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Carbon fiber electrode has the advantages of low cost, good chemical stability, and tunable performance, which can be utilized to develop high performance marine electric field sensors. Polyaniline/carbon fiber (PANI/CF) composite electrode doped with hydrochloric acid, sulfuric acid, and phosphoric acid are respectively fabricated by electrochemical in-situ polymerization, and their electrochemical performance and electric field response of the composite electrodes are studied respectively. The results show that conductive polyaniline film is uniformly formed on the surface of carbon fiber, and the characteristic redox peak occurs in the cyclic voltammetry test. Electrochemical impedance analysis shows that the low frequency (0.01 Hz) impedance of PANI/CF composite electrode decreases to at most 1/118 of that of the blank electrode, which is conducive to the quick response to weak underwater electric field signal. In the electric field response performance test, the potential drift of hydrochloric acid doped PANI/CF composite electrode is as low as 1.77 mV/d and it can better respond to 1 mV/10 mHz low-frequency and low-intensity electric field signal. It also has the minimum linearity error (0.111%), indicating the best response sensitivity among these modified electrodes. The preparation method of the composite electrode is simple and low-cost. Therefore, it is expected to be developed into a new generation of marine electric field sensor with low cost and high performance.

Surface amino modification of carbon fibre electrodes can significantly improve their electrochemical and electric field response properties. In this paper, we tune up the grafting voltage (3, 5, 7 V) and graft polyaminocyanine films on the surface of carbon fibres to modulate the structure and electrochemical properties of the electric double layer at the electrode/sea water interface. The results show that the higher the grafting potential, the more uniform the polyaminocyanine film on the carbon fibre surface and the more stable the electrode bilayer structure. The CF-7V has the best overall performance with a specific capacitance of 9.368 F·g-1, 31.6 times that of the blank group; the charge transfer resistance and low frequency capacitive resistance are significantly reduced; the 7-day potential drift is 1.68 mV, which can respond normally to low frequency weak electric field signals at 1 mHz and 0.03 mV/m, and the response sensitivity and accuracy of the electrodes have been significantly improved. The electric field response performance of the electrically grafted modified carbon fibre electrode is comparable to that of the Ag/AgCl electrode. This is a new type of high performance marine electric field sensor, which is expected to improve the detection capability of marine electric fields.

Rechargeable aluminium (Al) batteries (RABs) have long-been pursued due to the high sustainability and three-electron-transfer properties of Al metal. However, limited redox chemistry is available for rechargeable Al batteries, which restricts the exploration of cathode materials. Herein, we demonstrate an efficient Al-amine battery based on a quaternization reaction, in which nitrogen (radical) cations (R3 N.+ or R4 N+ ) are formed to store the anionic Al complex. The reactive aromatic amine molecules further oligomerize during cycling, inhibiting amine dissolution into the electrolyte. Consequently, the constructed Al-amine battery exhibits a high reversible capacity of 135 mAh g-1 along with a superior cycling life (4000 cycles), fast charge capability and a high energy efficiency of 94.2 %. Moreover, the Al-amine battery shows excellent stability against self-discharge, far beyond conventional Al-graphite batteries. Our findings pave an avenue to advance the chemistry of RABs and thus battery performance.

In the long-term electricity generation and driving sensor work process of marine sediment microbial fuel cells(MSMFCs), its cathode in the seawater may be embedded into the marine sediment, which will affect the electrochemical performance and lead to MSMFCs failure. The article simulated the embedding ratio of cathodes in sediment in the laboratory: 1/3, 1/2, 2/3, in order to investigate the changes of the electrochemical performance of the cathode and the electricity generation performance of MSMFCs. The results show that: the open circuit potential dropped and the required longer steady time with the higher embedding ratio of the cathode. Its capacitance decreased gradually, and the minimum capacitance was 32 F/cm2 (2/3 group), which was 0.72 times of the Blank. The kinetic activity decreased firstly and then increased, and its maximum activity was 1.61 times of the Blank (2/3 group); The maximum power density of the MSMFCs was 140.83 mW/m2 (1/3 group), which was 1.21 times of the Blank. With the increase of embedding ratio of the cathode in the marine sediment, its electrochemical performance and electricity generation performance of MSMFCs both fluctuates, but the normal operation of MSMFCs can still be ensured.

Helikale Nanographene (NG) mit hohen Quantenausbeuten und starken chiroptischen Antworten sind entscheidend für die Entwicklung von lumineszenten Materialien mit zirkularer Polarisation (engl. circular polarized luminescence, CPL). Hier berichten wir von der erfolgreichen Synthese neuartiger π‐erweiterter Doppel‐[7]Helicene (ED7Hs), bei denen sich zwei Helicen‐Einheiten meta bzw. para am zentralen Benzenring befinden. Sie sind damit strukturelle Isomere des bekannten ortho‐ED7H. Die strukturelle Integrität und Geometrie der ED7Hs wurde eindeutig durch Röntgen‐Einkristalldiffraktometrie aufgeklärt. Die ED7Hs besitzen eine ausgeprägte Fluoreszenz mit Quantenausbeuten über 40 %. Durch Variation der relativen Positionen der Doppel‐[7]Helicene am zentralen Benzenring (ortho, meta, para) kann eine außergewöhnliche Verstärkung der chiroptischen Eigenschaften registriert werden. Diese Verbesserung zeigt sich in einem etwa fünffachen Anstieg der Absorbanz und Lumineszenz‐Dissymmetriefaktoren (gabs und glum) sowie einer erhöhten CPL‐Helligkeit von bis zu 176 M−1 cm−1, was die Leistung der meisten helicenbasierten chiralen NGs übertrifft. Des weiteren zeigen DFT‐Simulationen, dass die relative geometrische Lage der [7]Helicene eine präzise Anpassung der elektrischen und magnetischen Übergangsdipolmomente zur Folge hat, welche die beobachteten Verstärkungen der chiroptischen Eigenschaften erklären. Diese Studie liefert eine effektive Strategie zur Verstärkung der CPL‐Eigenschaften chiraler Nanographene, welche ihre Anwendbarkeit als CPL‐Emitter verbessert. [ABSTRACT FROM AUTHOR]

Flexible wearable electronics have been developing rapidly in recent years, and one of its core devices, thin‐film transistor (TFT), is also attracting attention. Current TFT preparation processes usually require high annealing temperatures (>350 °C), which is not conducive to their application on most flexible substrates (PET, PEN, nanopaper, etc.). In this article, a strategy for the room temperature preparation of Nd:AIZO/Al2O3 dual‐layer TFT devices is proposed, which has appreciable electrical properties without additional annealing treatment. Taguchi orthogonal experimental methods are used to investigate the effects of three essential process parameters on the performance of the films and devices. As Nd:AIZO deposition time decreases and Al2O3 oxygen percentage and time during deposition increase, the μsat and SS of TFT devices are improved. With the preferred combination of parameters applied to the device preparation, the device exhibits a saturation mobility μsat of 24.3 cm2 V−1 s−1, a threshold voltage Vth of −1.4 V, a subthreshold swing SS of 0.21 V decade−1 and an Ion/Ioff ratio of 4.26 × 108. The ultra‐thin Al2O3 layer act as defect modification and form high‐speed electron transport in channel layer. The room temperature preparation of the dual‐layer TFT process proposed in this article is compatible with large‐size low‐cost flexible substrates. It has great potential for application in green flexible wearable electronics. [ABSTRACT FROM AUTHOR]

Covalent organic frameworks (COFs) have attracted considerable attention as adsorbents for capturing and separating gold from electronic wastes. To enhance the binding capture efficiency, constructing hydrogen‐bond nanotraps along the pore walls was one of the most widely adopted approaches. However, the development of absorbing skeletons was ignored due to the weak binding ability of the gold salts (Au). Herein, we demonstrated skeleton engineering to construct highly efficiently absorbs for Au capture. The strong electronic donating feature of diarylamine units enhanced the electronic density of binding sites (imine‐linkage) and thus resulted in high capacities over 1750 mg g−1 for all three COFs. Moreover, the absorbing performance was further improved via the ionization of diarylamine units. The ionic COF achieved 90 % of the maximal adsorption capacity, 1.63 times of that from the charge‐neutral COF within ten minutes, and showed remarkable uptakes of 1834 mg g−1, exceptional selectivity (97.45 %) and cycling stability. The theoretical calculation revealed the binding sites altering from imine bonds to ionic amine sites after ionization of the frameworks, which enabled to bind the AuCl4− via coulomb force and contributed to enhanced absorbing kinetics. This work inspires us to design molecular/ionic capture based on COFs. [ABSTRACT FROM AUTHOR]