Metal Oxychlorides: From Novel 2-D Magnets to Novel Nitrogen Reduction Photocatalysts

Abstract

The development of novel, intrinsic two-dimensional magnets presents the opportunity to vastly improve the efficiency of spintronic devices and sensors, as well as to explore the existence of exotic quantum phases and novel quantum particles. This thesis explores the exfoliation of transition metal oxychlorides (crystallizing in the PbFCl and closely related structure types) with the goal of synthesizing new 2D magnets. Materials crystallizing in the layered PbFCl structure type have also been recently identified for their potential in the development of novel nitrogen-reduction photocatalysts, which would also allow for a more widespread and efficient means of ammonia production. In the present work, I explore the synthesis, lithium intercalation, and exfoliation into nanosheets of transition metal oxychlorides FeOCl, CrOCl, VOCl, and TiOCl, as well as the synthesis and characterization of potential nitrogen reduction photocatalysts BiOBr, PbBiO2Br, and PbFBr. The magnetic properties of each transition metal oxychloride, its lithium intercalate, and its mono- or bilayer nanosheets were measured to determine the evolution of magnetic character for each material from the three-dimensional to the two-dimensional system. The potential of each synthesized catalyst in the photoreduction of molecular nitrogen to ammonia was explored by collaborators in the Chirik lab. Experimental outcomes suggest that further studies on the exfoliation of transition metal oxychlorides to two-dimensional nanosheets could result in the discovery of novel 2-D magnets.