Diamond Nanoparticles in Heterogeneous Catalysis

Abstract

The use of diamond nanoparticles in catalysis has attracted considerable interest during the last three decades since these materials have been made commercially available. Diamond nanoparticles have been employed as supports of a small metal or metal oxide nanoparticles, as scaffolds for covalent grafting of organic molecules or metal complexes, and as carbocatalysts by generating a few layers of sp 2 carbons or other heteroatoms on the external surface. This review describes the main structural and chemical properties of diamond nanoparticles that have led to the development of catalysts with superior activity with respect to the use of analogous catalysts based on other carbon allotropes, carbon materials or even some benchmark metal oxides. These diamond-based materials have found superior applications as catalysts, photocatalysts, and more recently as carbocatalysts.

New Insights into the Reactivity of Detonation Nanodiamonds during the First Stages of Graphitization

“…In summary, our study provides a fine characterization of the early stages of graphitization of DND. Our results emphasize that within the 800-1100 • C range and for this source of nanodiamonds, it is possible to finely control the amount and the crystallinity of sp 2 -hybridized carbon at the periphery of DND mainly from the first outer-shell, while the coexistence of C-H functions cannot be avoided. It may be of interest to investigate these early stages of graphitization on other DND sources to better define how these results are particle dependent.…”

“…The sp 3 carbon one at 285.4 eV was taken as reference, reflecting intrinsic diamond. The component related to sp 2 carbon is downshifted at −1 eV [48]. Its asymmetry, linked to its conductor character, was taken into account in the fit (Figure 4b).…”

“…Indeed, ND gather the outstanding physical and chemical properties of the bulk diamond and new assets conferred by the nanoscale. Among the different ND sources, nanodiamonds produced by detonation (DND) are actively investigated, mainly for bioapplications, catalysis, novel lubricants, and composites [1][2][3][4]. For instance, DND are widely used as vectors for delivery of drugs or genetic material [5,6] for their <10 nm diameter provides a high specific surface area (up to 400 m 2 /g) and allows to expect renal clearance [7].…”

Sustainable Catalytic Processes Driven by Graphene-Based Materials

“…Introducing boron into the N-doped graphene results in more reactive carbons and improves the performance of N-doped graphene, and the catalysis is determined by the relative distance/position of N and B atoms [71,72]. More recently, nanodiamonds (NDs) have been graphitized at high temperatures into sp 2 /sp 3 hybrids with graphitic shells and a diamond core [73,74]. The reactivity of the annealed NDs in AOPs is dependent on the relative proportion of sp 2 and sp 3 carbons as well as the surface chemistry (dopants and functionalities) of the outermost graphene sphere [75][76][77][78].…”

Photocatalytic and Optoelectronic Properties of Polycrystalline Diamond

“…Therefore, diamond can be used to degrade some organic pollutants, [20,21] which have been studied by using NCD photocatalysts. [22,23] However, the photocatalytic effect of diamond film has not been further explored. This paper aims to study the degradation rate of rhodamine B (RhB) using different diamond samples and to discover whether diamond is a good photocatalyst.…”