Interfacial active-sites p-n heterojunction SFT-WO3 for enhanced fuel cell performance at 400-500?C

The enhanced ionic conductivity of electrolytes in fuel cells could be optimized by inhibiting the e-conduction, constructing heterostructure, built-in electric field (BIEF), and creating a more active site within the lattice. High ionic conductivity and suppression of e-conductivity are of paramount signifi-cance in the field of a fuel cell. One possible approach is synthesizing the type-II heterojunction to achieve high ionic conductivity and enhanced fuel cell performance. In this perspective, we have syn-thesized p-n heterojunction SFT (SrFe0.3Ti0.8O3)-WO3 via compositing the individual SFT (p-type) and WO3 (n-type) semiconductors. The obtained SFT-WO3 exhibit impressive fuel cell performance of 875 mW/cm2, high ionic conductivity of 0.2 S/cm, and better OCV 1.04 Vat a low operating temperature of 520 degrees C. The excellent fuel cell performance and high ionic conductivity can be interpreted as the synergistic effect between SFT-WO3 heterojunction and BIEF. Various characterizations (XRD, SEM, HR-TEM, UV-visible, UPS, and XPS) confirmed heterojunction formation between SFT and WO3. Further-more, the energy band structure and valence band deviation of the SFT-WO3 junction were approved. Also, the theoretical calculation (DFT calculation) has been performed to support the experimental results. Our finding reveals that the synthesized heterostructure SFT-WO3 is a competent and promising electrolyte indicating the insight of developing low-temperature-based electrolytes for fuel cell technology.(c) 2022 Elsevier Ltd. All rights reserved.

Automated summary

The enhanced ionic conductivity of electrolytes in fuel cells can be optimized through methods such as constructing heterostructures and creating built-in electric fields, which are of paramount significance for improving fuel cell performance. In this study, a p-n heterojunction system SFT-WO3 was synthesized and demonstrated to exhibit high ionic conductivity and impressive fuel cell performance, revealing the synergistic effect between the heterojunction and built-in electric field.