The electrochemical behaviors of single-, few- and multi-layer graphene, graphene oxides, reduced graphene oxides, CVD graphene and three-dimensional graphene are discussed and critically evaluated, ...providing an up-to-date summary on the progress of the field.
•The electrochemistry of single-, few- and multi-layer graphene•The electrochemistry of graphene oxides, reduced graphene oxides•The electrochemistry of CVD graphene and three-dimensional graphene
Two dimensional (2D) materials exhibit highly useful materials properties. Graphene, single sheet transition metals dichalcogenides found plethora applications in various fields, including analytical ...chemistry. Layered black phosphorus and its single sheet variation (phosphorene) became popular material very recently due to its monoelemental composition, biocompatibility, electrochemical properties, tunable bandgap and resulting optical properties. Here we describe progress which was made towards analytical applications of black phosphorus and its single sheet counterpart, phosphorene.
•Layered black phosphorus and phosphorene show biocompatibility.•Phosphorene has interesting electrochemical properties, optical properties and tunable bandgap.•The analytical applications of black phosphorus are overviewed.
This Perspective illustrates how impurities in nanomaterials affect their electrocatalytic properties. The focus is on 1D and 2D nanomaterials, starting with carbon nanotubes, through graphene and ...transition metal dichalcogenides to black phosphorus, and closing the circle with graphene in 3D-printed materials. Through these examples, we show that detailed materials characterization is paramount prior to assigning catalytic properties to specific functionality. We show that while metallic impurities in nanocarbons and black phosphorus are often a source of perceived electrocatalysis of these materials, the different phase and valency impurities are often sources of electrocatalysis in transition metal dichalcogenides. These impurities should not be viewed negatively because if their amount is controlled, then they become dopants and can be beneficial for the intended applications of these nanomaterials.
Electrocatalytic or not? Carbon nanotubes (CNTs; see figure) are at the forefront of electrochemical research, but care should be taken when describing the electrochemistry, which is often caused by ...defects or impurities. A discussion on this aspect of their chemistry as well as important applications of CNTs for sensing and energy storage are presented.
Carbon nanotubes (CNTs) are in the forefront of electrochemical research. It has become clear that an understanding of the fundamental reasons for the electrochemical activity of CNTs is essential for further progress in the field. This review provides a critical discussion of the fundamental reasons behind the electrochemical and “electrocatalytic” activity of CNTs as well as on important applications of CNTs for sensing, biosensing, and energy storage systems.
Electrocatalytic or not? Carbon nanotubes (CNTs; see figure) are at the forefront of electrochemical research, but care should be taken when describing the electrochemistry, which is often caused by defects or impurities. A discussion on this aspect of their chemistry as well as important applications of CNTs for sensing and energy storage are presented.
While the electrochemistry of redox-active ions or molecules has been studied for decades, the electrochemistry of individual nanoparticles remains largely unexplored. In this issue of ACS Nano, ...Stuart et al. report the direct electrochemical detection of impacting carbon C60 nanoparticles in a non-aqueous solution. This study opens up the possibility of detecting and counting various redox-active inorganic, organic, and carbon-based nanoparticles, one by one, in colloids and suspensions by a simple and highly sensitive technique. The method developed by Stuart et al. enables the determination of the type, size, and concentration of the nanoparticles. One can foresee a wide scope of potential applications, ranging from the environmental monitoring of nanoparticles to the detection of self-propelled autonomous nano- and micromachines.
Since its conception during the 80s, 3D-printing, also known as additive manufacturing, has been receiving unprecedented levels of attention and interest from industry and research laboratories. This ...is in addition to end users, who have benefited from the pervasiveness of desktop-size and relatively cheap printing machines available. 3D-printing enables almost infinite possibilities for rapid prototyping. Therefore, it has been considered for applications in numerous research fields, ranging from mechanical engineering, medicine, and materials science to chemistry. Electrochemistry is another branch of science that can certainly benefit from 3D-printing technologies, paving the way for the design and fabrication of cheaper, higher performing, and ubiquitously available electrochemical devices. Here, we aim to provide a general overview of the most commonly available 3D-printing methods along with a review of recent electrochemistry related studies adopting 3D-printing as a possible rapid prototyping fabrication tool.
3D printing (also called "additive manufacturing" or "rapid prototyping") is able to translate computer-aided and designed virtual 3D models into 3D tangible constructs/objects through a ...layer-by-layer deposition approach. Since its introduction, 3D printing has aroused enormous interest among researchers and engineers to understand the fabrication process and composition-structure-property correlation of printed 3D objects and unleash its great potential for application in a variety of industrial sectors. Because of its unique technological advantages, 3D printing can definitely benefit the field of microrobotics and advance the design and development of functional microrobots in a customized manner. This review aims to present a generic overview of 3D printing for functional microrobots. The most applicable 3D printing techniques, with a focus on laser-based printing, are introduced for the 3D microfabrication of microrobots. 3D-printable materials for fabricating microrobots are reviewed in detail, including photopolymers, photo-crosslinkable hydrogels, and cell-laden hydrogels. The representative applications of 3D-printed microrobots with rational designs heretofore give evidence of how these printed microrobots are being exploited in the medical, environmental, and other relevant fields. A future outlook on the 3D printing of microrobots is also provided.
3D printing can enable the customized design and fabrication of microrobots for a wide range of functional applications.
The chemical reduction of graphene oxide is a promising route towards the large scale production of graphene for commercial applications. The current state-of-the-art in graphene oxide reduction, ...consisting of more than 50 types of reducing agent, will be reviewed from a synthetic chemistry point of view. Emphasis is placed on the techniques, reaction mechanisms and the quality of the produced graphene. The reducing agents are reviewed under two major categories: (i) those which function according to well-supported mechanisms and (ii) those which function according to proposed mechanisms based on knowledge of organic chemistry. This review will serve as a valuable platform to understand the efficiency of these reducing agents for the reduction of graphene oxide.
Current state-of-the-art in graphene oxide reduction, consisting of more than 50 types of reducing agent, is reviewed from a synthetic chemistry viewpoint.
The recent advances in the micro/nanomotor field have shown great progress in the propulsion of such devices by fuel-free mechanisms. Light, as an abundant and natural source, has been demonstrated ...to be a promising external field to wirelessly induce the motion of these tiny micro/nanomachines, without the need of any toxic fuel or complex system set-up. This tutorial review covers the most representative examples of light-driven micro/nanomotors developed so far, which self-propelled exclusively under fuel-free conditions. Their different swimming behaviors triggered by light stimuli, divided into four main categories (schooling, phototaxis, gravitaxis and directional motion), are discussed along with their similarities with the motion modes of microorganisms. Moreover, the main parameters that influence the motion of light-driven photocatalytic-based micro/nanomotors as well as alternative strategies to develop more efficient systems are also discussed.
This review covers the main examples of fuel-free light-driven micro/nanomotors and their different swimming styles, highlighting the most important parameters to consider when designing photocatalytic-based devices with a high propulsion efficiency.
