Microbial fuel cell cathode with dendrimer encapsulated Pt nanoparticles as catalyst

In this paper, we investigated the use of polyamidoamine (PAMAM) dendrimer-encapsulated platinum nanoparticles (Pt-DENs) as a promising type of cathode catalyst for air-cathode single chamber microbial fuel cells (SCMFCs). The Pt-DENs, prepared via template synthesis method, have uniform diameter distribution with size range of 3–5 nm. The Pt-DENs then loaded on to a carbon substrate. For comparison, we also electrodeposited Pt on carbon substrate. The calculation shows that the loading amount of Pt-DENs on carbon substrate is about 0.1 mg cm−2, which is three times lower than that of the electrodeposited Pt (0.3 mg cm−2). By measuring batch experiments, the results show that Pt-DENs in air-cathode SCMFCs have a power density of 630 ± 5 mW m−2 and a current density of 5200 ± 10 mA m−2 (based on the projected anodic surface area), which is significantly better than electrodeposited Pt cathodes (power density: 275 ± 5 mW m−2 and current density: 2050 ± 10 mA m−2). Additionally, Pt-DENs-based cathodes resulted in a higher power production with 129.1% as compared to cathode with electrodeposited Pt. This finding suggests that Pt-DENs in MFC cathodes is a better catalyst and has a lower loading amount than electrodeposited Pt, and may serve as a novel and alternative catalyst to previously used noble metals in MFC applications.

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► Dendrimer-encapsulated platinum nanocomposites (Pt-DENs) and electrodeposited Pt nanoparticles are prepared as cathodic catalyst of MFCs.
► Compared to electrodeposited Pt- based cathode, the Pt-DENs/carbon paper cathode shows better electrochemical performance and catalytic activity.
► Pt-DENs has improved the oxygen reduction reaction in cathodes and increased the power output to 630 mW m−2.