Structural transformation of h-BN overlayers on Pt(111) in oxidative atmospheres

Abstract

Interaction of hexagonal boron nitride (h-BN) with gases is of great importance for its properties and applications. In the present work, the structural changes of h-BN overlayers on Pt(111) in oxidative atmospheres including O2 and NO2 have been investigated by using low energy electron microscopy, Auger electron spectroscopy, X-ray photoelectron spectroscopy (XPS), and near ambient pressure XPS. We find that h-BN islands can be intercalated by oxygen in 10-6 Torr O2 at 200 °C, while oxygen intercalation of full layer h-BN around 200 °C requires near ambient pressure O2 (0.1 Torr) or such a strong oxidant as NO2 (10-6 Torr). h-BN overlayers can be etched away in the gases at much high temperatures, e.g. 800 °C. Upon mild oxidation in O2 or NO2 at temperatures of 400-450 °C, h-BN is transformed to boron oxide (BOx) overlayers, which can be converted back to h-BN by heating in NH3 at 800 °C.

Role of Undercoordinated Sites for the Catalysis in Confined Spaces Formed by Two-Dimensional Material Overlayers

“…First, the most interesting finding is the O feature above 600 K. The binding energy of 532 eV suggests the formation of a B–O bond, which strongly indicates that small amounts of CO are dissociated between h -BN and Rh(111) at low temperatures with dissociated O remaining in the h -BN overlayer. A similar O 1s feature was also observed by Meng et al, where h -BN/Pt­(111) was exposed to a mild oxidation environment in O 2 or NO 2 . Second, the completion temperature of CO desorption is higher for the h -BN overlayer/Rh system (top, 605 K; hollow, 575 K) than for the uncovered Rh surface (top, 480 K; hollow, 400 K).…”

“…A similar O 1s feature was also observed by Meng et al, where h-BN/ Pt(111) was exposed to a mild oxidation environment in O 2 or NO 2 . 57 Second, the completion temperature of CO desorption is higher for the h-BN overlayer/Rh system (top, 605 K; hollow, 575 K) than for the uncovered Rh surface (top, 480 K; hollow, 400 K). For h-BN overlayer/Rh, we find a smaller desorption temperature difference between the TOP site and the FCC site (ΔT = 30 K for h-BN/Rh, and ΔT = 80 K for Rh).…”

Oxygen Functionalization of Hexagonal Boron Nitride on Ni(111)

“…The few available approaches to modify the properties of h‐BN mostly concern intercalation; however, also the oxidation is observed as a side reaction during such experiments . This situation is different from that regarding the intercalation of graphene, where already numerous intercalation studies can be found in the literature, ranging from alkali metals, hydrogen to noble gases as intercalating agents.…”

“…The few available approaches to modify the properties of h-BN mostlyc oncern intercalation; [9][10][11] however,a lso the oxidation is observed as as ide reactiond uring such experiments. [12] This situation is different from that regarding the intercalation of graphene, where already numerous intercalation studies can be found in the literature, [13][14][15][16][17][18][19][20] ranging from alkali metals, [21] hydrogen [22] to noble gases [23] as intercalating agents. When studying the intercalation of supported 2D materials with gases,w ithi ncreasing strength of the interaction of the 2D materialw ith its substrate intercalationb ecomes increasingly more difficult to achieve.…”

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

“…In general, h-BN reacts with oxygen and forms boron oxide under certain conditions. For the h-BN/Pt(111) system the full conversion into boron oxide requires oxygen at nearly ambient pressures (0.15 Torr) and temperatures above 450 °C . On the other hand, the gradual oxidation of h-BN on Ir(111) occurs upon dosing with atomic oxygen from a high-temperature source .…”