cyclic voltammetry (CV), and galvanostatic charge-discharge (GCD). These analyses were performed to evaluate the chemical structures, thermal stability, porosity, morphology, and electrochemical properties of the four CMPs based on Try. The study highlighted the exceptional performance of these Try-based CMPs as electrode materials for supercapacitors. In particular, the Try-TPET-BT CMP demonstrated an impressive capacitance of 157 F g(-1) at 0.5 A g(-1), coupled with remarkable stability across 2000 cycles. Their substantial surface area and pore volume make them strong contenders for practical applications in real-world devices.

In recent years, both-organic frameworks (MOFs) based and covalent-organic frameworks (COFs) based materials have been extensively utilized for catalysis because of their specific surface area, tunable porosity, and structural versatility. Amongst the various MOFs/COFs-based catalysis implementation, catalytic hydrogen production (H-2) processes have subbed attention to alternative energy stemming from fossil fuel and the increasing global warming issue. As the growing demand for a sustainable, renewable, safe, and stable energy supply for the future is in urgent need, had urgently needed potential green energy or future energy attributed to the promising power-to-gas energy storage technology and the environmentally friendly zero carbon emission. Nowadays, most of the hydrogen is granted by the reforming reactions because of its mature large-scale production technology and economic benefits; in addition, electrochemical water splitting is another prospective route for hydrogen generation to fulfill the carbon reality. In this review, we provide an overview of the recent applications and developments of hydrogen production by using MOFs/COFs and the derived catalysts, including (1) the steam reforming reaction, (2) the dry reforming reaction, (3) the electrocatalytic water splitting, (4) the photocatalytic water splitting, and (5) the photo-electrocatalytic water splitting. Furthermore, we focus on the design of MOF/COF-based catalysts. Finally, the opportunities and challenges are also overviewed to guide the MOFs/COFs-derived catalysts applied for their hydrogen production (H-2). (C) 2023 Elsevier B.V. All rights reserved.

Designing heterostructure photocatalysts is a promising approach for developing highly efficient photocatalysts for hydrogen energy production. In this work, we synthesized a series of a covalent organic framework (COF)/g-C3N4 (CN) heterojunction photocatalysts, denoted as x % COF/CN (in which x indicates the weight % of COF andx = 5, 10, 20, 30, 40, 50, 90, 95, 100), for hydrogen production. The COF, which is a key component of the photocatalyst, was prepared by assembling benzothiadiazole (BT) and pyrene (Py) derivatives as building blocks. Integrating COF rods into the two-dimensional (2D) layered g-C3N4 structure significantly improved photo -catalytic H2 production. The hybrid system (30 % COF/CN) displayed an outstanding hydrogen evolution rate (HER) of 27540 +/- 805 mu mol g- 1h- 1, outperforming most known COFs and g-C3N4-based photocatalysts, besides exhibiting stable photocatalytic performance. Moreover, the apparent quantum yield (AQY) was 15.5 +/- 0.8 % at 420 nm. Experimental techniques and density functional theory (DFT) calculations demonstrated that the 30 % COF/CN heterostructure has broad visible-light absorption, adequate band energy levels, and the best chemical reactivity descriptors compared to the individual components, resulting in effective carrier separation and excellent performance. Our findings offer a valuable strategy for developing highly efficient and stable hetero-junction photocatalysts for visible-light-driven H2 evolution.

Abstract High-entropy-alloy (HEA) nanocrystals consisting of a minimum of five elements have recently emerged as a versatile family of catalysts due to immense chemical space and tunability 1-3 . However, there are no effective strategies for synthesizing libraries of HEA nanocrystals with controlled surface atomic structures of exposed facets for boosting catalytic performance 4-19 . Due to the distinct nucleation and growth kinetics of constituent metals and their distinctive crystal structures, it is incredibly challenging to confine five or more different metal species situated on the nanocrystal surface with a specific arrangement but also in a high-entropy random mixing state. Here we present a straightforward strategy to craft a library of facet-controlled HEA nanocrystals with up to ten dissimilar metallic elements (Pt, Pd, Ir, Ru, Rh, Os, Au, Fe, Co, and Ni) by solution-phase layer-by-layer epitaxial growth, enabling the design of 638 distinct catalysts with 5 to 10 elements in equimolar ratios. The subnanometer-thick solid-solution HEA atomic layers can be deposited epitaxially on nanocrystal seeds with {100} and {111} facets, thus achieving HEA shells with square and hexagonal atomic arrangements, respectively. The hollow HEA nanocages with ultrathin walls along a specific direction can be further fabricated via post-synthetic chemical etching. Three facet-dependent catalytic actives of HEA nanocrystals are discovered in electrocatalysis and photocatalysis, and their catalytic facets with real active sites are also identified by in situ synchrotron X-ray absorption spectroscopy and density-functional theory calculations. Our work enables facet engineering in the multi-elemental space and unveils the critical needs for their future development toward catalysis.

Heterocyclic moieties, such as benzimidazole, are examples of important nuclei that have found widespread use in a variety of scientific subfields, such as medical and applied chemistry. In this study, we described the photocatalytic synthesis of numerous different benzimidazole derivatives using a solid-state acid composed of zirconium oxosulfate embedded into carbon (ZrOSO4@C). A metal-organic framework (MOF), known as UiO-66, was used as a precursor for the synthesis of ZrOSO4@C via carbonization in the presence of sulfuric acid. ZrOSO4@C was able to catalyze the reaction effectively, allowing for a condensation and cyclization to take place in a single vessel, which resulted in a high yield (77-98%) of benzimidazoles that were of high purity with the byproducts of water, and hydrogen (H2) gas. Our catalyst allowed for an improvement in the synthesis of many different benzimidazole derivatives by using a wide array of aromatic aldehydes including aryl and heterocycles that included electron-donating or -withdrawing groups. Using a broad variety of analytical approaches, further analysises were conducted to examine the reaction process

This study aims to synthesize three conjugated microporous polymers (CMPs) [Py-F CMP, TPE-F CMP, and TBN-F CMP] via the Suzuki coupling reaction of 9,9-dihexylfluorene-2,7-diboronic acid [F-B(OH)2] with three bromi-nated derivatives, pyrene (Py), tetraphenylethylene (TPE), and tetrabenzonaphthalene (TBN). The functional groups and chemical structures of the three synthesized CMPs were confirmed using FTIR and solid-state NMR analyses. Thermogravimetric analysis (TGA) revealed that TBN-F CMP has the most outstanding Td10 = 418 degrees C and char yield = 63.3 wt% compared to the other two samples. The BET surface area and average pore size of TBN-F CMP were measured to be 200 m2 g-1 and ca. 1.8 nm, respectively. Furthermore, with excellent pho-toluminescence (PL) properties, all three new CMPs were well characterized using a spectrophotometer, and the fluorescence emission spectra were clearly drawn. As a result, we found that Py-F CMP can detect Pb2+ ions specifically and selectively compared to the other two CMPs. The sensitivity of Pb2+ was calculated and fitted with linear coefficients (R2 = 0.9752) to determine the Pb2+ ion concentration over the ranges of 0.1-2.0 mu M, and the detection limit was estimated to be 0.01 mu M. Finally, with outstanding capacitance and stability of up to 195 F g-1 and 90% over 2000 cycles, TBN-F-based CMP has been successfully applied to electrochemical measurements.

The importance of conjugated microporous polymers (CMPs) as active components in photocatalytic hydrogen evolution is growing due to its intense ultraviolet-visible (UV-vis) absorption, potent fluorescence, and high carrier transport capacity, dibenzo[g,p]chrysene shows notable photophysical and electrical features. This is because CMPs have stiff molecular structures with large & pi;-conjugation. In this section, we describe our approach and syntheses of three types of polymers for the first time to determine the reactivity of dibenzo[g,p]chrysene (TBN)-based CMPs for photocatalytic H2 evolution and energy storage applications. Three TBN-based CMPs, TBN-TBN (D-D), TBN-TBN-TPA (A-D), and TBN-TBN-BT (D-A), were synthesized via Sonogashira-Hagihara coupling. TBN-CMP materials were used as working electrodes for energy storage applications. The TBN-TBN-BT CMP demonstrated excellent capacity retention (98.2%) over 2000 cycles and high capacitor (130 F g-1) at 0.5 A g- 1 are in the following order 8452, 9800, and 3060 & mu;mol g - 1h- 1for TBN-TBN, TBN-TBN-TPA, and TBN-TBN-BT CMPs, respectively. These findings suggest that using TBN as an acceptor increases the number of active sites for proton reduction, thereby boosting the rate of H2 evolution. , in accordance with electrochemical performance. Furthermore, the hydrogen evolution rate (HER) results

The higher the polarity or the hydrogen bond donor ability of the solvent, the more easily COFs crystallize, and the higher the COF crystallization, the higher the photocatalytic H 2 evolution.