Topochemical Intercalation of Graphitic Carbon Nitride with Alkali Metals in Ethylenediamine

Abstract

We studied the intercalation chemistry of graphitic carbon nitride (gCN), combining theory and experimental methods. A series of new alkali-ethylenediamine-gCN products were prepared using a one-pot topochemical synthesis method. Spectroscopic and thermal analyses showed t h a t s i n g l e -s t a g e i n t e r c a l a t e d g C N c o m p o u n d s o f L i -( e t h y l e n e d i a m i n e ) 0 . 2 ( C 3 N 4 . 5 H 1 . 5 ) 1 . 0 a n d N a -(ethylenediamine) 0.3 (C 3 N 4.5 H 1.5 ) 0.9 with ordered layer structures were formed. X-ray diffractograms indicated a large gallery expansion of 0.349 and ∼0.342 nm for Li-and Na-intercalated gCN. In the case of K-en-gCN, a nanocomposite was formed that underwent spontaneous in situ exfoliation followed by disordered restacking to form thin flakes. Molecular dynamics studies showed that ethylenediamine molecules were distributed at the center of the interlayer spaces, predominantly adopting a trans conformation. Different types of gallery sites were present for the intercalation of guest alkali metals, leading to a high degree of topochemical intercalation with organic entities under lower temperatures than previously reported in thermal intercalation experiments. Our new synthesis route enables facile intercalation to tune interlayer spacing in gCN.

Self-assembly of colloidal single-layer carbon nitride

“…The GCN intercalation as a preparatory step for exfoliation was reported for several intercalating species, including H 2 SO 4 , 20 ethylenediamine, 21 HCl, 22 NH 4 Cl, 23 and water. 24 The exfoliation of intercalates is facilitated due to a large increase of the interlayer distance (H 2 SO 4 , ethylenediamine), 20,21 decomposition of the intercalated compound to gaseous products (NH 4 Cl), 23 or a reaction with the GCN sheets releasing large volumes of gases (H 2 O). 24…”

g-C3N4/Chlorocobaloxime Nanocomposites as Multifunctional Electrocatalysts for Water Splitting and Energy Storage

“…Also, the new peak that appears at around 2150 cm −1 is observed only in the composite, which is due to N� C�N that indicates the accumulation of electrons on g-C 3 N 4 layers, pointing to a Coulombic mechanism of intercalation. 51 3.2. UV-DRS Spectroscopy.…”

“…Also, the new peak that appears at around 2150 cm –1 is observed only in the composite, which is due to N=C=N that indicates the accumulation of electrons on g-C 3 N 4 layers, pointing to a Coulombic mechanism of intercalation. 51 …”

Role of dopants and defects on the photocatalytic performance of g-C3N4 under visible light and sub-band gap excitation

“…The distance between two s-heptazine units characterises the (100) peak with a d-spacing of 0.675 nm [2]. Weakening or disappearance of this peak after doping indicates distortion of the in-plane ordering of the s-heptazine motifs [9,18]. At 2θ = 37.8 • and 58.9 • , two additional peaks that correspond to MgO emerge [19].…”

“…The available reports show that dopants such as B, N, O, S, and I preferentially bind to the C/N lattice sites, thereby disturbing the lattice. However, K, Na, Fe, and Cu go into the in-plane nitrogen gaps of g-C 3 N 4 , preserving the structural regularity [5,8,9]. Wang et al reveal that the intercalated atoms' position profoundly affects the PC performance of Na/K doped g-C 3 N 4 .…”