Defective Hexagonal Boron Nitride Nanosheet on Ni(111) and Cu(111): Stability, Electronic Structures, and Potential Applications.

Defective hexagonal boron nitride nanosheets (h-BNNSs) supported by Ni(111) and Cu(111) surfaces have been systematically studied in this work by first-principles methods. The calculation results show that various defects play an important role in enhancing the stability of h-BNNS/metal heterostructure. Importantly, significant electron transfer through the interface between metal substrate and h-BNNS to the defect sites can make h-BNNS more catalytically active. Using the oxygen reduction reaction (ORR) as a probe, it is shown that the binding energies of O2*, OH*, OOH*, and O* on h-BNNS/Cu(111) with a boron vacancy (VB) are quite similar to those observed on the Pt(111) surface, suggesting inert h-BNNS materials with defects can be functionalized by metal surfaces to become catalytically active for the ORR process. On the other hand, the reaction mechanism of CO oxidation on Ni(111) and Cu(111) supported h-BNNS with VB is systematically investigated. The h-BN/Cu(111) catalyst with a VB precovered by a CO species exhibits catalytic capacity for CO oxidation with a lower energy barrier compared with that on h-BN/Cu(111) without any defect. While on Ni(111) supported h-BNNS with a N vacancy, the defect site turns to be dominated by O2 and the energy barrier is significantly increased, indicating its dependence on the type of defect. This work will provide information for designing h-BN-based catalysts in heterogeneous catalysis.