Hydrothermal synthesis of Bi-Ce hydroxide/oxide nanomaterials: Multifunctional platforms for radiation shielding and environmental applications

The fabrication of Bi2Ce2O7 represents a significant advancement toward sustainable radiation shielding materials. In this work, a novel Bi2Ce2O7 semiconductor was synthesized from Bi2Ce2OH14, exhibiting an insulator-to-semiconductor transition and enabling multifunctional applications in radiation shielding, photocatalysis, and phytotoxicity mitigation. Comprehensive physicochemical and electrochemical characterizations were performed. XRD analysis revealed crystallite sizes of 13.36 nm for Bi2Ce2OH14 and 11.96 nm for Bi2Ce2O7 nanoparticles (NPs), while FTIR spectra confirmed Bi2Ce2O7 formation through characteristic metal-oxygen vibrations after annealing at 700 degrees C for 2 h. The Bi2Ce2O7 NPs showed an average particle size of similar to 39 nm and a high surface area of 81.765 m(2) g(-)(1), indicating finer morphology compared to the precursor hydroxide. Notably, Bi2Ce2O7 exhibited higher absorption efficiency for gamma rays than X-rays and demonstrated superior shielding against X-rays, gamma rays, and neutrons, achieving a low half-value layer (HVL) of 0.210 cm relative to commercial materials. Photocatalytic degradation efficiencies of 82.20% and 97.59 % were obtained for Bi2Ce2OH14 and Bi2Ce2O7, respectively, toward methylene blue. Weber-Morris intraparticle diffusion analysis revealed a multistep degradation mechanism. Enhanced photocatalytic activity was attributed to the anionic surface of Bi2Ce2O7, which promotes charge separation and reactive radical generation. This study presents Bi2Ce2O7 as a non-toxic, lead-free candidate for radiation shielding, environmental, and protective applications, marking the first report on the radiation attenuation performance of Bi2Ce2OH14 and Bi2Ce2O7 NPs.