Abstract Microporous activated carbon originating from coconut shell, as received or oxidized with nitric acid, is treated melamine and urea heated to 950 °C in an inert atmosphere modify the surface nitrogen‐ oxygen‐containing groups for a systematic investigation of their combined effect on electrochemical performance 1 M H 2 SO 4 supercapacitors. The chemistry samples characterized using elemental analysis, Boehm titration, potentiometric X‐ray photoelectron spectroscopy. Sorption...

Abstract Nitrogen‐enriched nonporous carbon materials derived from melamine–mica composites are subjected to ammonia treatment further increase the nitrogen content. For samples preoxidized prior treatment, content is doubled and mainly incorporated in pyrrol‐like groups. The tested as electrodes for supercapacitors, acidic or basic electrolytes, gravimetric capacitance of treated three times higher than that untreated samples. This represents a tenfold per surface area (3300 µF cm −2 )...

Honeycomb catalysis: a facile oxygen reduction reaction has been observed on graphitic C(3)N(4)/carbon catalyst with three-dimensional interconnected macropores (see picture SiO(2) template). This material not only shows catalytic activity that is comparable to of commercial Pt/C, but also much higher organic-fuel tolerance and long-term stability.

Phosphorus-rich microporous carbons (P-carbons) prepared by a simple H(3)PO(4) activation of three different carbon precursors exhibit enhanced supercapacitive performance in 1 M H(2)SO(4) when highly stable can be achieved at potentials larger than the theoretical decomposition potential water. This ability P-carbons greatly enhances energy density supercapacitors that are capable delivering 16 Wh/kg compared to 5 for commercial carbon. An intercept-free multiple linear regression model...

Abstract Phosphorus‐doped (P‐doped) graphene with the P doping level of 1.30 at % was synthesized by annealing mixture and phosphoric acid. The presence confirmed elemental mapping X‐ray photoelectron spectroscopy, while morphology P‐doped revealed using scanning electron microscopy transmission microscopy. To investigate effect doping, electrochemical properties were tested as a supercapacitor electrode in an aqueous electrolyte 1 M H 2 SO 4 . results showed that exhibited significant...

Abstract Phosphorus‐rich carbons (PCs) were prepared by phosphoric acid activation of waste coffee grounds in different impregnation ratios. PCs characterized nitrogen and carbon dioxide adsorption X‐ray photoelectron spectroscopy. The results indicate that the step not only creates a porous structure, but also introduces various phosphorus oxygen functional groups to surface carbons. As evidenced cyclic voltammetry, galvanostatic charge/discharge, wide potential window tests, supercapacitor...

Vanadium nitride (VN) is currently one of the most promising materials for electrodes supercapacitors. The structure and electrochemical properties VN synthesized by temperature-programmed NH3 reduction V2O5 are analyzed in this paper. produced via route has distinctive structural characteristics. mimics shape initial precursor indicating a pronounced direct attachment grains. particles have domains grains with preferential orientation (texture). large volume pores represented range 15−110...

Honigwabenkatalyse: Einfach lässt sich Sauerstoff auf einem graphitischen C3N4/Kohlenstoff-Katalysator mit dreidimensionalen verbundenen Makroporen (im Bild SiO2 als Templat gezeigt) reduzieren. Dieses Material ist nicht nur katalytisch ähnlich aktiv wie kommerzielles Pt/C, sondern zudem toleranter gegenüber organischen Brennstoffen und hat eine höhere Langzeitstabilität. Detailed facts of importance to specialist readers are published as "Supporting Information". Such documents...

A copper oxide/nitrogen-doped reduced graphene oxide (CuO/N-rGO) nanocomposite is synthesized through a low-temperature aqueous process. The resultant characterized by spectroscopies which show significant interaction between and nitrogen. Electrochemical tests that the exhibits superior oxygen reduction (ORR) activity, significantly higher than of both N-rGO CuO/GO, close to commercial Pt/C. Further mechanistic study confirms enhancement ORR activity prompted synergistic effect nitrogen,...

Abstract The co‐doping of heteroatoms has been regarded as a promising approach to improve the energy‐storage performance graphene‐based materials because synergetic effect heteroatom dopants. In this work, single precursor melamine phosphate was used for first time synthesise nitrogen/phosphorus co‐doped graphene (N/P‐G) monoliths by facile hydrothermal method. nitrogen contents 4.27–6.58 at % and phosphorus levels 1.03–3.00 could be controlled tuning mass ratio oxide in precursors. N/P‐G...

Activated carbons with large mesopore volumes were prepared from waste coffee grounds by chemical activation ZnCl2. These exhibited excellent electrochemical double-layer capacitance of up to 368 F g−1 in 1 M H2SO4. The effect carbonization temperature and ZnCl2 ratio on carbon pore development consequently H2SO4 is discussed. Cyclic voltammetry, impedance spectroscopy, galvanic charge−discharge cycles used study the effects mesopores at fast charge rates. greater content retained higher...

Li-rich layered materials as promising high-energy cathode candidates have attracted much attention in recent years for next generation lithium ion batteries.

Abstract Well‐confined elemental sulfur was implanted into a stacked block of carbon nanospheres and graphene sheets through simple solution process to create new type composite cathode material for lithium–sulfur batteries. Transmission electron microscopy mapping analysis confirm that the as‐prepared consists graphene‐wrapped with uniformly distributed in between, where act as carriers. With this structural design, contributes direct coverage inhibit mobility polysulfides, whereas...