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Carbon-coated Li2MoO4 hexagonal hollow nanotubes were fabricated via a facile sol-gel method involving the solution synthesis of Li2MoO4 with subsequent annealing under an inert atmosphere to decompose the organic carbon source. To the best of our knowledge, this is the first report on the synthesis of Li2MoO4 nanotubes. More significantly, we have found that Li2MoO4 can be used as an anode material for lithium-ion batteries (LIBs). When evaluated as an anode material, the carbon-coated Li2MoO4 hollow nanotubes show an excellent electrochemical performance with a high reversible capacity (∼550 mA h g(-1)) after 23 cycles, good rate capability and cycling stability. Meanwhile, carbon-free Li2MoO4 sample, fabricated via a solid state reaction, was also prepared for comparison. The Li storage mechanism has been investigated in-detail by advanced XPS, in situ XRD and HRTEM.

Dissolved organic phosphorus (DOP) has a dual role in the surface ocean as both a product of primary production and as an organic nutrient fueling primary production and nitrogen fixation, especially in oligotrophic gyres. Though poorly constrained, understanding the geographic distribution and environmental controls of surface ocean DOP concentration is critical to estimating distributions and rates of primary production and nitrogen fixation in the global ocean.Here we pair DOP concentration measurements with a metric of phosphate (PO4 3-) stress (P*), and satellite-based chlorophyll a concentrations and iron stress estimates to explore their relationship with upper 50 m DOP stocks. Our results show that PO4 3and iron stress work together to control surface DOP concentrations at basin scales. Specifically, upper 50 m DOP stocks decrease with increasing phosphate stress, while alleviated iron stress leads to either surface DOP accumulation or loss depending on PO4 3availability. Our work suggests an interdependence between DOP concentration, inorganic nutrient ratios, and iron availability, and establishes a predictive framework for DOP distributions in the global surface ocean.

The identity and rearrangements of substrate water molecules in photosystem II (PSII) water oxidation are of great mechanistic interest and addressed herein by comprehensive analysis of NH/NH binding. Time-resolved detection of O formation and recombination fluorescence as well as Fourier transform infrared (FTIR) difference spectroscopy on plant PSII membrane particles reveals the following. (1) Partial inhibition in NHCl buffer occurs with a pH-independent binding constant of ∼25 mM, which does not result from decelerated O formation, but from complete blockage of a major PSII fraction (∼60%) after reaching the Mn(IV) (S) state. (2) The non-inhibited PSII fraction advances through the reaction cycle, but modified nuclear rearrangements are suggested by FTIR difference spectroscopy. (3) Partial inhibition can be explained by anticooperative (mutually exclusive) NH binding to one inhibitory and one non-inhibitory site; these two sites may correspond to two water molecules terminally bound to the "dangling" Mn ion. (4) Unexpectedly strong modifications of the FTIR difference spectra suggest that in the non-inhibited PSII, ammonia binding obliterates the need for some of the nuclear rearrangements occurring in the S-S transition as well as their reversal in the O formation transition, in line with the carousel mechanism [Askerka, M., et al. (2015) Biochemistry 54, 5783]. (5) We observe the same partial inhibition of PSII by NHCl also for thylakoid membranes prepared from mesophilic and thermophilic cyanobacteria, suggesting that the results described above are valid for plant and cyanobacterial PSII.

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