Phosphorus Dual-doped Graphene Research Articles

Synthesis of Nitrogen and Phosphorus Dual-Doped Graphene Oxide as High-Performance Anode Material for Lithium-Ion Batteries.

Nitrogen and phosphorus dual-doped graphene oxide was prepared by directly calcining a mixture of pure graphene oxide, urea (nitrogen source), and 1,2-bis(diphenylphosphino)methane (phosphorous source). The morphology and composition of the obtained dual-doped graphene oxide were confirmed by SEM, TEM, XRD pattern, Raman spectrum, and XPS. The nitrogen and phosphorous dual-doped graphene oxide was tested as an anode material of lithium-ion batteries (LIBs). The cycle and rate performance of the dual-doped graphene oxide were also examined. The dualdoped graphene oxide exhibited a superior initial discharge capacity of 2796 mAh·g-1 and excellent reversible capacity of 1200 mAh·g-1 at a current density of 100 mA·g-1 after 200 charge/discharge cycles, suggesting that the dual-doping of nitrogen and phosphorous is an effective way to enhance lithium-ion storage for graphene oxide.

Controllable synthesis of CoNb2O6 nanoparticles on multifunctional sulfur and phosphorus dual-doped graphene as advanced electrodes for hybrid supercapacitors

Battery type hybrid supercapacitors have drawn more attention as a great potential storage device with both excellent rate capability and high energy densities. Herein, we demonstrate a facile hydrothermal method to the preparation of sulfur and phosphorus atoms co-doping into the graphene nanosheet (SPG) using sulphuric acid and phytic acid as dopant. The NbCo precursor could be uniformly dispersed in SPG by formation of coordination bonds with the six phosphate groups of phytic acid. Morphological characteristic indicate that the CoNb2O6 nanoparticles grown directly on three-dimensional SPG framework (CoNb2O6/SPG) through high temperature calcination. As battery-type hybrid supercapacitors equipment, the asymmetric device consisting of CoNb2O6/SPG hybrids and active carbon (AC) delivers remarkable cycling stability (92.5% of the initial after 10,000 charge and discharge cycles) and outstanding rate capability (73.9% retention from 0.5 to 4 A g−1). More remarkably, the above device exhibits an impressive energy density of 39.7 Wh kg−1 at a high power density of 2995 Wkg-1. This outstanding performance is mainly ascribed to the large surface area and highly conductive of S and P co-doped 3D graphene architecture, the uniformly distributed and highly exposed CoNb2O6 nanoparticles and the incorporating effects with them.

Surface modulated hierarchical graphene film via sulfur and phosphorus dual-doping for high performance flexible supercapacitors

Graphene surface modification by heteroatom incorporation is an attractive strategy to construct flexible electrochemical capacitors. Herein, the steam-assistant heteroatoms of sulfur and phosphorus dual-doped graphene film (s-SPG) is fabricated via an ice-template and thermal-activation approach and they demonstrate an excellent pseudocapacitive behavior in flexible electrochemical capacitors. As probed by various microscopic and spectroscopic analysis, well-maintained porosity structure is formed during the freeze-drying and steam-activation treatment; the increased surface roughness is ascribed to heteroatoms doping by the formation of S- and P-containing functional groups as electrochemical active sites. A flexible device integrated by porous s-SPG film shows high pseudocapacitive behavior with high specific capacitance (169 F/g), rate capability (91.7%) and cyclic stability (92.5%). Even at the bend angle of 120°, no obvious change of specific capacitance is found indicating a good flexibility of s-SPG devices; the current study shows that s-SPG is a very promising electrode to realize the practical applications of all solid flexible supercapacitors.

Nitrogen and Phosphorus Dual-Doped Graphene Aerogel Confined Monodisperse Iron Phosphide Nanodots as an Ultrafast and Long-Term Cycling Anode Material for Sodium-Ion Batteries

Transition metal phosphides have recently gained much interest as anodes for sodium-ion batteries (SIBs). However, their intrinsic volume change during Na ion uptake/release leads to poor cycling s...

Mechanisms of direct hydrogen peroxide synthesis on silicon and phosphorus dual-doped graphene: a DFT-D study.

Hydrogen peroxide (H2O2) is an important chemical commodity, with demand growing significantly in chemical synthesis due to its green characteristics. The mechanisms of the direct synthesis of hydrogen peroxide (DSHP) on metal-free silicon and phosphorus dual-doped graphene (Si-P-G) catalyst, based on a dispersion-corrected density functional theory (DFT-D) method, are systematically investigated. The most stable Si-P-G catalyst is presented, with the local region of dopants shown to play an important role in the adsorption and reduction of oxygen. A two-electron pathway is probable for DSHP on Si-P-G according to kinetic and thermodynamic analyses. The hydrogenation of O2 to OOH is the rate-limiting step, with a small barrier energy of 0.66 eV, and the potential energy surface is downhill by Gibbs free energy calculations. All results indicate that Si-P-G is a novel catalyst with high activity and good selectivity for DSHP.

Nitrogen and phosphorus dual-doped graphene as a metal-free high-efficiency electrocatalyst for triiodide reduction.

Alternative high-performance electrocatalysts for triiodide (I3-) reduction of low-cost dye-sensitized solar cells (DSSCs) are urgently sought after. To address the concerned issues, we report a facile strategy for engineering the nitrogen and phosphorus dual-doped graphene (NPG) via an efficient ball-milling process, followed by a simple thermal annealing approach utilizing melamine (C3H6N6) and triphenylphosphine ((C6H5)3P) as the N and P source, respectively. When employed as the counter electrode (CE) in DSSCs, such a metal-free material exhibits excellent electrocatalytic activity towards the I3-/I- redox reaction. Dual-doping of N and P heteroatoms can markedly enhance the photovoltaic performance of DSSCs by a synergistic effect and a high conversion efficiency of 8.57% is achieved, which is superior to Pt CE, and much higher than that of the single-component N- or P-doped graphene electrodes. In addition, the NPG CE also shows an outstanding electrochemical stability. The present results demonstrate that the NPG as a low-cost and high-efficiency electrocatalyst for reduction of I3- will be one of the promising CE materials in DSSCs.