Environmental Stability Diversity in Elemental Phosphorus: The Case of Black, Violet, and Fibrous Red Phosphorus

The rapid progress of elemental phosphorus families raises a pressing question: which of the allotropes is the most environmentally stable? Clear experimental evidence remains lacking. To this end, the stability discrepancies and underlying degradation chemistry of black phosphorus (BP), violet phosphorus (VP), and fibrous red phosphorus (FP), -the three most extensively studied among phosphorus families are systematically investigated, by monitoring the spectroscopic and microscopic evolution combined with first-principles calculations. The ambient degradation behavior of three elemental phosphorus flakes follows pseudo-first-order reaction kinetics. The corresponding monoexponential fitting yields rate constants k_BP, k_VP, and k_FP of 0.11, 0.18, and 0.23 day^-1, respectively, quantitatively revealing that the environmental stability decreases in the order BP > VP > FP. Such stability discrepancy can also be qualitatively explained by the dissociative chemisorption energy of oxygen atoms based on first-principles calculations. This work sheds new light on stability discrepancies and underlying degradation chemistry, paving the way for effective stabilization techniques.