ABSTRACT
External electric field has the potential to influence metabolic processes such as biological hydrogen production in microorganisms. Based on this concept, we designed and constructed an electroactive hybrid system for microbial biohydrogen production under an electric field comprised of polydopamine (PDA)-modified Escherichia coli (E. coli) and Ni foam (NF). In this system, electrons generated from NF directly migrate into E. coli cells to promote highly efficient biocatalytic hydrogen production. Compared to that generated in the absence of electric field stimulation, biohydrogen production by the PDA-modified E. coli-based system is significantly enhanced. This investigation has demonstrated the mechanism for electron transfer in a biohybrid system and gives insight into precise basis for the enhancement of hydrogen production by using the multifield coupling technology.
Subject(s)
Electrons , Escherichia coli , Hydrogen , Polymers , Escherichia coli/metabolism , Hydrogen/metabolism , Hydrogen/chemistry , Polymers/chemistry , Polymers/metabolism , Indoles/chemistry , Indoles/metabolism , Nickel/chemistry , Nickel/metabolism , Electron TransportABSTRACT
CdS nanoparticles were introduced on E. coli cells to construct a hydrogen generating biohybrid system via the biointerface of tannic acid-Fe complex. This hybrid system promotes good biological activity in a high salinity environment. Under light illumination, the as-synthesized biohybrid system achieves a 32.44 % enhancement of hydrogen production in seawater through a synergistic effect.
Subject(s)
Escherichia coli , Nanoparticles , Semiconductors , HydrogenABSTRACT
Perylene diimide derivatives (PDIs) are suitable ECL luminophore candidates with low triggering potentials and strong ECL signals for fundamental studies and practical applications. However, PDIs tend to aggregate, which affects their optical properties and limits their application in bio-imaging and bio-sensing fields. In this study, an ECL sensor is fabricated based on the layer-by-layer (LBL) assembly of N, N-bis(phosphonomethyl)-3,4,9,10-perylene diimide (PMPDI) and ZrIV ions on the surface of a mesoporous indium tin oxide (ITO) substrate. When six layers of PMPDI are immobilized on ITO, the resulting PMPDI6/ITO electrode shows maximum ECL intensity with K2S2O8 as a co-reactant in the potential range 0 to -0.5 V vs. Ag/AgCl. LBL assembly decreases the aggregation and increases the loading of PMPDI on the mesoporous ITO substrate, which stabilizes and amplifies the ECL signals. The ECL method exhibits excellent sensitivity and selectivity with good stability and reproducibility, when used to detect dopamine (DA) under optimal experimental conditions.
Subject(s)
Perylene , Dopamine , Electrodes , Luminescent Measurements/methods , Perylene/chemistry , Reproducibility of ResultsABSTRACT
Power plants emit sulfur dioxide (SO2) during combustion, which is typically removed via wet flue gas desulfurization, but this process produces numerous secondary pollutants. Ionic liquids (ILs) can potentially be used to remove SO2, but they suffer from poor mass transfer rates. Hydroxyl ammonium ILs are classical cheap ILs that contain electron-rich O and N sites that favor high absorption capacities. To accelerate mass transfer, two hydroxyl ammonium ILs, triethanolamine citrate and triethanolamine lactate, were immobilized on activated carbon (SILs) and used to capture SO2 from simulated flue gas. They exhibited excellent adsorption at low SO2 partial pressures due to the presence of a large gas-liquid interface. The molar adsorption ratios reached 7.65 and 2.40 mol/mol at 10 kPa SO2. The SILs possessed good SO2 selectivity in SO2/CO2 and SO2/O2 mixtures, because of the only 8% reduction in the total adsorption of SILs at 60 °C. And they exhibited excellent reversibility in which their total adsorption capacities were unaffected after 5 adsorption-desorption cycles. The mechanism analysis revealed that chemical adsorption was the major adsorption route, although physical adsorption also occurred. The main reactive sites included C-O and N-H groups in the ionic liquid. These SILs may potentially replace traditional chemical absorption materials for the separation of SO2 from flue gas.
