Facile fabrication of Au@polyaniline core-shell nanocomposite as efficient anodic catalyst for microbial fuel cells

Highlights: • Au@PANI core-shell composites were synthesized with an aid of ionic liquid. • The composites modification enhanced the electrocatalytic activity of the electrode. • The composites greatly improved the EET efficiency and the performance of MFCs. -- Abstract: Electrode modification with different catalytic nanoparticles or nanocomposites was promising for improving the performance of microbial fuel cells (MFCs). However, direct modification of electrode with metal nanoparticles encountered the drawback of low biocompability although these nanoparticles showed intriguing catalytic properties. In this work, conductive polymer encapsulation of metal nanoparticles was developed to improve the biocompability and then applied for anode modification in MFCs. The Au@polyaniline (Au@PANI) core-shell nanocomposite was simply synthesized with an aid of ionic liquid. Morphological, crystalline and structural properties were studied in details with SEM, TEM, XRD and FTIR analyses and an intact PANI shell covered on the sphere of Au nanoparticle was observed. Upon modification of this core-shell nanocomposite on carbon cloth electrode, significant improvement on bioelectrochemical activity was observed when compared with bare carbon cloth or carbon cloth modified with naked Au nanoparticles. As a result, the performance of MFCs was enhanced from 332 mW/m² to 804 ± 73 mW/m² by Au@PANI modification. These results demonstrated that encapsulation of metal nanoparticle with biocompatible and conductive polymer is promising for bioelectrochemical applications.