Nitrate electrocatalytic reduction (NO3RR) for ammonia production is a promising strategy to close the N‐cycle from nitration contamination, as well as an alternative to the Haber–Bosch process with ...less energy consumption and carbon dioxide release. However, current long‐term stability of NO3RR catalysts is usually tens of hours, far from the requirements for industrialization. Here, symmetry‐broken Cusingle‐atom catalysts are designed, and the catalytic activity is retained after operation for more than 2000 h, while an average ammonia production rate of 27.84 mg h−1 cm−2 at an industrial level current density of 366 mA cm−2 is achieved, obtaining a good balance between catalytic activity and long‐term stability. Coordination symmetry breaking is achieved by embedding one Cu atom in graphene nanosheets with two N and two O atoms in the cis‐configuration, effectively lowering the coordination symmetry, rendering the active site more polar, and accumulating more NO3− near the electrocatalyst surface. Additionally, the cis‐coordination splits the Cu 3d orbitals, which generates an orbital‐symmetry‐matched π‐complex of the key intermediate *ONH and reduces the energy barrier, compared with the σ‐complex generated with other catalysts. These results reveal the critical role of coordination symmetry in single‐atom catalysts, prompting the design of more coordination‐symmetry‐broken electrocatalysts toward possible industrialization.
A coordination‐symmetry‐breaking Cusingle‐atom catalyst enables a good balance between catalytic activity and long‐term stability in nitrate electroreduction to ammonia. The catalytic activity is retained after operation for more than 2000 h, while an average ammonia production rate of 27.84 mg h−1 cm−2 at an industrial level current density of 366 mA cm−2 is achieved.
Herein, it is reported the influence of solution processing and treatments, such as adding marginal solvent, ultrasonication, and UV treatment, on the resulting perovskite (CsPbBr3) quantum dot ...(QD)/poly(3‐hexylthiophene) (P3HT) composite nanofibril films (CNFs) to improve the charge dissociation and photonic synaptic performance. A photonic synaptic transistor with CNFs can perform fundamental functions, including short‐term plasticity, long‐term plasticity, spike‐number‐dependent, and spike‐time‐dependent plasticity, to mimic sensing, computing, and memory functions. Notably, a synaptic device with CNFs presents an ultralow energy consumption of 0.18 fJ and zero‐gate operation. The superior performance of synaptic devices with CNFs can be attributed to two factors: (i) homogeneous axial distribution of the QDs and (ii) the formation of P3HT nanofibrils and co‐aggregates. Therefore, enhanced interfacial charge transfer between QDs and P3HT, ensuring decent carrier transport capability, is achieved. Collectively, the composite artificial synapse successfully provides an effective guide that offers a new perspective for the fabrication of one‐dimensional self‐assembled nanostructure‐based artificial synapses emulating human‐like memory, neuromorphic computing, and artificial intelligent systems.
Semiconducting self‐assembled composite nanostructures via solution processing is a promising strategy to improve the charge dissociation and photonic synaptic performance. In this study, quantum dot/poly(3‐hexylthiophene) nanofibrils are studied to understand the morphology/optoelectronic relation. The composite artificial synapse exhibits fundamental functions, including short‐term plasticity, long‐term plasticity, and spike‐number‐dependent and spike‐time‐dependent plasticity with ultralow energy consumption of 0.18 fJ and zero‐gate operation.
A novel approach for using conjugated rod–coil materials as a floating gate in the fabrication of nonvolatile photonic transistor memory devices, consisting of n‐type Sol‐PDI and p‐type C10‐DNTT, is ...presented. Sol‐PDI and C10‐DNTT are used as dual functions of charge‐trapping (conjugated rod) and tunneling (insulating coil), while n‐type BPE‐PDI and p‐type DNTT are employed as the corresponding transporting layers. By using the same conjugated rod in the memory layer and transporting channel with a self‐assembled structure, both n‐type and p‐type memory devices exhibit a fast response, a high current contrast between “Photo‐On” and “Electrical‐Off” bistable states over 105, and an extremely low programing driving force of 0.1 V. The fabricated photon‐driven memory devices exhibit a quick response to different wavelengths of light and a broadband light response that highlight their promising potential for light‐recorder and synaptic device applications.
High‐performance photonic transistor memory devices are fabricated using conjugated rod–coil materials as a photoactive floating gate, in which the conjugated rods and side‐chain coils act as charge‐trapping and tunneling moieties, respectively. By inheriting their self‐assembled structure, both n‐type and p‐type memory devices exhibit a fast response, a current contrast over 105, and an extremely low programing driving force of 0.1 V.
Herein, interfacial engineering is demonstrated to improve the thermal stability of non‐fullerene bulk‐heterojunction (BHJ) OPVs to a practical level. An amphiphilic dendritic block copolymer (DBC) ...is developed through a facile coupling method and employed as the surface modifier of ZnO electron‐transporting layer in inverted OPVs. Besides showing distinct self‐assembly behavior, the synthesized DBC possesses high compatibility with plasmonic gold nanoparticles (NPs) due to the constituent malonamide and ethylene oxide units. The hybrid DBC@AuNPs interlayer is shown to improve device's performance from 14.0% to 15.4% because it enables better energy‐level alignment and improves interfacial compatibility at the ZnO/BHJ interface. Moreover, the DBC@AuNPs interlayer not only improves the interfacial thermal stability at the ZnO/BHJ interface but also endows a more ideal BHJ morphology with an enhanced thermal robustness. The derived device reserves 77% of initial PCE after thermal aging at 65 °C for 3000 h and yields an extended T80 lifetime of >1100 h when stored at a constant thermal condition at 65 °C, outperforming the control device. Finally, the device is evaluated to possess a T80 lifetime of over 1.79 years at room temperature (298 K) when stored in an inert condition, showing great potential for commercialization.
An amphiphilic dendritic block copolymer is developed to serve as an efficient surface modifier of ZnO electron‐transporting layer in an organic photovoltaic device. When using an interlayer based on its hybridization with gold nanoparticles, the device can deliver improved performance and possess a lifetime of over 1.79 years when stored at room temperature in inert conditions.
We have developed a rapid and homogeneous method for the highly selective detection of Hg2+ and Ag+ using Tween 20-modified gold nanoparticles (AuNPs). Citrate ions were found to still be adsorbed on ...the Au surface when citrate-capped AuNPs were modified with Tween 20, which stabilizes the citrate-capped AuNPs against conditions of high ionic strength. When citrate ions had reduced Hg2+ and Ag+ to form Hg−Au alloys and Ag on the surface of the AuNPs, Tween 20 was removed from the NP surface. As a result, the AuNPs were unstable under a high-ionic-strength solution, resulting in NP aggregation. The formation of Hg−Au alloys or Ag on the surface of the AuNPs was demonstrated by means of inductively coupled plasma mass spectroscopy and energy-dispersive X-ray spectroscopy. Tween 20-AuNPs could selectively detect Hg2+ and Ag+ at concentrations as low as 0.1 and 0.1 μM in the presence of NaCl and EDTA, respectively. Moreover, the probe enables the analysis of AgNPs with a minimum detectable concentration that corresponds to 1 pM. This probe was successfully applied to detect Hg2+ in drinking water and seawater, Ag+ in drinking water, and AgNPs in drinking water.
Donor–acceptor type polymers and supramolecules are promising electrets in photonic field‐effect transistor (FET)‐type memory because of their diversified polymer‐structure design and favorable ...mechanical tolerance. Using intermolecular association, supramolecule electrets can surpass donor–acceptor type polymers with versatile facile combining processes. Currently, there has been no application of charge‐transfer (CT) supramolecules in electrets of photonic FET memory devices. Herein, a novel series of CT‐based supramolecular electrets comprising poly(1‐pyrenemethyl methacrylate) (PPyMA) and 7,7,8,8‐tetracyanoquinodimethane (TCNQ) is used to elucidate the effect of CT on photonic FET memory. Accordingly, memory devices based on the supramolecular electret with an equimolar content of pyrene and TCNQ exhibit superior bistable memory switchability using electrical/photoprograming with UV (365 nm) and green light (525 nm). This shows a broad memory window of 34 V and favorable memory ratio of over 106 after 104 s. The memory performance can be attributed to the favorable molecular association and dispersion between pyrene and TCNQ in the solid state. The results provide evidence that CT‐based supramolecular electrets warrant applications in optoelectronic applications.
A series of charge transfer‐based supramolecular electrets comprising poly(1‐pyrenemethyl methacrylate) and 7,7,8,8‐tetracyanoquinodimethane are applied to elucidate the effect of charge transfer on photonic field‐effect transistor memory. Accordingly, the devices based on the supramolecular electret exhibit superior memory switchability using electrical/photoprograming under UV (365 nm) and green light, showing a broad memory window of 34 V and memory ratio of over 106 after 104 s.
Polymers with an abundant amorphous domain should facilitate energy dissipation upon stretching, making near amorphous π-conjugated polymers have immense potential in realizing intrinsically ...stretchable field-effect transistor (FET) devices. In this study, high mobility preservation under the stretched state is attempted by replacing typical alkyl-monothienyl (T-R) on a benzo1,2-b:4,5-b’dithiophene-difluorobenzothiadiazole backbone with three other biaxially extended side-chains, including alkyl-dithienyl (2T-R), branching alkyl-trithienyl (3T-R), and alkyl-benzotrithienyl (B3T-R) groups. Despite showing near amorphous features, the semi-2D BDT-based polymers with bulkier biaxially extended side chains (PBDT-2T, PBDT-3T, and PBDT-B3T) still present comparable mobility to the reference semicrystalline polymer (PBDT-T). Although these four polymers yield comparable mobility, they show distinctly different mobility retention in the stretched state. From the study of their mobility-stretchability relationship, the interdigitating and/or entanglement of these biaxially extended conjugated side chains are shown to play a nontrivial role in the resultant mechanical robustness against the stretching force. Owing to the proper spatial mobility and geometry, the branched 3T-R side chain possesses a more intense interdigitating and/or entanglement capability than the linear 2T-R one and the fused B3T-R one, providing better mechanical strength under stretched states. Meanwhile, it maintains sufficient interchain connectivity for intermittent interchain hopping to compensate for the 1D charge transport along the backbone, ensuring good charge transport even in the stretched state. As a result, the printed PBDT-3T film is demonstrated to deliver a high mobility retention of 73% at a 60% strain exerted parallel to the charge-transporting direction and a very stable mobility retention of 88% after 1000 stretching-releasing cycles at a 60% strain, being one of the best stretchable near amorphous conjugated polymers reported thus far. Our result underlines the effectiveness of using biaxially extended conjugated side chains to realize high-performance stretchable polymers.
Recent research interest in organic field‐effect transistor (FET) memory has shifted to the functionality of photoprogramming in terms of its potential uses in multibit data storage and ...light‐assisted encryption and its low‐energy consumption and broad response to various optical bands. Phototransistor memory can be modulated through both electrical stress and light illumination, allowing it to function as an orthogonal operation method without mutual interference. Herein, the basic design concepts, requirements, and architectures of phototransistor memory are introduced. Design architectures such as channel‐only, channel‐with‐photogate, photochromatic channel devices and floating gate, photoactive polymer, and organic molecule‐based electrets are systematically categorized. The operational mechanism and impact of effective combinations of channels and electrets are reviewed to provide a fundamental understanding of photoprogramming as well as its potential future developmental applications as nonvolatile memory. Furthermore, recent advances in phototransistors and their diverse applications, including nonvolatile memory, artificial synapses, and photodetectors, are summarized. Finally, the outlook for the future development of phototransistors is briefly discussed. A comprehensive picture of the recent progress in phototransistors is provided.
Herein, the basic design concepts and architectures of phototransistors are introduced. Design strategies involving channel‐only and channel‐with‐photogate devices as well as devices using floating gate, photoactive polymer, and organic molecule electrets are systematically categorized. Recent advances in phototransistors and their diverse applications: nonvolatile memory, artificial synapses, and photodetectors, are summarized. This review sheds light on the future development of phototransistors.
Up to now, researches on the mobility–stretchability of semiconducting polymers are extensively investigated, but little attention was paid to their morphology and field‐effect transistor ...characteristics under compressive strains, which is equally crucial in wearable electronic applications. In this work, a contact film transfer method is applied to evaluate the mobility–compressibility properties of conjugated polymers. A series of isoindigo–bithiophene conjugated polymers with symmetric carbosilane side chains (P(SiSi)), siloxane‐terminated alkyl side chains (P(SiOSiO)), and combined asymmetric side chains (P(SiOSi)) are investigated. Accordingly, a compressed elastomer slab is used to transfer and compress the polymer films by releasing prestrain, and the morphology and mobility evolutions of these polymers are tracked. It is found that P(SiOSi) outperforms the other symmetric polymers including P(Si─Si) and P(SiO─SiO), having the ability to dissipate strain with its shortened lamellar spacing and orthogonal chain alignment. Notably, the mechanical durability of P(SiOSi) is also enhanced after consecutive compress–release cycles. In addition, the contact film transfer technique is demonstrated to be applicable to investigate the compressibility of different semiconducting polymers. These results demonstrate a comprehensive approach to understand the mobility–compressibility properties of semiconducting polymers under tensile and compressive strains.
A contact film transfer method is applied to evaluate the mobility–compressibility properties of conjugated polymers. Accordingly, a compressed elastomer slab is used to transfer and compress the polymer films by releasing prestrain, and the morphology and mobility evolutions of the polymers are tracked. This technique is applicable to investigate the compressibility of varied semiconducting polymers.
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