Environmental-driven degradation of violet phosphorus and its passivation by graphene

Violet phosphorus (VP), as a promising layered semiconductor material, exhibits significant potential in electronic and optoelectronic applications. However, the susceptibility of VP to environmental conditions limits its practical application. It is of great strategic significance to reveal the degradation mechanism of VP and explore effective passivation for long-term stable use. This paper investigated the degradation of VP by varying environmental conditions with controllable oxygen (O₂) and water (H₂O). Under conditions of high humidity (25 ℃, 70 %RH), room temperature (25 °C, 45 %RH), and high temperature (60°C, 45 %RH), VP began to degrade after 1 h, 2 h, and 4 h, respectively. The results indicated that in environments with high oxygen and moisture content, the oxidation rate of VP significantly increased. The degradation of VP was owing to the formation of VP oxides (P₂O₅), and further hydrolyzation into orthophosphoric acid (H₃PO₄) under high humidity. The graphene was employed for passivating VP, which significantly enhanced its stability by preventing oxidation from 2 h up to 192 h. The theory calculations demonstrated that O₂ and H₂O accelerated the degradation of VP, according well with the experiment results. This work not only provides fundamental insights into the degradation of VP, but also develops a novel approach to prevent the degradation for its further advanced applications.