Electrochemical capacitors (ECs) have been widely applied in electronics, electric vehicles, aircrafts, energy storage devices, uninterrupted or emergency power supplies, and so on. An ideal EC should have high energy and/or powder density, good rate capability, and long cycling life. Recently, graphene, graphene derivatives, and their composites have been explored as the electrode materials of ECs to satisfy these requirements. In this Perspective, we review the recent development in synthesizing graphene materials for ECs and discuss the strategies of fabricating graphene-based macroscopic electrodes. Particularly, we highlight the importance of the specific surface area, conductivity, and heteroatom-doping of graphene sheets and the micro/nanostructures of their electrodes for controlling the performances of graphene-based ECs.

This study demonstrates an all-region-applicable moist-electric generator (MEG) based on a highly hydrophilic graphene oxide composite, delivering considerable electric energy over a wide temperature (−25 °C to 50 °C) and relative humidity range (RH, 5–95%).

The rapidly growing demand for wearable and portable electronics has driven the recent revival of flexible Zn‐ion batteries (ZIBs). However, issues of dendrite growth and low the flexibility of Zn metal anode still impede their practical application. Herein, 3D nitrogen‐doped vertical graphene nanosheets in situ grown on carbon cloth (N‐VG@CC) are proposed to enable uniform Zn nucleation, thereby obtaining a dendrite‐free and robust Zn anode. The introduced zincopilic N‐containing groups in N‐VG effectively reduce the Zn nucleation overpotential by enhancing the interaction between Zn2+ ion and carbon substrate, as confirmed by density functional theory calculations, thus achieving uniform distribution of Zn nucleus. Moreover, the 3D nanosheet arrays can homogenize electric distribution, which optimizes the subsequence Zn deposition process and realizes the highly reversible Zn plating/stripping process. Consequently, the as‐prepared Zn@N‐VG@CC anode exhibits an improved overall electrochemical performance compared with Zn@CC. As a proof‐of‐concept application, the high‐performance Zn@N‐VG@CC electrodes are successfully employed as anodes for coin and flexible quasi‐solid‐state ZIBs together with MnO2@N‐VG@CC (deposited MnO2 nanosheets on N‐VG@CC) as cathodes. More importantly, the flexible ZIB exhibits impressive cycling stability with 80% capacity retention after 300 cycles and outstanding mechanical flexibility, indicating a promising potential for portable and wearable electronics.

Bending modulus of exfoliation-made single-crystalline hexagonal boron nitride nanosheets (BNNSs) with thicknesses of 25-300 nm and sizes of 1.2-3.0 microm were measured using three-point bending tests in an atomic force microscope. BNNSs suspended on an SiO(2) trench were clamped by a metal film via microfabrication based on electron beam lithography. Calculated by the plate theory of a doubly clamped plate under a concentrated load, the bending modulus of BNNSs was found to increase with the decrease of sheet thickness and approach the theoretical C(33) value of a hexagonal BN single crystal in thinner sheets (thickness<50 nm). The thickness-dependent bending modulus was suggested to be due to the layer distribution of stacking faults which were also thought to be responsible for the layer-by-layer BNNS exfoliation.

The recent advance of p‐type transparent conductive oxide thin films is reviewed. The focus is on p‐type transparent oxide semiconductors CuAlO2, CuGaO2, CuInO2, SrCu2O2, and LaCuOCh (Ch = chalcogen). These materials and related device applications are then shown as examples. Room temperature operation of current injection emission from ultraviolet light‐emitting diodes based on p‐SCO/n‐ZnO p–n junctions has been demonstrated. This changed with the discovery of p‐type transparent conducting oxides, thereby opening up the possibility for all‐oxide transparent electronics. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)