A permeated hydrogen monitoring method based on poly(2,5-dimethoxyaniline) hydrogenochromic films

The real-time detection of hydrogen permeation presents a critical challenge in maintaining structural integrity of energy infrastructure exposed to hydrogen environments. We demonstrate an innovative hydrogen-responsive sensing platform employing nickel-enhanced poly(2,5-dimethoxyaniline) (PDMA) films with tunable chromogenic responses, and that was systematically optimized through three key operational parameters: nickel surface modification, temperature modulation (25–45 °C), and hydrogenation current density (1–8 mA/cm2). Experimental results demonstrate that the nickel coating significantly enhances the hydrogen sensitivity of PDMA films. The brightness change value (ΔY) increased from 0 to 77.449 for the nickel-coated film, compared to 0–70.0764 for the uncoated counterpart, indicating a more pronounced yellow chromogenic response. Elevating permeation temperature or hydrogenation current density can expedite color change, which increased the hydrogen atoms adsorbed on the steel surface. In other words, a greater concentration gradient prompted more hydrogen atoms to enter the interior of the substrate, thereby increasing the hydrogen flux and accelerating the hydrogen diffusion rate. These insights provide a refined approach to hydrogen detection, and the advancement is crucial for safeguarding infrastructure, particularly pipelines, against the substantial risks of hydrogen-induced damage.