Enhanced wide energy regions gamma ray shielding property for Bi₂O₃-Gd₂O(CO₃)₂∙H₂O/EP composites with strong electron cloud overlap

With the complexity of the radiation environment and the increased demand for radiation protection, there is an urgent need for high-performance and wide-energy range gamma ray shielding materials. Bi₂O₃ has excellent gamma ray shielding properties, while Bi exhibits weak shielding performance of low-energy gamma rays in the range of 36.4–90.5 keV. In this work, a two-step hydrothermal strategy was proposed for Bi₂O₃-Gd₂O(CO₃)₂∙H₂O heterostructure (h-BG) to achieve effective shielding of the materials of low-energy gamma radiation. Bi₂O₃-Gd₂O(CO₃)₂∙H₂O/EP-30 composite has excellent shielding performance against low, medium, and high energy gamma radiation. In addition, the shielding performance of the Bi₂O₃-Gd₂O(CO₃)₂∙H₂O/EP-30 composites proved to be superior to some materials in the literature of 59.5 keV. Furthermore, simulations with the Phy-X/PSD program demonstrate that Gd₂O(CO₃)₂∙H₂O combined with Bi₂O₃ is an adequate method for achieving gamma radiation shielding in a wide energy region. The differential charge density calculations suggest that the formation of a heterogeneous interface between Bi₂O₃ and Gd₂O(CO₃)₂∙H₂O leads to an overlap of the interfacial electron cloud, which increases the probability of collision between the rays and the electrons. This is an essential reason for the enhanced gamma shielding property. This work could serve as a new strategy for the design of gamma radiation shielding materials.