Pushing the Electrochemical Performance Limits of Polypyrrole Toward Stable Microelectronic Devices

Conducting polymers have achieved remarkable attentions owing to their exclusive characteristics,for instance,electrical conductivity,high ionic conductivity,visual transparency,and mechanical tractability.Surface and nanostructure engineering of conjugated conducting polymers offers an exceptional pathway to facilitate their implementation in a variety of scientific claims,comprising energy storage and production devices,flexible and wearable optoelectronic devices.A two-step tactic to assemble high-performance polypyrrole(PPy)-based microsupercapacitor(MSC)is utilized by transforming the current collectors to suppress structural pulverization and increase the adhesion of PPy,and then electrochemical co-deposition of PPy-CNT nanostructures on rGO@Au current collectors is performed.The resulting fine patterned MSC conveyed a high areal capacitance of 65.9 mF cm^(−2)(at a current density of 0.1 mA cm^(−2)),an exceptional cycling performance of retaining 79%capacitance after 10,000 charge/discharge cycles at 5 mA cm^(−2).Benefiting from the intermediate graphene,current collector free PPy-CNT@rGO flexible MSC is produced by a facile transfer method on a flexible substrate,which delivered an areal capacitance of 70.25 mF cm^(−2) at 0.1 mA cm^(−2) and retained 46%of the initial capacitance at a current density of 1.0 mA cm^(−2).The flexible MSC is utilized as a skin compatible capacitive micro-strain sensor with excellent electromechanochemical characteristics.

Ceramic composites toughened by vat photopolymerization 3D printing technology

High strength and high toughness are mutually exclusive in structural materials.In ceramic materials,increasing toughness usually depends on the introduction of a ductile phase that reduces the strength and high-temperature stability of the material.In this work,vat photopolymerization 3D printing technology was used to achieve toughening of ceramic composite material.The friction sliding of the 3D-printed ceramic macrolayer structure results in effective energy dissipation and redistribution of strain in the whole structure,and macroscale toughening of the ceramic material is realized.In addition,the bridging and elongation of the crack in situ amorphous ceramic whiskers were significant microscopic toughening results,coupled with the toughening of the crack tip of nano-ZrO_(2).Multiscale collaborative toughening methods based on 3D-printed ceramics should find wide applications for materials in service at extreme high temperatures.

Platinum nickel alloy-MXene catalyst with inverse opal structure for enhanced hydrogen evolution in both acidic and alkaline solutions

The development of an efficient Pt-based electrocatalyst in acidic and alkaline electrolytes is of great significance to the field of electrocatalytic hydrogen evolution.Herein,we report a strategy for in situ growth of Pt_(3)Ni truncated octahedrons on Ti3C2Tx nanosheets and then obtain an ordered porous catalyst via a template method.Meanwhile,we use the finite element calculation to clarify the relationship between the component structure and performance and find that the performance of the spherical shell microstructure catalyst is higher than that of the disc structure catalyst,which is also verified by experiments.The experimental analysis shows that the ordered porous catalyst is conducive to enhancing electrocatalytic hydrogen evolution activity in acidic and alkaline electrolytes.In an acidic solution,the overpotential is 25 mV(10 mA·cm^(−2)),and the Tafel slope is 22.86 mV·dec−1.In an alkaline solution,the overpotential is 44.1 mV(10 mA·cm^(−2)),and the Tafel slope is 39.06 mV·dec−1.The synergistic coupling between Ti3C2Tx and Pt_(3)Ni nanoparticles improves the stability of the catalyst.The in situ growth strategy and design of microstructure with its correlation with catalytic performance represent critical steps toward the rational synthesis of catalysts with excellent catalytic activity.

A Novel Route to Synthesize N,N-Dimethyl Arylmethylamines from Aryl Aldehydes, Hexamethylenetetramine and Hydrogen

Developing simple and green routes to access valuable chemicals is of significance.Herein,we present a green and novel route to synthesize N,N-dimethyl arylmethylamines(DAMAs)from hexamethylenetetramine(HMTA)and aryl aldehydes in the presence of hydrogen,and a series of DAMAs can be obtained in good yields.This approach opens the precedent for HMTA as N,N-dimethylamine source to synthesize chemicals with N,N-dimethylamine group,which has promising applications for N-containing chemicals synthesis.

Asymmetric polymerase chain reaction and loop-mediated isothermal amplification(AP-LAMP) for ultrasensitive detection of microRNAs

In this manuscript,we first report an ultrasensitive detection assay of microRNA by combing asymmetric polymerase chain reaction(A-PCR)and loop-mediated isothermal amplification(LAMP)technology.Using A-PCR obtained an extended single strand to form LAMP stem-loop structure under isothermal amplification conditions.We used miRNAs as a loop primer probe in LAMP reaction and completed its ultrasensitive and rapid detection.The established method furnished a fast,specific and efficient detection of target miRNA with a detection limit as low as 10 amol/L in 90 min.

Flexible substrates enabled highly integrated patterns with submicron precision toward intrinsically stretchable circuits

Fabricating high integration density,high resolution,and intrinsically stretchable patterns by patterned technologies remain challenging.Template printing enabled high-precision patterned fabrication at a facile operation.However,the pattern spacing constraint is the major limitation to high integration density.In this study,we develop an elastomer-assisted strategy to improve the template printing process,which involves patterning on the prestrain elastic substrate.This strategy overcomes the spacing limitation and enables the realization of a centimeter-scale pattern with submicron precision.Particularly,the integration density of fabricated intrinsically stretchable patterns can reach 1932 lines on a substrate of 0.5 cm2;the assembly lines with a feature size of 880 nm and an interval of 955 nm.Furthermore,we demonstrate a facile approach for constructing silver nanoparticle/liquid metal alloy composite conductive patterns.The as-prepared flexible electrodes can withstand up to 150%strain and a 2-mm bend radius.This method provides new insights into template printing technology.Additionally,it opens a route for the simultaneous construction of functional patterned arrays with large scale,high integration density,and intrinsic stretchability,which will be useful for the integrated fabrication of various flexible electronic devices.