2D layered transition metal dichalcogenides (TMDCs) have emerged as new possibilites beyond conventional particulate catalysts in facilitating efficient electrochemical hydrogen evolution. This is mainly mediated by the ultrahigh surface-to-volume ratio and the effective coupling of all active sites with supporting electrodes. Especially, the facile chemical vapor deposition (CVD) method has enabled morphological engineering of monolayer TMDC catalysts toward development of abundant active edge sites within the 2D plane. Here, two pathways to achieve such purpose are highlighted, either by non-equilibrium growth of MoS₂ dendrites or throughout high-density nucleation of MoS₂ nanoflakes directly on the electrode materials. Furthermore, future research directions have also been proposed and discussed to further enhance the efficiency of such unique catalysts.

Aligned, ultralong single-walled carbon nanotubes (SWNTs) represent attractive building blocks for nanoelectronics. The structural uniformity along their tube axis and well-ordered two-dimensional architectures on wafer surfaces may provide a straightforward platform for fabricating high-performance SWNT-based integrated circuits. On the way towards future nanoelectronic devices, many challenges for such a specific system also exist. This Review summarizes the recent advances in the synthesis, identification and sorting, transfer printing and manipulation, device fabrication and integration of aligned, ultralong SWNTs in detail together with discussion on their major challenges and opportunities for their practical application.

Single-walled carbon nanotubes (SWNTs), as one of the most promising one-dimension nanomaterials due to its unique structure, peculiar chemical, mechanical, thermal, and electronic properties, have long been considered as an important building block to construct ordered alignments. Vertically aligned SWNTs (v-SWNTs) have been successfully prepared by using direct growth and chemical assembly strategies. In this review, we focus explicitly on the v-SWNTs fabricated via chemical assembly strategy. We provide the readers with a full and systematic summary covering the advances in all aspects of this area, including various approaches for the preparation of v-SWNTs using chemical assembly techniques, characterization, assembly kinetics, and electrochemical properties of v-SWNTs. We also review the applications of v-SWNTs in electrochemical and bioelectrochemical sensors, photoelectric conversion, and scanning probe microscopy.

Universal strategies for synthesizing one-dimensional organic nanomaterials are of fundamental importance in the development of more flexible, cheaper and lighter electronics. Charge-transfer (CT) complexes, the major kind of organic conductors, are in the long-term attractive materials owing to their unique crystal structures and conductive properties. In this article, a general strategy for the synthesis of CT complex micro/nanowires based on the localized nanoelectrochemistry using tiny carbon nanotube (CNT) electrodes is presented. This strategy is successfully demonstrated over 12 typical CT complexes, and a general rule for the preparation of various kinds of CT complex micro/nanowires is summarized. The CT complex micro/nanowires thus synthesized have high aspect ratios and long lengths as compared with traditional macroscopic planar electrodes, originating from the one-dimensional structural feature with fewer or no defects and the ultrasmall surface area of the CNT. This work provides a more versatile material basis for the fundamental and application studies of low-dimensional organic conductor materials.

Graphene behaves as a robust semimetal with the high electrical conductivity stemming from its high-quality tight two-dimensional crystallographic lattice. It is therefore a promising electrode material. Here, a general methodology for making stable photoresponsive field effect transistors, whose device geometries are comparable to traditional macroscopic semiconducting devices at the nanometer scale, using cut graphene sheets as 2D contacts is detailed. These contacts are produced through oxidative cutting of individual 2D planar graphene by electron beam lithography and oxygen plasma etching. Nanoscale organic transistors based on graphene contacts show high-performance FET behavior with bulk-like carrier mobility, high on/off current ratio, and high reproducibility. Due to the presence of photoactive molecules, the devices display reversible changes in current when they are exposed to visible light. The calculated responsivity of the devices is found to be as high as ∼8.3 A W⁻¹. This study forms the basis for making new types of ultrasensitive molecular devices, thus initiating broad research interest in the field of nanoscale/molecular electronics.