Single-atom catalytic growth of crystals using graphene as a case study

Abstract

Anchored Single-atom catalysts have emerged as a cutting-edge research field holding tremendous appeal for applications in the fields of chemicals, energy and the environment. However, single-atom-catalysts for crystal growth is a nascent field. Of the few studies available, all of them are based on state-of-the-art in situ microscopy investigations and computational studies, and they all look at the growth of monolayer graphene from a single-atom catalyst. Despite the limited number of studies, they do, collectively, represent a new sub-field of single-atom catalysis, namely single-atom catalytic growth of crystalline solids. In this review, we examine them on substrate-supported and as freestanding graphene fabrication, as well as rolled-up graphene, viz., single-walled carbon nanotubes (SWCNT), grown from a single atom. We also briefly discuss the catalytic etching of graphene and SWCNT’s and conclude by outlining the future directions we envision this nascent field to take.

Zinc Single Atom Confinement Effects on Catalysis in 1T-Phase Molybdenum Disulfide

“…These observations further confirm that rather than substituting into the lattice, the Zn SAs adsorb to the basal plane of 1T-MoS 2 . It is worth mentioning that the dynamic movement of SAs under electron beam conditions is well-known. − It would be intriguing to understand if the dynamics of SAs persist under catalytic conditions. However, a spectroscopic or microscopic technique needs to be developed that can confirm the dynamics of SAs while supplying the minimum amount of external energy required to trigger their movements.…”

Linear indium atom chains at graphene edges

“…Our findings experimentally extend the concept of metal decoration of graphene edges from isolated atoms to atomic chains along the edges. Thus, not only single atoms can be prepared on graphene edges (as in prior literature [26][27][28][29][30] ), but also metal-atom chains can decorate them. This may be of future interest in tuning electronic properties of GNRs by metal-atom chain decoration.…”

“…So far, several elements in the form of individual metal atoms (e.g. Fe, Cr, Cu, Sn, Ni, Al, Pt and Au) attached to graphene edges have been revealed via transmission electron microscopy (TEM) [26][27][28][29][30][31][32][33][34][35] . Via single-walled carbon nanotube (SWNTs) opening, also the creation and atomic-resolution characterization of sulfur (S)-terminated GNRs by TEM has been reported 3,16 .…”

Progress on the in situ imaging of growth dynamics of two-dimensional materials

“…Many studies have evidenced that single atoms will participate in the growth of graphene on metal substrates. 92 The catalysis involves the connection of single atoms to the edge of 2D materials. And then, the growth (i.e., atom attachment) is catalysed at the catalysis site.…”