Barium Doped Ceria Based Material and its Electrochemical and Photocatalytic Properties at Low Temperatures

Abstract

Energy demand and environmental degradation became the cause of alarming situation for the entire world. Therefore, switching from conventional to non-conventional or renewable energy sources is urgently required. In the era of renewable energy resources, solid oxide fuel cells (SOFCs) are more fascinating owing to their multiple properties and functionalities. The electrolytes are considered as the key component in fabrication of SOFCs. To overcome SOFC-related problems such as high operating temperatures, it is difficult to develop appropriate materials for the electrolyte. Herein, we developed novel nanocomposites as barium doped ceria (BDC) electrolyte material coated with alkali carbonates via cost effective co-precipitation and sol-gel routes. X-ray diffraction (XRD), scanning electron microscopy, and other techniques were used to examine the structural, morphological, elemental, and optical characteristics of synthesized electrolyte materials (SEM), energy dispersive spectroscopy (EDS), and photoluminescence spectroscopy (PL). The DC conductivity and cell performance measurements were recorded using four-probe technique and fuel cell testing unit. Results depicted that the average crystallite size lies in the range of 23-29 nm. The electrolyte material prepared by coprecipitation has dense structure; particles are well placed with each other and have shown maximum ionic conductivity of 0.2 Scm -1 at 550 o C. The highest power density of 383 mWcm -2 with open circuit voltage of 0.89 V is obtained at 550 o C with BDC electrolyte prepared by co-precipitation method. The result showed that prepared electrolyte materials can be considered as the best alternative for SOFC applications. Photocatalytic degradation of Congo Red dye has been checked using BDC material prepared by co-precipitation method showing 77.89 % degradation efficiency, while BDC material prepared via sol gel method showed degradation efficiency of 68.42%. Degradation of Rocephin antibiotic has also been calculated as 54.27% by BDC from co-precipitation method, whereas BDC prepared by sol gel method depicted the percent efficiency of 48.24% respectively. Thus the comparative efficiency of prepared BDC materials provides a better choice because for fuel cell application, it is used as an electrolyte and photocatalyst for degradation of dyes and antibiotics in near future.