Selective adsorption of atomic hydrogen on a h-BN thin film

Abstract

The adsorption of atomic hydrogen on hexagonal boron nitride (h-BN) is studied using two element-specific spectroscopies, i.e., near-edge x-ray absorption fine structure (NEXAFS) spectroscopy and x-ray photoelectron spectroscopy (XPS). B K-edge NEXAFS spectra show a clear change in the energy region of the π* band before and after reaction with atomic deuterium. On the other hand, N K-edge NEXAFS spectra show only a little change. B 1s XPS spectra show a distinct component at the low binding energy side of a main component, while N 1s XPS spectra show peak broadening at the high binding energy side. These experimental results are analyzed by the discrete variational Xα method with a core-hole effect and are explained by a model in which hydrogen atoms are preferentially adsorbed on the B sites of h-BN. Based on the experimental and theoretical results, we propose a site-selective property of BN material on adsorption of atomic hydrogen.

Oxygen Functionalization of Hexagonal Boron Nitride on Ni(111)

“…The spectra of pristine h-BN on Ni(111)a gree very well with the literature [8,[33][34][35][36] .A tt he BK -edge, the dominating peak a 0 lies at 191.9 eV,a nd the s*t ransitions of h-BN are observed as two peaks at 197.3 and 198.3 eV.A tt he NK -edge, h-BN shows one main feature at 402 eV,whichisassociated with a p*transition, and the s*t ransitions are found from 405 to 417 eV.I na ddition, so-called interlayer states were assigned to the interaction (hybridization)o fh -BN with the Ni(111)s ubstrate. [34][35][36] We have marked their photon energy ranges with red doublea rrows in Figure 4a,b. These states have p*-character and lie parallel to the h-BN sheet.…”

“…[34][35][36] We have marked their photon energy ranges with red doublea rrows in Figure 4a,b. At the boron K-edge, they manifest themselves as abroad feature from approximately 193 to 195 eV.Atthe nitrogen K-edge, they are typically found between about 397 and 399 eV, [34][35][36] with am aximum at around 398 eV.T hese interlayerstates and the a 0 peak have been interpreted as indicators of the interaction strength of h-BN with the substrate:a large a 0 peak andw eak or vanishing interlayer states indicate quasi-free-standing h-BN. At the boron K-edge, they manifest themselves as abroad feature from approximately 193 to 195 eV.Atthe nitrogen K-edge, they are typically found between about 397 and 399 eV, [34][35][36] with am aximum at around 398 eV.T hese interlayerstates and the a 0 peak have been interpreted as indicators of the interaction strength of h-BN with the substrate:a large a 0 peak andw eak or vanishing interlayer states indicate quasi-free-standing h-BN.…”

Boron Nitride Nanosheets for Metal Protection

“…[25] The N 1s spectrum of the BN nanosheet prior to heating is also dominated by the B-N bonds with the binding energy of 398.0 eV, along with a shoulder at 396.8 eV which is possibly associated with nitrogen atoms bonded to the hydrogenated boron atoms (Figure 4b). [30] After heating for 100 h, the shoulders at the lower binding energies in both the B 1s and N 1s spectra disappears. The N 1s spectrum reduces to a single peak corresponding to B-N; the B 1s spectrum, on the other hand, contains a new shoulder at 191.7 eV, which is attributed to the formation of B-O bonds.…”

“…The black regions observed on the BN+Cu foil under optical microscopy increased only slightly in size, from about 30% from 2 h heating to about 37% as the heating time increased to 100 h. As the EDX technique is not sufficiently surface sensitive to probe the BN nanosheet, chemical changes to the BN nanosheet before and after the 100 h heating treatment were investigated using X-ray photoelectron spectroscopy (XPS). The B 1s spectrum of the BN nanosheet on the copper foil prior to heating appears to comprise two components ( Figure 4a): a dominant peak centered at 190.4 eV which is characteristic of B-N bonds [29] and a shoulder at 189.0 eV assigned to hydrogenated boron atoms (B-H) [30] which are intermediate products during the CVD growth process. [25] The N 1s spectrum of the BN nanosheet prior to heating is also dominated by the B-N bonds with the binding energy of 398.0 eV, along with a shoulder at 396.8 eV which is possibly associated with nitrogen atoms bonded to the hydrogenated boron atoms (Figure 4b).…”

Fringe structures and tunable bandgap width of 2D boron nitride nanosheets

“…For example for BN nanotubes (BNNT), 50% tube surface coverage with chemisorbed hydrogen atoms would cause the BN band gap (which was computed to be 4.29 eV in pristine BNNT) decreased to 2.01 eV [11]. For BNNSs case the adsorption behavior of a single H atom either on the top site of a B or on the top site of an N atom, or two H atoms adsorbed on adjacent B and N sites are also investigated [12]. Using first-principles computations [13] and hybrid density functional theory calculations with van der Waals correction [14], Chen and Zhang show that polar boron nitride (BN) nanoribbons can be favorably aligned via substantial hydrogen bonding at the interfaces, which induces significant interface polarizations and sharply reduces the band gap of insulating BNNSs.…”