180
A. Arkatkar et al.
of nanoparticles to be applicable in MFC. These metals are chosen due to the ability
of these metal oxides to accept electrons.
The metal oxide nanomaterials are generally mixed with polymer-like polytetrafluoroethylene (PTFE), (Rajesh et al. 2018) NAFION (mostly in case of aircathode) (Yan et al. 2013), etc. to provide a holding matrix for nanoparticles and
facilitating the growth of microbe. The coating of the composite on anode is done by
various methods like chemical vapor deposition, dip coating, simple brush coating,
doping, etc. out of which the latest method is electrodeposition where an external
voltage is applied to the solution which affects the polarity of the desired electrode
and leads to the deposition of oxide on the electrode.
The synthesis of nanoparticles is done chemically under high-temperature conditions. Few scientists are also exploring the green synthesis pathway of nanoparticles
where the microorganism, S. oneidensis MR-1 is used as reducing bacteria which can
synthesis the nanoparticles of palladium Pd by reducing Pd
2+ to Pd
0 on its cell walls
and in its periplasmic spaces (Quan et al. 2018; Wu et al. 2018). The plant extract of
A.blitum (Sekar et al. 2019) and A. Indica (Muthukumar et al. 2019) are also been
used as reducing agents of the synthesis of nanoparticles. As depicted in Table 1 all
the anode materials from graphite to carbon felt support the coating of nanoparticles.
The table also summarizes that use of nanoparticles is not subjected to any specific
design of MFC; it is used in both dual-chambered as well as single-chambered MFC
design.
The primitive goal of power enhancement is achieved with the coating of nanoparticles but the second parameter of wastewater treatment is also not a neglected aspect.
The researchers have achieved treatment of pharmaceutical, (Xu et al. 2018) dairy
(Sekar et al. 2019) as well as domestic wastewater (Mohamed et al. 2018a, b) using
these nanoparticles coated bioanodes. Thus, this approach is promising for both
fronts.
6 Future Prospects
Most of the power enhancement has been achieved and studied in laboratory scale
reactors. The research in this field has yet to be applied in field. In one such study
of benthic microbial fuel cell (BMFC) coating of cerium (Ce) nanoparticles was
applied which resulted in the enhancement of power density (Pushkar et al. 2018).
The need to apply the nanoparticles directly in field condition may face challenges
like loss of nanoparticles in the environment, durability and stability of coating, and
biocompatibility of these particles. The synthesis of nanoparticles through green
pathway is also under consideration. The potential of nanoparticles for the MFC
reactors can fix the minimum use of materials, good growth of biofilm, and better
surface area for electron reception.
A. Arkatkar et al.
of nanoparticles to be applicable in MFC. These metals are chosen due to the ability
of these metal oxides to accept electrons.
The metal oxide nanomaterials are generally mixed with polymer-like polytetrafluoroethylene (PTFE), (Rajesh et al. 2018) NAFION (mostly in case of aircathode) (Yan et al. 2013), etc. to provide a holding matrix for nanoparticles and
facilitating the growth of microbe. The coating of the composite on anode is done by
various methods like chemical vapor deposition, dip coating, simple brush coating,
doping, etc. out of which the latest method is electrodeposition where an external
voltage is applied to the solution which affects the polarity of the desired electrode
and leads to the deposition of oxide on the electrode.
The synthesis of nanoparticles is done chemically under high-temperature conditions. Few scientists are also exploring the green synthesis pathway of nanoparticles
where the microorganism, S. oneidensis MR-1 is used as reducing bacteria which can
synthesis the nanoparticles of palladium Pd by reducing Pd
2+ to Pd
0 on its cell walls
and in its periplasmic spaces (Quan et al. 2018; Wu et al. 2018). The plant extract of
A.blitum (Sekar et al. 2019) and A. Indica (Muthukumar et al. 2019) are also been
used as reducing agents of the synthesis of nanoparticles. As depicted in Table 1 all
the anode materials from graphite to carbon felt support the coating of nanoparticles.
The table also summarizes that use of nanoparticles is not subjected to any specific
design of MFC; it is used in both dual-chambered as well as single-chambered MFC
design.
The primitive goal of power enhancement is achieved with the coating of nanoparticles but the second parameter of wastewater treatment is also not a neglected aspect.
The researchers have achieved treatment of pharmaceutical, (Xu et al. 2018) dairy
(Sekar et al. 2019) as well as domestic wastewater (Mohamed et al. 2018a, b) using
these nanoparticles coated bioanodes. Thus, this approach is promising for both
fronts.
6 Future Prospects
Most of the power enhancement has been achieved and studied in laboratory scale
reactors. The research in this field has yet to be applied in field. In one such study
of benthic microbial fuel cell (BMFC) coating of cerium (Ce) nanoparticles was
applied which resulted in the enhancement of power density (Pushkar et al. 2018).
The need to apply the nanoparticles directly in field condition may face challenges
like loss of nanoparticles in the environment, durability and stability of coating, and
biocompatibility of these particles. The synthesis of nanoparticles through green
pathway is also under consideration. The potential of nanoparticles for the MFC
reactors can fix the minimum use of materials, good growth of biofilm, and better
surface area for electron reception.