Superamphiphobic and photochromic coatings based on tungsten oxide can be utilized for repetitive writing under UV light in harsh environments

Photochromism, a reversible color change induced by light exposure, has applications in optical information storage and transmission, chemical sensors, and rewritable systems. However, current photochromic materials face challenges such as high cost, toxicity, slow coloration, low efficiency, and poor durability, hindering their real-world applications. In this study, we designed a tungsten oxide-based photochromic material using hydrothermal and fluorination techniques, resulting in superamphiphobicity, low adhesion, thermal and chemical resistance, as well as UV and abrasion resistance. The superamphiphobicity is attributed to the flower-like hierarchical structure. By controlling the morphology and introducing organic fluorosilane as an electron donor to facilitate rapid electron transfer and proton insertion, we significantly enhanced the photochromism of the modified surface. The modified photochromic material faded within 3 min of UV irradiation and 90 min of heating at 80 °C in air. This development exhibits environmentally friendly, low cost, fast color conversion, scalability for mass production, and adaptability to harsh environments, indicating significant potential for applications in fields such as information security storage and rewritable materials.