Materiais para o ânodo
O contato na:
Morgan Advanced Materials Morganite Brasil LTDA
parou de responder depois de eu pedir orçamento e amostra de feltro de carbono. Ano passado obtive cotação com a Mersen no Brasil, mas o preço foi proibitivo. Temos de considerar seriamente um plano B para o ânodo. Da tese do David Pinto ("tese francesa"):
1.5.1.1. Carbon-based materials. Carbon rods and carbon sheets (flat graphite) are widely used as anodic electrodes in MFC due to their high conductivity, biocompatibility, non-toxicity, chemical stability and low sensibility to corrosion. There are accessible, easy to use and cheap [50,117–119] . To enhance bacterial adhesion, rods are gently abraded to improve their roughness. Main drawbacks of carbon rods and sheets are due to their low specific surface area and low porosity. However, if compactness is not mandatory, inexpensive and mechanically resilient carbon rods and sheets remain materials of choice. Also, carbon rods are commonly considered as model materials [120] .
A ref. 119 é: https://doi.org/10.1016/j.electacta.2008.03.032
Performance of non-porous graphite and titanium-based anodes in microbial fuel cells
"the bio-anode performance decreased in the order roughened graphite > Pt-coated titanium > flat graphite > uncoated titanium"
The current density of the non-porous bio-anodes, except for the uncoated titanium anode, was comparable to the reported current densities of porous materials when normalized to the projected surface area
The anodes were made of four different materials: flat graphite, Al2O3-blasted graphite (further called: roughened graphite) (both MR200, gas tight impregnated, from Müller & Rössner GmbH & Co., Troisdorf, Germany), Pt-coated titanium, and uncoated titanium (both from Magneto Special Anodes BV, Schiedam, The Netherlands).
(All four cathodes were flat graphite plates (Müller & Rössner GmbH & Co., Troisdorf, Germany).)
1.5.1.3. Metallic and metal coated materials.
precious metals (platinum, gold [151,152] ) or chemically stable metals in MFC cycling condition (titanium [119] , stainless steel [153] ) may be adapted as anode electrode. In 2008, Dumas et al. indicated lower efficiency of stainless steel plate electrodes compared to graphite electrodes in MFC (G. sulfurreducens) due to lower average surface roughness and non-optimized biofilm/electrode interface [154] . By replacing stainless steel plate by a stainless steel micro-structured grid, Pocaznoi dramatically increase MFC performance reaching equivalent or higher performance rather than carbon cloth, demonstrating the interest of using stainless steel-based electrodes [153] .
A ref. 153 é: https://doi.org/10.1039/C2EE22429A
Stainless steel electrodes were of superaustenitic grade (254SMO, Outokumpu, UNS31254, composition Cr 19.9%; Ni 17.8%; Mo 6.0%; N 0.2%; C 0.01%; Fe complement). The 2.5 cm2 electrodes were electrically connected with a 2 mm diameter screwed titanium wire. The micro-structured surfaces with Ra = 5 μm were obtained by sandblasting.
(Stainless steels have already proved to be efficient in designs for microbial cathodes used in MFCs and related technologies. Immersed in aerated marine seawater, stainless steel cathodes allowed the development of microbial biofilms that exhibited high catalytic properties for oxygen reduction7 and have been implemented in fuel cells.8)