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

Abstract

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.