Janus type Water-Splitting Catalysts have attracted highest attention as a tool of choice for solar to fuel conversion. AISI Ni 42 steel was upon harsh anodization converted in a bifunctional electrocatalyst. Oxygen evolution reaction-(OER) and hydrogen evolution reaction (HER) are highly efficiently and steadfast catalyzed at pH 7, 13, 14, 14.6 (OER) respectively at pH 0, 1, 13, 14, 14.6 (HER). The current density taken from long-term OER measurements in pH 7 buffer solution upon the electro activated steel at 491 mV overpotential (η) was around 4 times higher (4 mA/cm 2 ) in comparison with recently developed OER electrocatalysts. The very strong voltagecurrent behavior of the catalyst shown in OER polarization experiments at both pH 7 and at pH 13 were even superior to those known for IrO 2 -RuO 2 . No degradation of the catalyst was detected even when conditions close to standard industrial operations were applied to the catalyst. A stable Ni-, Fe-oxide based passivating layer sufficiently protected the bare metal for further oxidation. Quantitative charge to oxygen-(OER) and charge to hydrogen (HER) conversion was confirmed. High resolution XPS spectra showed that most likely γ−NiO(OH) and FeO(OH) are the catalytic active OER and NiO is the catalytic active HER species.

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With the focus on intergranular crack propagation of Ni-base superalloys at high temperatures, a failure mechanism is discussed that seems to be due to a generic phenomenon: dynamic embrittlement. Under the influence of a tensile stress, an embrittling species is moved into the grain boundaries by grain-boundary diffusion, giving rise to local decohesion ahead of an intergranular crack tip. A very similar crack propagation behaviour was observed for S-induced intergranular cracking of low-alloy steels, Cu-Cr alloys, and for Sn-induced cracking of Cu-Sn model alloys, where the embrittling element coming from the bulk segregates at the grain boundary, as well as for O-induced cracking of Cu-Be and Ni-base alloys, where the embrittling element comes from the atmosphere. A qualitative steady-state model of the dynamic embrittlement mechanism suggests that the dynamic embrittlement damage zone lies in the nanometre range ahead of the crack tip. Mechanical testing of grain-boundary-engineering-type processed and bicrystalline specimens revealed strong interactions between the crystallographic misorientation relationship and the dynamic embrittlement mechanism, whereby special grain boundaries with a high fraction of coincident lattice sites seem to have a particularly high resistance against quasi-brittle intergranular fracture by dynamic embrittlement.

In spite of the drastic oil price collapse in the second half of 2014 resulting in a price below 30 $/barrel in January 2016 1 , the exploration of promising renewable energy sources for the Abstract: Water splitting allows the storage of solar energy into chemical bonds (H 2 +O 2 ) and will help to implement the urgently needed replacement of limited available fossil fuels. Particularly in neutral environment electrochemically initiated water splitting suffers from low efficiency due to high overpotentials (η) caused by the anode. Electro-activation of X20CoCrWMo10-9, a Co-based tool steel resulted in a new composite material (X20CoCrWMo10-9//Co 3 O 4 ) that catalyzes the anode half-cell reaction of water electrolysis with a so far-, unequalled effectiveness. The current density achieved with this new anode in pH 7 corrected 0.1 M phosphate buffer is over a wide range of η around 10 times higher compared to recently developed, up-to-date electrocatalysts and represents the benchmark performance advanced catalysts show in regimes that support water splitting significantly better than pH 7 medium. X20CoCrWMo10-9//Co 3 O 4 exhibited electrocatalyticproperties not only at pH 7, but also at pH 13, which is much superior to the ones of IrO 2 -RuO 2 , single-phase Co 3 O 4 -or Fe/Ni-based catalysts. Both XPS and FT-IR experiments unmasked Co 3 O 4 as the dominating compound on the surface of the X20CoCrWMo10-9//Co 3 O 4 composite. Upon a comprehensive dual beam FIB-SEM (focused ion beam-scanning electron microscopy) study we could show that the new composite does not exhibit a classical substrate-layer structure due to the intrinsic formation of the Co-enriched outer zone. This structural particularity is basically responsible for the outstanding electrocatalytic OER performance.2 future is one of the significant challenges for scientists and engineers concerned with energy issues research. Splitting of water into hydrogen and oxygen by exploiting solar energy transforms water to an inexhaustible and environmental friendly fuel source 2,3,4,5,6,7,8,9 .Electrocatalytically initiated hydrogen-and oxygen formation from water is considered an important realization of this solar to fuel conversion route 10,11,12 but is typically hampered by the high overpotentials oxygen evolution on the anode side goes with 13,14 . This is particularly true when the electrochemical cleavage of more or less untreated water is intended-; hence, when the splitting procedure is carried out at neutral pH value. 17,18,19,20,21,22,23,24 . Scheme 1 gives some idea of the position of current heterogeneous catalysts in terms of their efficiency regarding OER in neutral regime. The significant improvement of the voltage-current behavior can be taken from both-, the non-steady state ( Figure 1a) as well as the steady state polarization (Figure 1b) experiments. Results OER properties in neutral mediumThe CV of sample Co-300 shows along the entire curve substantially stronger current to voltage ratio than the CV of sample Co and reached, at the upper...

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