Gamma rays is widely used in modern science and technology, but it may cause health damage to practitioners. In the present study, natural composites based on leather and high-Z elements (atomic number ≥ 56) were fabricated and used as gamma rays shielding materials. These shielding materials were prepared by coating rare earth nanoparticles (Er₂O₃ or La₂O₃) onto the surface of natural leather, which was first impregnated with Bi³⁺ and Ba²⁺. Results show that the attenuation efficiency of the prepared Er_1.31Bi_5.46-NL (1.31 and 5.46 mmol cm⁻³ loaded elements) with thickness of 3.2 mm was 61.57% for incident rays at 121.78 keV (¹⁵²Eu) and reached 96.4% in the incident of 59.5 keV (²⁴¹Am), which is comparable to that of 0.25-mm lead plate (54.54 mmol cm⁻³). In addition, these natural-leather-based shielding materials exhibited low density (approximately 1/10 of Pb), high strength and wearable behaviors. Graphical abstract

Effective protection against X-ray is the premise of utilizing the X-ray, thus it is critical to develop novel X-ray shielding materials with both low density and high X-ray attenuation efficiency. As the even distribution of high-Z element components is of great significance for increasing the attenuation efficiency of X-ray shielding materials, in this study, the microfiber membrane (MFM), a type of synthetic leather featuring hierarchical structure was chosen to provide large surface area for the dispersion of rare earth (RE) element. Meanwhile, plant polyphenol was utilized to achieve the stable loading and uniform dispersion of the Ce or Er into MFM. Benefiting from the assistance of polyphenol and hierarchical structure of MFM, the even dispersion of RE element was successfully realized. The resultant shielding materials displayed approximately 10% superior X-ray attenuation efficiency compared to that without polyphenol, and an averagely 9% increment in X-ray attenuation efficiency than that without hierarchical structure. Moreover, the obtained composite with a thickness of 2.8 mm displayed superior X-ray shielding performance compared to 0.25 mm lead sheet in 16–83 keV and retained an ultralow density of 1.4 g cm^–3. Our research results would shed new light on the manufacture of high-performance X-ray shielding materials with excellent X-ray shielding performance. Graphical Abstract