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Abstract: A [4Fe–4S]1+ cluster-containing protein activates 2-hydroxyisocaproyl-CoA dehydratase by an ATP-driven electron transfer. The activator has been proposed to change its conformation by MgATP similarly to nitrogenase Fe-protein. Iron chelation by bathophenanthroline removed the reduced [4Fe–4S]1+ cluster from the activator in an ATP-dependent manner (rate, v =0.128±0.004min−1; K m =21±1μM); with ADP no chelation was observed (v <0.001min−1). Chelation of the oxidised [4Fe–4S]2+ cluster occurred faster with ADP (v =0.34±0.05min−1) than with ATP (v =0.132±0.005min−1). The data indicate that reduction of the activator and binding of ATP induce conformational changes necessary to transfer the electron to the dehydratase. Interaction of both proteins promotes ATP hydrolysis (K m =0.5±0.1μM). [Copyright &y& Elsevier]

[Display omitted] • The correlation between the power generation and pollutant degradation was determined. • Activated carbon (AC) improves the pollutant transfer from liquid phase to biofilm. • Modified ruthenium (Ru) accelerates the electron transfer from biofilm to anode. • The Ru-AC bioanode enhances chlorobenzenes removal and power generation. • Ru and AC together promote the conversion of chlorophenols to organic acids. Microbial fuel cell (MFC) is a promising device for water decontamination and energy generation. However, the correlation between power generation and pollutant degradation has not been clarified. Herein, a ruthenium–activated carbon (Ru–AC) bioanode was constructed for chlorobenzenes (CBs) treatment. The pollutant tolerance was improved by Ru–AC anode, and the minimum removal efficiencies of CB and ortho -dichlorobenzene (o -DCB) reached 75.1 % and 69.3 %, respectively, which were considerably higher than those of other MFCs (16.3 %–39.7 %). Correspondingly, the maximum output voltage reached 360.7 mV for the Ru–AC anode, whereas the values obtained from others reached 45.2–149.6 mV. Interaction models were introduced to quantify the relationship between power generation and pollutant degradation. The conversion of highly toxic chlorophenols to organic acids could be accelerated by boosting the mass and electron transfer, thereby simultaneously enhancing CBs removal and power generation. This work provided important insights into pollutant-powered MFC development. [ABSTRACT FROM AUTHOR]

[Display omitted] A self-standing NiFe-LDH@CoS x /NF electrocatalyst is developed by electrodepositing amorphous CoS x onto NiFe-LDH nanosheet arrays, which shows highly efficient performance towards overall water splitting. • A novel self-standing 3D NiFe-LDH@CoS x /NF bifunctional electrocatalyst is fabricated. • Integration of HER-active CoS x and OER-effective NiFe-LDH endows dual-function activity. • The NiFe-LDH@CoS x /NF assembly requires ultralow overpotentials for both HER and OER. • Interface interactions and synergistic effect favor the both HER and OER activity. Electrocatalytical water splitting to produce hydrogen energy is a promising green technology to solve energy crisis and environmental issues. The development of highly efficient and low-cost electrocatalysts is crucial for mass hydrogen production from water splitting. We newly assemble the self-standing 3D NiFe-LDH@CoS x /NF bifunctional electrocatalysts, via the electrodeposition of amorphous CoS x on two-dimensional (2D) NiFe-LDH nanosheets which are supported by porous nickel foam (NF). The integration of HER-active electrocatalyst of CoS x with outstanding OER catalyst of NiFe-LDH guarantees the bifunctional electrocatalytic activity. Furthermore, the formation of the constructed interfaces between amorphous CoS x and NiFe-LDH nanosheets synergistically favors the electron transfer. Therefore, this novel NiFe-LDH@CoS x /NF hierarchical assembly needs ultralow overpotentials of 136 mV (for HER) and 206 mV (for OER) to afford the 10 mA cm−2 current density in alkaline medium (1 M KOH). An electrolyzer based on the NiFe-LDH@CoS x /NF produces an extremely low cell voltage (1.537 V) and good durability. This study offers a promising strategy for facile fabrication of low-cost electrocatalysts which boost the electrocatalytic performance for overall water splitting. [ABSTRACT FROM AUTHOR]