title: Oxidative Etching of Hexagonal Boron Nitride Toward Nanosheets with Defined Edges and Holes.
abstract: Lateral surface etching of two-dimensional (2D) nanosheets results in holey 2D nanosheets that have abundant edge atoms. Recent reports on holey graphene showed that holey 2D nanosheets can outperform their intact counterparts in many potential applications such as energy storage, catalysis, sensing, transistors, and molecular transport/separation. From both fundamental and application perspectives, it is desirable to obtain holey 2D nanosheets with defined hole morphology and hole edge structures. This remains a great challenge for graphene and is little explored for other 2D nanomaterials. Here, a facile, controllable, and scalable method is reported to carve geometrically defined pit/hole shapes and edges on hexagonal boron nitride (h-BN) basal plane surfaces via oxidative etching in air using silver nanoparticles as catalysts. The etched h-BN was further purified and exfoliated into nanosheets that inherited the hole/edge structural motifs and, under certain conditions, possess altered optical bandgap properties likely induced by the enriched zigzag edge atoms. This method opens up an exciting approach to further explore the physical and chemical properties of hole- and edge-enriched boron nitride and other 2D nanosheets, paving the way toward applications that can take advantage of their unique structures and performance characteristics.
authors.affiliation: National Institute of Aerospace, 100 Exploration Way, Hampton, VA, 23666, USA.|Department of Chemistry, Institute for Functional Nanomaterials, University of Puerto Rico, Rio Piedras Campus, San Juan, Puerto Rico, 00931, USA.
authors.forename: Yunlong
authors.initials: Y
authors.lastname: Liao
authors.affiliation: Department of Chemistry, Institute for Functional Nanomaterials, University of Puerto Rico, Rio Piedras Campus, San Juan, Puerto Rico, 00931, USA.
authors.forename: Kaixiong
authors.initials: K
authors.lastname: Tu
authors.affiliation: Department of Materials Science and Engineering, The University of Maryland, College Park, MD, 20742, USA.
authors.forename: Xiaogang
authors.initials: X
authors.lastname: Han
authors.affiliation: Department of Materials Science and Engineering, The University of Maryland, College Park, MD, 20742, USA.
authors.forename: Liangbing
authors.initials: L
authors.lastname: Hu
authors.affiliation: Advanced Materials and Processing Branch, NASA Langley Research Center, Hampton, VA, 23681-2199, USA.
authors.forename: John W
authors.initials: JW
authors.lastname: Connell
authors.affiliation: Department of Chemistry, Institute for Functional Nanomaterials, University of Puerto Rico, Rio Piedras Campus, San Juan, Puerto Rico, 00931, USA.
authors.forename: Zhongfang
authors.initials: Z
authors.lastname: Chen
authors.affiliation: National Institute of Aerospace, 100 Exploration Way, Hampton, VA, 23666, USA.|Department of Applied Science, The College of William and Mary, Williamsburg, VA, 23185, USA.
authors.forename: Yi
authors.initials: Y
authors.lastname: Lin