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Due to their high spatial utilization, excellent flexibility and good adaptability, fiber‐shaped devices have promising potential for applications in wearable electronics. However, the fiberization process of the component with alternate current (AC) line filtering function is still far from being satisfactory, since it is difficult to arrange an ordered structure in a fiber shape in large‐scale manufacturing. This leads to a slow frequency response. Herein, a weavable fiber‐shaped electrochemical capacitor (SC) for AC line filtering is made of reduced graphene oxide (rGO) fibers with a highly oriented porous structure by wet‐spinning method. The highly consistent orientations of the rich pores greatly improve the ionic accessible sites, ion mobility and the electron transport pathways. As a result, the all‐fiber‐based SC revealing a high rate performance (500 V s−1) and a fast frequency response (RC time constant ∼0.241 ms, phase angle ∼−80°) is successfully applied to filter ±1.5 V AC to 1.04 V direct current (DC). Notably, the highly flexible SC exhibits an outstanding consistency during the performance test at bending and folding states. This work shows a potential substitution for aluminium electrolytic capacitors (AEC) towards wearable electronic. With every fiber of its being: a reduced graphene oxide fiber is continuously synthesised on large scale in an ordered structure using a wet spinning method. The wet spun reduced graphene oxide fiber is fabricated for fiber‐shape supercapacitors and applied in AC line filtering. The fiber‐shape supercapacitors can be woven and exhibit good filtering performance for some waveforms, such as Gaussian, sawtooth wave etc. [ABSTRACT FROM AUTHOR]

In this paper, we fabricate a flexible elastic carbon foam (ECF)-based pressure sensor by direct carbonization of melamine foams (MF) at 800 °C without using any metal catalyst. The carbonized ECF is composed of a unique 3D interconnected concave triangular carbon network with a fraction of cracked carbon microfibers, and displays abundant micro and meso-porosity. We select the ECF as a sensing material due to its conductive and elastic features, and make a piezoresistive sensor with ultrahigh sensitivity (100.29 kPa−1) and reproducible sensing (11 000 cycles) characteristics. Moreover, the pressure sensor is able to distinguish a large pressure range from as low as 3 Pa to 10 kPa. The cheap raw materials, simple fabrication process and satisfactory performance of the pressure sensor make it a promising device for electronic monitoring systems in industrial detection, human motion monitoring and so on. [ABSTRACT FROM AUTHOR]

Herein, a vertical finger-like asymmetric supercapacitor (VFASC) comprising a reduced graphene oxide–manganese dioxide–polypyrrole (RGO–MnO2–PPy) positive electrode and reduced graphene oxide–molybdenum trioxide (RGO–MoO3) negative electrode was fabricated for the first time. The relationship between specific capacitance and mass loading of the VFASC was systematically studied. To our surprise, contrary to the general problem faced by supercapacitors, the specific capacitance of VFASC increased with an increase in the mass loading of the electrode. Furthermore, as the VFASC supplied a potential and MoO3 guaranteed photodetection capacity, the VFASC also acted as a photodetector with excellent sensitivity for the detection of white light without the use of additional external connected systems. This study presents an essential strategy for the preparation of high performance supercapacitors with high mass loading, low production cost, energy efficiency, space saving and simple integrated photodetection systems. [ABSTRACT FROM AUTHOR]

The growth of nanocrystals has widely been researched recently through an in situ high‐resolution transmission electron microscopy technique, which reveals the process of morphological and structural evolutions. For nanocrystals, the underlying growth modes are mostly determined by growth environment and crystal morphology. Here, the direct growth process of the PbSe nanocrystals via controlling the temperature is clearly observed. The results show that the PbSe nanocrystals start growth following oriented attachment growth mode, and then change to growth with grain boundary migration at moderate temperature as the heat activated nanocrystals gather together with decreased degree of freedom for crystal rotation. During the grain boundary migration, the smaller nanocrystals are inclined to be assimilated by larger ones through interfacial atom reconfigurations, which are observed to take place through strain mediated atom migration. The growth mode changes in different growth states with a hybrid growth mode of oriented attachment and grain boundary migration during the whole growth process. [ABSTRACT FROM AUTHOR]

High-performance microsupercapacitors (MSCs) with three-dimensional (3D) structure provide an effective approach to improve the ability of energy storage. Because the electrodes with 3D structure are generally easily destroyed under mechanical deformation in practical applications, we fabricated a self-healable 3D MSC consisting of MXene (Ti 3 C 2 T x )-graphene (reduced graphene oxide, rGO) composite aerogel electrode by wrapping it with a self-healing polyurethane as an outer shell. The MXene-rGO composite aerogel combining large specific surface area of rGO and high conductivity of the MXene can not only prevent the self-restacking of the lamella structure but also resist the poor oxidization of MXene to a degree. The MSC based on a 3D MXene-rGO aerogel delivers a large area specific capacitance of 34.6 mF cm -2 at a scan rate of 1 mV s -1 and an outstanding cycling performance with a capacitance retention up to 91% over 15 000 cycles. The 3D MSC presents an excellent self-healing ability with specific capacitance retention of 81.7% after the fifth healing. The preparation of this self-healable 3D MSC can provide a method for designing and manufacturing next-generation long-life multifunctional electronic devices further to meet the requirements of sustainable development.

A piezoresistive sensor based on ultralight and superelastic aerogel is reported to fabricate MXene/reduced graphene oxide (MX/rGO) hybrid 3D structures and utilize their pressure-sensitive characteristics. The MX/rGO aerogel not only combines the rGO's large specific surface area and the MXene's (Ti 3 C 2 T x ) high conductivity but also exhibits rich porous structure, which leads to performance better than that of single-component rGO or MXene in terms of the pressure sensor. The large nanosheets of rGO can prevent the poor oxidization of MXene by wrapping MXene inside the aerogel. More importantly, the piezoresistive sensor based on the MX/rGO aerogel shows extremely high sensitivity (22.56 kPa -1 ), fast response time (<200 ms), and good stability over 10 000 cycles. The piezoresistive sensor based on the MX/rGO hybrid 3D aerogel can easily capture the signal below 10 Pa, thus clearly testing the pulse of an adult at random. Based on its superior performance, it also demonstrates potential applications in measuring pressure distribution, distinguishing subtle strain, and monitoring healthy activity.

SnO2 nanoparticles display a pseudo-negative-photoconductivity (PsdNPC) effect, which shows that their resistance increases under light irradiation via a heating effect. The PsdNPC originates from intensive electron scattering of the nanoamorphous surface state of the SnO2 nanoparticles, resulting in a small inner current and a large absorption of moisture, leading to a large surface current. Graphene as the inner skeleton can shorten the response and recovery times., (© 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)