Hierarchical porous carbon/graphene (HPC/HPG) materials have been intensively investigated over the past decades. These materials are demonstrated as promising electrode materials for various systems, such as lithium-ion batteries, lithium-sulfur batteries, supercapacitors, and fuel cells, with a remarkable capacity, high efficiency, long stability, and excellent rate capability. Researchers have now proposed the employment of hierarchical porous calcium oxide (CaO) particles as effective catalytic template for the facile CVD growth of graphene.
Due to the high concentration of silica in rice husks, most of the present research focuses on the preparation of silicon-based materials, which exhibit broad applications in the fields of adsorption, catalysis, energy storage, etc. There is also a large amount of organic components in rice husks, which is typically wasted in the preparation of these silica materials. Researchers now have developed an advanced method for the comprehensive use of rice husks. They fabricated high quality graphene quantum dots from the organic components of rice husks, and simultaneously obtained mesoporous silica nanoparticles with a high surface area from the inorganic content.
A scientist has discovered a previously unknown three-dimensional nanostructure consisting of graphene sheets. Graphene is a single monolayer of carbon atoms forming a hexagonal two-dimensional crystal lattice. The discovered nanostructure is a multilayer system of parallel hollow channels with quadrangular cross-section extending along the surface. The discovered nanostructure looked so extraordinary that it took some time to understand what it actually was. The structure was dramatically different from whatever had previously been observed on graphite.
Adding to the options for wirelessly powering implants from outside the body, researchers are proposing a light-driven powering device using near infrared rays (nIR). Flashing light impulses, which are absorbed by the device, induce temperature fluctuation, thus generating voltage/current pulses which can be used for charging a battery or biological stimulations. This flexible and compact device can generate electrical pulses with controllable amplitude and width when remotely irradiated by nIR. Not only can it supply power to implantable bioelectronics, but it also provides adjustable electrical pulses for nerve stimulation.
The complexity of the microenvironment of a biological cell is influenced by many factors, including surface topography and chemistry; matrix stiffness; mechanical stress; molecular liquid composition and other physiochemical parameters. However, most artificial biointerfaces are developed based on just a single chemical or physical factor to direct cell behaviors. The functions performed by these artificial biointerfaces are far simpler than those performed in the natural cell microenvironment. In an effort to more closely mimic a cell's natural environment, researchers have fabricated an antibody modified reduced graphene oxide platform and used it to significantly improve the efficiency for capturing circulating tumor cells.
Given the huge economic incentives, corrosion prevention and protection is a major business. The advanced materials that are being developed and used in modern industries require increasingly sophisticated coatings for improved performance and durability. Take for example the case of microbially induced corrosion (MIC) - one of the lesser understood forms of corrosion where micro-organisms manifest metallic surfaces and induce substantial damage that often goes unnoticed until there is a loss in the component functionality. New research features graphene as a promising novel surface coating that can be used to minimize metallic corrosion under harsh microbial conditions.
A carbon material with high electrical conductivity, high specific surface area, tunable pore structure, mechanically robust framework, and high chemical stability is an important requirement for advanced electrochemical energy storage. However, neither porous carbon or sp2 carbon can full meet these requirements yet. How to create a conductive carbon material with especially large pore volume, and hence large surface area, has therefore been a key focus in electrode research.
Synthesis of holey two-dimensional (2D) nanosheets with defined hole morphology and hole edge structures remains a great challenge for graphene. It is also an issue for other 2D nanomaterials, such as hexagonal boron nitride (h-BN) and molybdenum disulfide. In new work, researchers have reported a facile, controllable, and scalable method to carve geometrically defined pit/hole shapes and edges on h-BN basal plane surfaces via oxidative etching in air using silver nanoparticles as catalysts.