Nanopores in carbon nitride nanotubes: Reversible hydrogen storage sites

Abstract

Experimental and theoretical approaches are used to determine hydrogen storage mechanisms in nanopores of multiwalled carbon nitride nanotubes ͑MWCNNTs͒. First, the authors produce ϳ0.6 nm pores on the stems of MWCNNTs by plasma-enhanced chemical vapor deposition. Next, thermal desorption spectra were measured and obtained two different peaks. This is explained by hydrogen desorption barriers of 0.36-0.50 eV attributed to two different types of ϳ0.6 nm pores. Moreover, H 2 adsorption between complete interlayers is found to be endothermic by 1.27 eV. In this respect, open channels and ϳ0.6 nm pores on MWCNNTs are considered to provide the route for reversible hydrogen storage.

Studies of Physical and Chemical Properties of Two-Dimensional Hexagonal Crystals by First-Principles Calculation

“…Despite the fact that there are as yet no experimental reports on the last four 2D phases, the present result of 2D Ge facilitates the study of the trend of property variation among the three group IV elementary 2D phases. Besides, carbon nitride, 26) silicon nitride, 27) and silicon carbide are among the popular artificial materials for synthesis investigation nowadays. Success in fabrication of nanotubes or nanorods of CN 26) and SiN 27) has been reported experimentally.…”

“…Besides, carbon nitride, 26) silicon nitride, 27) and silicon carbide are among the popular artificial materials for synthesis investigation nowadays. Success in fabrication of nanotubes or nanorods of CN 26) and SiN 27) has been reported experimentally.…”

Fabrication of size-controlled Co nanoparticles via mediation of H-adatoms on pyridine-like nitrogen of carbon nitride nanotubes and their superior catalytic performance for hydrogen generation

“…N1, N2 and N3 indicate pyridine-like nitrogen, graphite-like nitrogen, and gaseous nitrogen molecules encapsulated in the core tube, respectively. 8 These nitrogen configurations act as defect sites, which bind the Co NPs on the CNNTs.…”

“…[5][6][7] Our previous studies demonstrated that carbon nitride nanotubes (CNNTs) including heterogeneous nitrogen in the carbon network would also be a promising host structure to provide the sites for anchoring metal NPs. 8,9 CNNTs have the great advantage of not needing an additional functionalization process, damaging the pristine structure of the CNNTs unlike the oxidative treatment of CNTs. In addition, the binding energy of metal atoms with CNNTs is larger than that for the pristine structure of CNTs, so they contribute to distribute the metal NPs more uniformly.…”

Spectroscopic Study of Plasma Polymerized a-C:H Films Deposited by a Dielectric Barrier Discharge

“…Hydrogenated carbon films are frequently classified into four classes: polymer-like films with the highest hydrogen content of up to 50% and up to 60% of hydrogen-terminated sp 3 bonds, diamond-like films with an intermediate H content (about 30%) and a large fraction of C–C sp 3 bonds, hydrogenated tetrahedral carbon films (ta-C:H) with a typically hydrogen content of 25% and the highest sp 3 content of about 70%, and graphite-like films with low hydrogen (<20%) but large sp 2 contents [ 6 ]. Due to these properties, hydrogenated carbon films can be used for super-hard materials [ 1 ], biomaterials [ 7 ], wear-resistant coatings [ 8 ], optical coatings [ 9 ], field enhanced conductors [ 10 ], smart polymer and biopolymer films [ 11 , 12 ], and hydrogen storage devices [ 13 ]. Film characteristics can be suitably tailored for particular applications employing different deposition techniques and precursor gas mixtures, e.g., chemical vapor deposition (CVD) [ 14 ], sputtering [ 15 ], plasma enhanced chemical vapor deposition (PECVD) [ 16 ], and pulsed laser deposition (PLD) [ 17 ].…”