Oxygen Intercalation and Oxidation of Atomically Thin h-BN Grown on a Curved Ni Crystal

Abstract

We study the effect of thermal oxygen exposure on a monolayer of h-BN grown on vicinal Ni surfaces by scanning tunneling microscopy, X-ray absorption, and photoemission spectroscopies. Using a curved Ni crystal, we carry out a systematic exploration of the h-BN monolayer interfacing a full variety of vicinal orientations around the (111) high-symmetry direction. We demonstrate the occurrence of two processes upon oxygen exposure: oxygen intercalation underneath the h-BN layer, which leads to decoupling of the h-BN from the substrate, and oxidation of h-BN itself, which proceeds via substitution of nitrogen atoms. Oxygen intercalation appears to be substrate orientation dependent, while oxidation of h-BN is rather uniform over the different vicinal planes. These findings will be of importance for future applications of BN-based devices and materials under ambient conditions.

Highly Ordered and Polycrystalline Graphene on Co(0001) Intercalated by Oxygen

“…Upon oxygen intercalation, the strain is released, which points to the formation of cracks. − Dangling bonds at the boundaries can be readily passivated with atomic oxygen, which is produced during dissociative adsorption of O 2 molecules on the Co surface . Recently, a similar process of oxygen dissociation was observed upon thermal oxygen exposure of h-BN on Co and Ni surfaces. , These oxygen atoms can not only terminate graphene boundaries but also etch them, which was detected by XPS after prolonged exposures.…”

“…39 Recently, a similar process of oxygen dissociation was observed upon thermal oxygen exposure of h-BN on Co and Ni surfaces. 49,50 These oxygen atoms can not only terminate graphene boundaries but also etch them, which was detected by XPS after prolonged exposures. Now we turn to the oriented graphene/Co(0001) system.…”

Constructing Interfacial Boron‐Nitrogen Moieties in Turbostratic Carbon for Electrochemical Hydrogen Peroxide Production

“…This can be further confirmed by the high‐resolution XPS C 1s spectra (Figure 2d), revealing the apparent disappearance of C−B bonds at 283.4±0.3 eV in CNB‐ZIL 9 and 10. In N1s spectra of CNB‐ZIL catalysts (Figure 2c), five characteristic nitrogen peaks can be detected, assigned to i) N−B bond (N1, 397.5±0.3 eV), ii) pyridinic N (N2, 398.5±0.3 eV), iii) pyrrolic N (N3, 399.4±0.3 eV), iv) graphitic (N4, 400.4±0.3 eV) and v) inhomogeneous oxygen intercalation in the h ‐BN layers (N5, 396.7±0.3 eV) [23, 48] . The significantly increased ratio of NC species (N2‐3, Table S3, Supporting Information) in CNB‐ZIL 9 and 10 clearly evidences the preferable formation of N−C bonds under high annealing temperatures, where pyridinic N becomes dominant.…”

“…These are in the following substituted in-plane oxygen, as also previously reported. [48,50] Further insights were given by the N K-edge spectra of CNB-ZIL catalysts (Figure 3b), revealing a blue shift of π* transition feature at 399.0 eV for CNB-ZIL 9 and 10. Notably, the NEXFAS characterization is a sensitive probe of local bonding, thus a drastic change in the spectrum shape indicates a significant variation in the local coordination environment.…”

Constructing Interfacial Boron‐Nitrogen Moieties in Turbostratic Carbon for Electrochemical Hydrogen Peroxide Production

“…These are in the following substituted by in-plane oxygen, as also previously reported. [48,50] Further insights were given by the N K-edge spectra of CNB-ZIL catalysts (Figure 3b), revealing a blue shift of π* transition feature at 399.0 eV for CNB-ZIL 9 and 10. Notably, the NEXFAS characterization is a sensitive probe of local bonding, thus a drastic change in the spectrum shape indicates a significant variation in the local coordination environment.…”