Red Phosphorus‐Induced Transformation of Gold Mesh into Crystalline Gold Phosphide Mesh

Among transition metal phosphides, gold phosphide (Au ₂ P ₃ ) is particularly uncommon and lacks established synthesis methods for large‐scale or structurally controlled materials, thus hindering its functional applications. This study introduces a synthetic strategy involving annealing gold mesh in red phosphorus vapor within a sealed quartz tube reactor, enabling a direct structural transformation into crystalline Au ₂ P ₃ while preserving macroscopic geometry. Comprehensive characterization using X‐ray diffraction, scanning electron microscopy, energy‐dispersive X‐ray spectroscopy, and X‐ray photoelectron spectroscopy confirms successful formation, revealing covalent AuP bonding and a semiconducting nature validated by density functional theory simulations, which accurately predict lattice parameters and electronic properties. This method opens possibilities for practical applications of Au ₂ P ₃ .