Design and operation of microbial fuel cells for sustained electric power generation from sugar industry effluents.

The DAH proton source assisted Fe2O3–TiO2 system exhibits exceptional photocatalytic activity and stability for hydrogen generation by a water-splitting reaction.

The present study reports about the fabrication of a three-dimensional (3D) macroporous steel-based scaffold as an anode to promote specifically bacterial attachment and extracellular electron transfer to achieve power density as high as 1184 mW m–2, which is far greater than that of commonly used 3D anode materials. The unique 3D open macroporous configuration of the anode and the microstructure generated by the composite coating provide voids for the 3D bacterial colonization of electroactive biofilms. This is attributed to the sizeable interfacial area per unit volume provided by the 3D corrugated electrode that enhanced the electrochemical reaction rate compared to that of the flat electrode, which favors the enhanced mass transfer and substrate diffusion at the electrode/electrolyte interface and thereby increases the charge transfer by reducing the electrode overpotential or interfacial resistance. In addition, bacterial infiltration into the interior of the anode renders large reaction sites for substrate oxidation without the concern of clogging and biofouling and thereby improves direct electron transfer. A very low overpotential (−27 mV) with a very low internal resistance (7.104 Ω cm2) is achieved with the fabricated microbial fuel cell (MFC) that has a modified 3D corrugated electrode. Thus, easier and faster charge transfer at the electrode–electrolyte interface is confirmed. The study presents a revolutionary practical approach in the development of highly efficient anode materials that can ensure easy scale-up for MFC applications.

The present paper reports for the first time the development and application of novel Zn wetted CeO 2 (Zn/ CeO 2 ) composite galvanic zinc coating to combat microbial induced corrosion (MIC). Zinc metal−metal interaction causes the effective incorporation of composite into the galvanic coating and accordingly increases the active sites for antibiofouling activity. The developed coatings are explored for their anticorrosion/antibiofouling characteristics toward MIC induced by cultured seawater consortia. Enhanced antibiofouling activity of the composite galvanic coating is achieved due to the tuned content of 28 wt % Zn and 34 wt % of Ce. High charge transfer resistance as high as 4.0 × 10 14 Ω cm 2 and low double layer capacitance as low as 3.99 × 10 −8 F are achieved by tuning the structure and composition of the coating. The synergistic effect of Zn and Ce ensures the stability and corrosion resistance of the coatings in a corrosive bacterial environment. Evident decreases in the bacterial attachment and biofilm formation are illustrated using antibiofouling assay. The antibiofouling activity is attributed to the effective reduction of Ce 4+ to Ce 3+ and the shuttling characteristics of oxidation state of CeO 2 . This impairs the cellular respiration and results in bacterial death. Thus, it can be used as an effective coating to protect the steel based equipment in corrosive marine environments to combat marine microorganisms and their interactions. The present study also paves the scope for exploration of similar effective protective systems.

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