Herein, we first systematically studied the impact of different transition metalbased co-catalysts towards the photocatalytic water reduction, when they are physically mixed with the visible-light active MIL-125-NH2. All co-catalyst/MIL-125-NH2 photocatalytic systems were found to be highly stable after photocatalysis, with the NiO/MIL-125-NH2 and Ni2P/MIL-125-NH2 systems exhibiting high hydrogen (H2) evolution rates of 1084 and 1230 μmol h-1 g-1 , respectively. Secondly, we investigated how different electron donors affected the stability and H2 generation rate of the best Ni2P/MIL-125-NH2 system and found that triethylamine fulfils both requirements. We then replaced the electron donor with rhodamine

Ap yrene-based metal-organic framework (MOF) SION-8 captured iodine (I 2 )v apor with ac apacity of 460 and 250 mg g À1 MOF at room temperature and 75 8C, respectively.S ingle-crystal X-ray diffraction analysisa nd van-der-Waals-correctedd ensity functional theory calculations confirmed the presence of I 2 molecules within the pores of SION-8 and their interaction with the pyrene-based ligands.T he I 2 -pyrene interactions in the I 2 -loaded SION-8 led to a1 0 4 -fold increase of its electrical conductivity compared to the bare SION-8.U pon adsorption, ! 95 %o fI 2 molecules were incarcerated and could not be washed out, signifying the potentialofSION-8 towardst he permanent capture of radioactiveI 2 at room temperature.Radioactivei sotopes of iodine, mainly 129 Ia nd 131 I, are produced in nuclear-related processes and maya ccidentally be released into the atmosphere, as witnessed in Fukushima and Chernobyl,c onstituting am ajor hazard to humans and the environment. Isotope 131 Ih as ar adioactive decay half-life of about eight days, emits b À and g rays, and concentrates in the thyroid gland of the person exposed to the radioactive source causing thyroidc ancer.T he 129 Ii sotope has am uch longerl ife, with ah alf-lifeo f1 5.7 million years, and poses al ong-term disposalr isk. Capturing radioactive iodine is therefore necessary for safe nuclear wastes torage. [1] Wet scrubbing and the use of solid adsorbentsa re two general methodsf or iodine capture, with the latter being often preferred because it does not require the use of highly corrosive liquids. [1] The benchmark solid adsorbents for radioactive iodinec apture is thes ilver (Ag)-exchanged zeolitic mordenite, with an average I 2 -adsorption capacityo fa pproximately 100-130 mg g À1 mordernite at high temperatures (150-200 8C). [1, 2] In recenty ears, metal-organic frameworks (MOFs), which are crystalline materials formed by linkingm etal ions or metal clusters with multi-topic organic ligands, [3] have emergeda sp romising adsorbents for I 2 captured ue to their high porosity [4] and chemicaltunability. [5] For example, our group has previouslyreportedahigh I 2 vapor uptake by HKUST-1 and ZIF-8,a nd their composites with polymers, reaching 538 mg g À1HKUST-1 at 75 8C.[6] The Nenoff group and the Thallapally group have studied the adsorption of I 2 on HKUST-1a nd SBMOFs, respectively,i nt he presence of humidity. [7] However,t he degradation of these MOFs in water,a nd the leaching of I 2 from the I 2 -loaded MOFs when they are in contact with water and common organic solvents,g ive rise to considerable concerns regarding the potential of theseM OFs for I 2 capture. The I 2 leachingi st hought to be due to the weak interaction between the I 2 molecules with the pore surface of the MOF.Here, we report aM OF named SION-8,w hich is based on the employment of 1,3,6,8-tetrakis(p-benzoic acid)pyrene (H 4 TBAPy)a nd Ca II , [8] that can efficientlyc aptureI 2 vapor at both room temperature and at 75 8C. The strategy for I 2 capture is based on the well-know...

Metallic electrodes based on iron, nickel, and/or cobalt have re-emerged as promising cost-effective anodes for the alkaline oxygen evolution reaction (OER) due to their simplicity and their in situ formation of a highly active oxy-hydroxide surface catalyst layer, which exhibits state-of-the-art overpotentials for the OER. However, the effect of alloy composition has not been systematically studied. Herein, using metallic anodes with defined Fe–Ni–Co atomic ratios prepared via arc melting, we report the relationship between the initial alloy composition, the OER performance, and the emergent active catalyst composition. After 50 h operation at 0.5 A cm–2 the most active initial alloys (having a moderate amount of cobalt <40 at. %, an iron proportion between 30 and 80 at. % and a nickel ratio below 60 at. %) gave average overpotentials for 10 mA cm–2 ca. 300–320 mV and Tafel slopes of 35–50 mV dec–1. Iron and nickel-rich alloys performed poorer. The oxyhydroxide OER catalyst formed on the anode surface generally showed an increased concentration of Co and Ni and a depletion of Fe compared to the initial metal composition, giving the most active OER catalyst at a composition of Ni and Co of ca. 40 at. % with Fe at ca. 20 at. %. However, the initial alloy composition of Fe12.5Co12.5Ni75, showed a nearly invariant surface metal composition, indicating this as the most stable composition. Further analysis of the surface identified no correlation of the mass of metals leached from the anode surface, the electrochemically active surface area, or the presence of active Ni2+/3+ redox surface sites to the OER performance suggesting these factors do not influence the results.

BackgroundLiCoO2 is one of the most used cathode materials in Li-ion batteries. Its conventional synthesis requires high temperature (>800 °C) and long heating time (>24 h) to obtain the micronscale rhombohedral layered high-temperature phase of LiCoO2 (HT-LCO). Nanoscale HT-LCO is of interest to improve the battery performance as the lithium (Li+) ion pathway is expected to be shorter in nanoparticles as compared to micron sized ones. Since batteries typically get recycled, the exposure to nanoparticles during this process needs to be evaluated.ResultsSeveral new single source precursors containing lithium (Li+) and cobalt (Co2+) ions, based on alkoxides and aryloxides have been structurally characterized and were thermally transformed into nanoscale HT-LCO at 450 °C within few hours. The size of the nanoparticles depends on the precursor, determining the electrochemical performance. The Li-ion diffusion coefficients of our LiCoO2 nanoparticles improved at least by a factor of 10 compared to commercial one, while showing good reversibility upon charging and discharging. The hazard of occupational exposure to nanoparticles during battery recycling was investigated with an in vitro multicellular lung model.ConclusionsOur heterobimetallic single source precursors allow to dramatically reduce the production temperature and time for HT-LCO. The obtained nanoparticles of LiCoO2 have faster kinetics for Li+ insertion/extraction compared to microparticles. Overall, nano-sized LiCoO2 particles indicate a lower cytotoxic and (pro-)inflammogenic potential in vitro compared to their micron-sized counterparts. However, nanoparticles aggregate in air and behave partially like microparticles.Electronic supplementary materialThe online version of this article (doi:10.1186/s12951-017-0292-3) contains supplementary material, which is available to authorized users.