Synthesis and characterization of Ag-doped cerium oxide nanoparticles for electromagnetic radiation shielding.

In the current study, CeO2: Ag (0 and 11 mol) nanoparticles (NPs) were synthesized by solution combustion method using Aloevera extract as reducing agent. As-obtained NPs were characterized by standard techniques. Bragg's reflections confirm the formation of a single-phase cubic structure of CeO2:Ag NPs. Crystalline size is calculated using both the W-H plot and Scherrer's equation. Crystallite size found to decrease with increase in the dopant concentration. EDAX pattern confirmed the presence of Ce, O and Ag. Direct energy band calculated using Wood and Tauc's was found to be in the range of 2.9-2.2 eV for 0 and 11 mol, respectively. Fourier transformation infrared spectroscopy (FTIR) analysis confirmed the presence of the functional groups. Total shielding efficiency (SET) will give the best representation of EMI shielding properties. SET values calculated for a wide range of wavelengths are found to be as follows: near infrared (1.65 × 102 dB), mid infrared (9.78 × 101 dB) and far infrared (6.32 × 101 dB), followed by microwave region (MW) (6.46 × 101 dB), ultra-high frequency (UHF) (7.31 × 101 dB), very high frequency (VHF) (8.27 × 101 dB), high frequency (HF) (9.26 × 101 dB), medium frequency (MF) (1.02 × 102 dB), low frequency (LW) (1.12 × 102 dB), very low frequency (VLF) (1.22 × 102 dB), ultra-low frequency (ULF) (1.42 × 102 dB) and extremely low frequency (ELF) (1.52 × 102 dB). SET values of CeO2:Ag NPs are compared with other traditional materials and nanocomposites and found to be potential use in EMI shielding applications.