Linköping researchers make progress in using graphene to make fuel from water and carbon dioxide

Researchers at Linköping University (LiU) in Sweden are working to develop a method to convert water and carbon dioxide to the renewable energy of the future, using the energy from the sun and graphene applied to the surface of cubic silicon carbide.

The LiU research group recently reported an important step towards achieving this goal, and developed a method that makes it possible to produce graphene with several layers in a tightly controlled process. They have also shown that graphene acts as a superconductor in certain conditions.

Read the full story Posted: Oct 31,2018

Researchers find the exact balance in which graphene coatings can promote hydrogen evolution reaction

A collaboration led by the University of Tsukuba has recently optimized an approach to increase the stability of catalysts used in the hydrogen evolution reaction without significantly sacrificing activity. The team found that coating catalyst nanoparticles with an optimal number of layers of graphene raised nanoparticle durability while allowing the nanoparticles to retain their catalytic activity. The study was reported in ACS Energy Letters.

"We optimized the balance between the number of graphene layers coating the nanoparticles and their catalytic activity," study first author Kailong Hu says. "To do this, we had to precisely control the number of graphene layers coating the nanoparticles, which we achieved by carefully regulating the deposition time of graphene on the nanoparticles."

Read the full story Posted: Jun 29,2018

Japanese team designs a graphene-based electrode that can produce hydrogen under acidic conditions

Researchers at the Japanese Tsukuba University described a graphene-based electrode that can produce hydrogen under acidic conditions. The electrolysis of water to generate hydrogen is vital for energy storage in a green economy. One of the major obstacles, however, is the high cost of noble-metal electrodes. Cheaper non-noble electrodes function well in driving the hydrogen evolution reaction (HER), but mainly in alkaline conditions, where the reaction is electricity-hungry. The more efficient acid-phase reaction requires precious metals such as platinum. Worse still, the acid electrolytes are corrosive and eat away at the core metal.

Perforated graphene for hydrogen production image

The researchers have found that holey graphene offers a way around this problem. They used nitrogen-doped graphene sheets to encapsulate a nickel–molybdenum (NiMo) electrode alloy. The graphene was punched full of nanometer-size holes. The researchers showed that in acid conditions, their HER system dramatically outperforms an electrode using regular non-holey graphene. The use of graphene in HER electrodes is not new—this flexible, conductive carbon sheet is ideal for wrapping around the core metal. However, although it protects the metal against corrosion, graphene also suppresses its chemical activity. In the Tsukuba system, the holes promote the reaction in two ways, while the intact graphene part protects the metal.

Read the full story Posted: May 13,2018

University of Warsaw team develops a graphene-matrix with potential for medicine and food applications

Researchers at the Department of Chemistry of the University of Warsaw in Poland have developed a new graphene matrix, as a functional substrate for immobilizing enzymes, and the method of its preparation. The newly-patented graphene matrix may find applications in the food and medicine industries, like the production of biosensors and other electronic devices (eg. bands, tattoos).

A graphene matrix for applications in the food industry and medicine for the production of biosensors imageDiagram of a lactate biosensor composed of a graphene matrix and a lactate oxidase enzyme, deposited on a carbon electrode

The invention is used as a stable system with high sensitivity, not only in analytical biosensors, but also in bio-fuel cells used in medicine, biology and chemical biocatalysis. The solution concerns the enzymatic (protein) sensor construction for detection of lactates, which can be used in the food industry and medicine for the production of biosensors.

Read the full story Posted: Apr 25,2018

XFNano graphene materials used in advanced energy application research

The following is a sponsored post by XFNano

XFNano's graphene materials were recently used in two fascinating research work focused on advanced energy applications.

NiCo-HS@G fabrication (XFNano)

The first is a work by teams from Anhui Normal University, Chinese Academy of Sciences (CAS) and the University of the Chinese Academy of Sciences which developed a fast, one-step strategy to prepare sandwiched metal hydroxide/graphene composites through a kinetically controlled coprecipitation under room temperature. Such NiCo-HS@G nano-composite exhibits good electrocatalytic activity for OER, superior to most of the reported OER catalysts. Such performance and the facile preparation of NiCo-HS@G opens up a new avenue for the cost-effective and low-energy-consumption production of various sandwiched metal hydroxides/graphene composites as efficient OER electrocatalysts with desired morphology and competing performance for the applications in diverse energy devices.

Read the full story Posted: Apr 16,2018

Graphene sheets and nickel turn CO2 into usable energy

Researchers at the U.S. Department of Energy’s (DOE) Brookhaven National Laboratory are part of a scientific collaboration that has identified a new electrocatalyst that efficiently converts CO2 to carbon monoxide (CO), a highly energetic molecule.

“There are many ways to use CO,” says Eli Stavitski, a scientist at Brookhaven and an author on the paper. “You can react it with water to produce energy-rich hydrogen gas, or with hydrogen to produce useful chemicals, such as hydrocarbons or alcohols. If there were a sustainable, cost-efficient route to transform CO2 to CO, it would benefit society greatly”. Indeed, scientists have been looking for a way to do just that, but traditional electrocatalysts can't effectively initiate the reaction. That’s because a competing reaction, called the hydrogen evolution reaction (HER) or “water splitting,” takes precedence over the CO2 conversion reaction.

Read the full story Posted: Mar 05,2018

Rice University team detects metal in ‘metal-free’ graphene catalysts

Rice University scientists, led by Prof. James Tour, along with teams from the University of Texas at San Antonio and the Chinese Academy of Sciences, Beijing, China have detected a deception in graphene catalysts that, until now, gone unnoticed. Graphene has been widely tested as a replacement for expensive platinum in applications like fuel cells, where the material catalyzes the oxygen reduction reaction (ORR) essential to turn chemical energy into electrical energy.

Rice team finds  manganese atoms in graphene catalysts image

Since graphene isn't naturally metallic, researchers have been baffled by its catalytic activity when used as a cathode. The Rice team has now discovered that trace quantities of manganese contamination from graphite precursors or reactants hide in the graphene lattice. Under the right conditions, those metal bits activate the ORR. Tour said they also provide insight into how ultrathin catalysts like graphene can be improved.

Read the full story Posted: Feb 27,2018

Proton transport in graphene may lead to renewable energy production

Researchers at The University of Manchester have found a new and exciting physical effect in graphene – membranes that could be used in devices to artificially mimic photosynthesis.

Graphene proton transport open door to renewable energy image

The new findings demonstrated an increase in the rate at which the material conducts protons when it is simply illuminated with sunlight. The 'photo-proton' effect, as it has been named, could be utilized to design devices able to directly harvest solar energy to produce hydrogen gas, a promising green fuel. It might also be of interest for other applications, such as light-induced water splitting, photo-catalysis and for making new types of highly efficient photodetectors.

Read the full story Posted: Jan 24,2018

New graphene-based catalyst for hydrogen production could be a step toward clean fuel

Researchers at UC Santa Cruz South and the China University of Technology have developed a graphene-based nanostructured composite material that shows impressive performance as a catalyst for the electrochemical splitting of water to produce hydrogen. An efficient, low-cost catalyst is essential for realizing the promise of hydrogen as a clean, environmentally friendly fuel.

The team has been investigating the use of carbon-based nanostructured materials as catalysts for the reaction that generates hydrogen from water. In a recent study, they obtained good results by incorporating ruthenium ions into a sheet-like nanostructure composed of carbon nitride. Performance was further improved by combining the ruthenium-doped carbon nitride with graphene, to form a layered composite.

Read the full story Posted: Jan 18,2018

Graphene to potentially replace platinum for cheaper fuel cells

Researchers from Rice University have discovered that nitrogen-doped carbon nanotubes or modified graphene nanoribbons could potentially replace platinum, one of the most expensive facets in fuel cells, for performing fast oxygen reduction—a crucial reaction that transforms chemical energy into electricity.

Graphene to replace platinum in fuel cells image

The researchers used computer simulations to see how carbon nanomaterials can be improved for fuel-cell cathodes and discovered the atom-level mechanisms by which doped nanomaterials catalyze oxygen reduction reactions. The simulations also revealed why graphene nanoribbons and carbon nanotubes modified with nitrogen and/or boron are so sluggish and how they can be improved.

Read the full story Posted: Jan 07,2018