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Using NaClO2 pretreated Calotropis gigantea fiber (CGF) as the bio-template, three N-polymer functionalized fibers were fabricated by in-situ growth of polydopamine (PDA), polyaniline (PAN) and poly(m-phenylenediamine) (PmPD) along the fiber. The resulting adsorbents were applied to remove perfluorooctanoic acid (PFOA) from water. The adsorption process reached equilibrium within 3 h, and the maximum adsorption capacity was 207.3–232.8 mg/g. Electrostatic attraction, hydrogen bond and hydrophobic interaction participated in the adsorption process. Three adsorbents could be well regenerated, and the recovered adsorbents maintained higher adsorption percentage (≥80%) after five adsorption-desorption cycles. Among three adsorbents, PAN-CGF displayed remarkable adsorption performance on perfluorochemicals removal.

All-metal self-supported cathodes, especially porous noble metals, are attractive alternatives for settling the issue of carbon- and binder-decomposition in Li–O2 batteries. However, the high cost of noble metals hinders their practical application. In the present study, nanoporous Ti foam is prepared using a molten Mg corrosion method for the first time. Electron microscope images demonstrate that, nanoporous Ti foam is obtained by treating Ti-Mo alloy plates in molten Mg at 650 °C for 3 hours. Then, the foam is coated with a layer of Au nanoparticles by cool-sputtering and used as self-supported Li–O2 battery cathodes. The nanoporous foam can decrease the consumption of gold markedly compared with traditional porous Au foam. Benefiting from the high stability, conductivity, and porosity of Ti foam, the Li–O2 batteries exhibit good durability (cycling 118 rounds at 1C rate within a 1000 mAh g−1 capacity limitation).

RuO2 modified TiO2 nanotube arrays, growing on Ti foams, are used as carbon and binder free cathodes for Li–O2 batteries. The micrometer pores in Ti foams and nanometer pores in TiO2 nanotubes supply facilitated transport channels for oxygen diffusing into/out of the catalysts in discharge and charge processes. The RuO2 catalyst exhibits outstanding catalytic active toward oxygen evolution reaction (OER), which leads the charge voltage maintaining around 3.7 V all through the battery cycling. The stability of TiO2/Ti support, abundant oxygen transport path and favorable catalytic activity of RuO2 toward OER enable the Li–O2 batteries exhibiting 130 cycle discharge/charge.

The hypothesis that the joint effects of predation and cyanobacteria favor the performance of small-bodied cladocerans relative to large-bodied species was tested using three competition experiments in a two-factor full-factorial design. The largebodied Daphnia pulex outcompeted the medium-bodied Simocephalus vetulus when fed a green alga Chlorella pyrenoidosa. However, the presence of the toxic cyanobacterium Microcystis aeruginosa and the coelenterate predator Hydra oligactis reversed the competitive outcome. Their joint effect was significant and contributed to the strongest dominance of S. vetulus. Similar dominance shifts were also observed in the competition between D. pulex and the small-bodied Bosmina longirostris, and in the competition between S. vetulus and B. longirostris. Life table and predation experiments showed that the order of sensitivity of three cladoceran species to Microcystis and to Hydra was the same as the order of competitive superiority in the absence of cyanobacteria. Therefore, cyanobacteria, predation and their joint effects are important drivers for competitive outcomes among cladocerans, potentially creating new opportunities for small-bodied species to dominate in a community. The present study underscores the importance of considering the combined effects of dietary palatability and predation on competitive dominance among herbivores, when predicting zooplankton responses to frequent cyanobacterial blooms.