Absolute energy levels in nanodiamonds of different origins and surface chemistries

Abstract

Nanodiamonds (NDs) are versatile, broadly available nanomaterials with a set of features highly attractive for applications from biology over energy harvesting to quantum technologies. Via synthesis and surface chemistry, NDs...

Oxidized Detonation Nanodiamonds Act as an Efficient Metal‐Free Photocatalyst to Produce Hydrogen Under Solar Irradiation

“…Therefore, oxidized and hydrogenated DND and MND behave very similar surface chemistries and mainly differ by their core quality. To be noticed, Miliaieva et al [ 28 ] also reconstructed the energy diagram of Ox‐MND and H‐MND and evidenced very similar band positioning between Ox‐DND and Ox‐MND, with a weak shift of 0.1 eV. Though, we performed photocatalysis experiments with both MND surface chemistries, in the same experimental conditions than with DND.…”

“…Very recently, a study from Rezek team confirmed experimentally that this shift is preserved at the nanoscale, even for DND. [ 28 ] A difference of 1.3 eV in the conduction and valence band positions is measured between both surface chemistries ( Scheme ). Furthermore, in the same study, authors confirm by optical measurements that the bandgap remains similar for Ox‐DND and H‐DND.…”

“…The different reactivity of Ox‐DND and H‐DND toward H 2 production may thus result from this modification of the DND band diagram after hydrogenation. For sake of clarity, we build the band diagrams of Scheme 1, adapted from Rezek study [ 28 ] for the DND and from Jimenez–Calvo study [ 29 ] for TiO 2 . This representation highlights the lower energy position of the Ox‐DND valence band, which may favor the water oxidation, source of H + , compared to H‐DND.…”

“…Band diagrams of H‐DND, Ox‐DND, and P25 TiO 2 obtained by experimental measurements, adapted from Miliaieva et al [ 28 ] and Jimenez‐Calvo et al [ 29 ] …”

Utilizing Constant Energy Difference between sp-Peak and C 1s Core Level in Photoelectron Spectra for Unambiguous Identification and Quantification of Diamond Phase in Nanodiamonds

“…They may also find use in energy storage as electrode materials in batteries and supercapacitors [3]. Their tunable electronic bandgaps and band edge positions relative to vacuum through modification of size, defects, non-diamond carbon phases, and surface chemistry [4] could enable applications 2 of 14 in optoelectronics such as light-emitting diodes, photovoltaics, and electron emitters [5]. Biomedical applications [6] are envisioned as well, taking advantage of biocompatibility and the broad options to functionalize nanodiamond surfaces for drug delivery or imaging.…”