Nickel

About: Nickel is a research topic. Over the lifetime, 79308 publications have been published within this topic receiving 1210058 citations. The topic is also known as: Ni & element 28.

Metal-alane adducts with zero-valent nickel, cobalt, and iron.

Abstract: Coordination complexes that pair a zero-valent transition metal (Ni, Co, Fe) and an aluminum(III) center have been prepared. They add to the few examples of structurally characterized metal alanes and are the first reported metallalumatranes. To understand the M-Al interaction and gauge the effect of varying the late metal, the complexes were characterized by X-ray crystallography, electrochemistry, UV-Vis-NIR and NMR spectroscopies, and theoretical calculations. The M-Al bond strength decreases with varying M in the order Ni > Co > Fe.

Comparison of two serpentine species with different nickel tolerance strategies.

Abstract: The effects of nickel were studied in two serpentine species with different metal tolerance strategies:Silene italica L., which limits nickel uptake and translocation, andAlyssum bertolonii Desv., a serpentine endemic, which accumulates nickel mostly in the leaves. InS. italica, nickel 7.5 μM inhibited root growth and depressed mitotic activity in root tips. Peroxidase activity and phenol concentration both in roots and shoots were increased; under the same conditions nickel did not produce any relevant effect onA. bertolonii.

Recent advances in phase, size, and morphology-oriented nanostructured nickel phosphide for overall water splitting

Abstract: Currently, world is dealing with two major hurdles towards a prosperous economy, i.e., energy crisis and environmental pollution, which challenge the development and growth of the living society. In this regard, semiconductor-oriented heterogeneous photocatalysis, electrocatalysis, and photoelectrocatalysis via fuel cell technology are green and sustainable technologies that have been receiving wide attention by the scientific community for tackling these two issues. In addition, in the present scenario, the synthesis of cost-effective and robust catalysts with high stability, corrosion resistance in any medium, and size and morphology oriented in the micro and nanoscale is a hot topic of research. Therefore, transition metal phosphides (TMPs) and their composite-based catalysts are extensively used in these fields, replacing previously used noble metals such as Pt, Au, and Ag due to scarcity, instability, and high price. Predominantly, nickel phosphide-based materials among all TMPs have proven to be excellent catalysts regarding these fields of application. The metal–phosphorus bonding, basically the Ni–P bonding present in the catalyst, and its resemblance with the [NiFe] hydrogenase makes it more stable and resistive. Several phases of nickel phosphides are available with different lattice structures. Moreover, according to their metal and phosphorus proportion, they can be divided in two categories as metal-rich nickel phosphides and phosphorus-rich nickel phosphides. With respect to this, their activities are also reflected by their elemental contents; the phosphorus-rich nickel phosphides are excellent in electrocatalytic hydrogen evolution reactions (HER), whereas metal-rich nickel phosphides are excellent in electrocatalytic oxygen evolution (OER). However, some metal-rich nickel phosphides with high P/Ni ratio, i.e., Ni5P4, show better activity towards HER because of the high P content. The Ni2P phase also plays an active role in both HER and OER, though it belongs to the metal-rich phase. This shows good catalytic behavior towards HER due to presence of well-defined exposed facets and proper proportion of Ni and P atoms. Furthermore, different types of composites are still being developed by modifying their morphology and size through different synthetic strategies with the expectation of more enhanced activity. This review gives an overview of the design and development of nanostructured nickel phosphide-based materials and their recent significant trends in electrocatalytic, photoelectrocatalytic, and photocatalytic water splitting reactions. Moreover, we present the state-of-art various nickel phosphide materials in last five years, which highlight challenges and future prospects involving some critical issues in these emerging fields that await further exploration, and opportunities in the present and future research.