Reliable detection of high-concentration hydrogen (H₂) leakage in sharp-vibration environments is highly desired such as in the application of space rockets. As hydrogen has to be detected simultaneously in a wide concentration range and at high concentrations (e.g., 100 v/v%) with outstanding linearity in response/concentration, lightweight features, and excellent tolerance against saturation and vibration, it remains challenging. Here, a flexible and high-concentration H₂ sensing has been developed through “dipping–drying” a three-dimensional (3D) porous polyurethane (PU) foam integrated with graphene oxide (GO-PU). Multilayered honeycomb-structured graphene oxide appears to be tightly adhered to faveolate PU. Benefiting from the numerous adsorption sites of the “dual honeycomb” structure and abundant surface functional groups of GO, the GO-PU foam exhibits distinguished response and linearity toward 2–100 v/v% H₂ and shows excellent lightweight, tailorability, and flexibility. Remarkably, the foam possesses outstanding sensing stability against 0–180° bending and low 0–20% straining, along with outstanding H₂ sensing performance even after being pressed by a weight of 200 g, immersed in water, and frozen in a refrigerator at −10.8 °C. Practically, the GO-PU foam has potential for high-concentration H₂ leakage detection, and our synthetic strategy may provide a way to avoid adsorbing saturation in other flexible gas sensing.

中文翻译：

---

与氧化石墨烯集成的轻质多孔聚氨酯泡沫用于灵活和高浓度的氢传感

非常需要在剧烈振动环境中可靠检测高浓度氢 (H ₂ ) 泄漏，例如在太空火箭的应用中。由于必须同时检测宽浓度范围和高浓度（例如 100 v/v%）下的氢气，同时具有出色的响应/浓度线性度、轻量化特性以及出色的饱和度和振动耐受性，因此它仍然具有挑战性。在这里，灵活且高浓度的 H ₂传感是通过“浸渍-干燥”与氧化石墨烯 (GO-PU) 集成的三维 (3D) 多孔聚氨酯 (PU) 泡沫开发的。多层蜂窝状结构的氧化石墨烯似乎紧紧地粘附在蜂窝状 PU 上。_{得益于“双蜂窝”结构的众多吸附位点和 GO 丰富的表面官能团，GO-PU 泡沫对 2–100 v/v% H 2}表现出卓越的响应和线性，并显示出出色的轻量化、可裁剪性和柔韧性. 值得注意的是，泡沫具有出色的传感稳定性，可抵抗 0–180° 弯曲和低 0–20% 应变，以及出色的 H ₂即使在被 200 g 重物压紧、浸入水中并在 -10.8 °C 的冰箱中冷冻后的传感性能。实际上，GO-PU 泡沫具有高浓度 H ₂泄漏检测的潜力，我们的合成策略可能提供一种避免其他柔性气体传感中吸附饱和的方法。