Sol Gel-Based Synthesis of the Phosphorus-Containing MAX Phase V<sub>2</sub>PC
Jordan Sinclair, Jan P. Siebert, Mikkel Juelsholt, Chen Shen, Hongbin Zhang, Christina S. Birkel
Abstract
More than 150 MAX phases are known to date. Their chemical diversity is the result of mixing-and-matching early-to-mid transition metals (M), main group elements (A), and carbon and/or nitrogen (X). The vast majority of the respective carbides and (carbo)nitrides contain group 13 and 14 as the A element, such as Al, Ga, and Si. V2PC is among the least studied members of this family of materials; as a matter of fact, it is only mentioned in two pieces of original literature. The solid-state synthesis is extremely vaguely described and working with elemental phosphorus poses additional synthetic challenges. Here, we confirm these experimental difficulties and present an alternative sol gel-based approach to prepare almost single-phase V2PC. The versatility of the sol gel chemistry is further demonstrated by variation of the gel-building agent moving beyond citric acid as the carbon source. DFT calculations support the experimentally obtained structural parameters and show V2PC is a metal.