Highly Stretchable, Robust, and Floatable Broadband Light Absorber of Carbon Nanotubes–Ecoflex Composite on 3D Mogul-Pattern for Photothermal Conversion

Abstract

Addressing the need for efficient and durable photothermal materials, this study presents a novel composite material composed of carbon nanotubes (CNTs) embedded in an Ecoflex matrix with a 3D mogul pattern. This material enhances photothermal effects and is engineered for highly stretchable, durable, and floatable broadband light absorption. Combining CNT-based inherent light absorption and the 3D mogul pattern with micro-cavities effectively captures a broad spectrum of light from ultraviolet (UV) to near-infrared (NIR) of (250–1500) nm, achieving an average absorption of 98%. Uniform CNT distribution in Ecoflex elastomer on the 3D mogul pattern reduces stress concentration, ensuring a robust, elastic platform. This platform withstands stretching, deformation, intense pulsed light, and salt-aging without compromising optical properties across the UV–vis–NIR range. Under a 1-sun solar simulator, the structure's photothermal effect is evident, reaching 74.6 °C. The floatable nature of the composite makes it ideal for solar desalination, achieving a 0.52 kg m⁻² h⁻¹ evaporation rate under 1-sun. Furthermore, the curved CNT–Ecoflex mogul structure embedded in ice melts within 30 min under 2 sun exposure, regaining its flat, stable form. This multifunctional material offers high mechanical resilience, excellent light absorption, and versatile deployment for renewable energy harvesting and environmental sustainability.