Ce-doping induces rapid electron transfer in a bimetallic phosphide heterostructure to achieve efficient hydrogen production.

Using electrochemical water splitting to generate hydrogen is considered a desirable approach, which is greatly impeded by the sluggish dissociation of H2O and adsorption and desorption of H*. Effective hydrogen production can be achieved by speeding up the chemical process with a suitable electrocatalyst. In this work, we designed and synthesized a rare earth element cerium (Ce) regulated iron-nickel bimetallic phosphide Ce-NiFeP@NF (here NiFeP represents Fe2P/NiP2) nanoarray with nanoflowers. For the hydrogen evolution reaction (HER), Ce-NiFeP@NF only needs an overpotential of 106 mV to provide a current density of 10 mA cm-2, compared to NiFeP@NF (175 mV@10 mA cm-2). This self-supported electrocatalyst Ce-NiFeP@NF with a composite morphology exhibits excellent performance in the HER. Specifically, the introduction of Ce promotes the electron transfer process at the Fe2P/NiP2 heterojunction interface and the Ce-NiFeP@NF nanocomposite structure with nanoflowers has a larger electrochemically active specific surface area, which is more conducive to improving the intrinsic catalytic activity. Also, a dual-electrode alkaline electrolytic cell (Ce-NiFeP@NF functions as both the anode and the cathode) operates with a cell voltage of only 1.56 V to achieve a current density of 10 mA cm-2. The synergistic effect of rare earth element doping and heterojunction engineering can improve the morphology of intrinsic catalysts to achieve more efficient electrochemical water splitting for hydrogen production.

In situ activity of NAC11-7 roseobacters in coastal waters off the Chesapeake Bay based on ftsZ expression.

Determining in situ growth rates for specific bacterioplankton is of critical importance to understanding their contributions to energy and matter flow in the Ocean. Quantifying expression of genes central to cell division is a plausible approach for obtaining these measurements. In order to test this approach's assumptions, a quantitative PCR assay targeting the cell division gene ftsZ in the ubiquitous NAC11-7 group of the Rhodobacterales order of marine bacteria was developed. ftsZ genes and their corresponding mRNAs were measured in diel in situ samples and in parallel on-deck incubations. Strong correlations between ftsZ expression and gene abundance (R-squared = 0.62) were observed in situ. Rapid changes in NAC11-7 ftsZ gene copies suggested that different populations from different water types were sampled with a significant positive correlation between ftsZ expression and water temperature (R-squared = 0.68, P < 0.001). An outlier to this trend occurred at a single time point (9:00), which was remarkably consistent with a concomitant peak in ftsZ expression in on-deck incubations, suggesting the possibility of synchronous population growth.