Cobalt

About: Cobalt is a research topic. Over the lifetime, 69899 publications have been published within this topic receiving 1242058 citations. The topic is also known as: Co & Element 27.

Formation of Ni-Co-MoS2 Nanoboxes with Enhanced Electrocatalytic Activity for Hydrogen Evolution.

Abstract: Nickel and cobalt incorporated MoS2 nanoboxes are synthesized via the reaction between Ni-Co Prussian blue analogue nanocubes and ammonium thiomolybdate. Due to the structural and compositional advantages, these well-defined nanoboxes manifest enhanced electrochemical activity as an electrocatalyst for hydrogen evolution reaction.

Visible light driven photoelectrochemical water oxidation on nitrogen-modified TiO2 nanowires.

Abstract: We report hydrothermal synthesis of single crystalline TiO(2) nanowire arrays with unprecedented small feature sizes of ~5 nm and lengths up to 4.4 μm on fluorine-doped tin oxide substrates. A substantial amount of nitrogen (up to 1.08 atomic %) can be incorporated into the TiO(2) lattice via nitridation in NH(3) flow at a relatively low temperature (500 °C) because of the small cross-section of the nanowires. The low-energy threshold of the incident photon to current efficiency (IPCE) spectra of N-modified TiO(2) samples is at ~520 nm, corresponding to 2.4 eV. We also report a simple cobalt treatment for improving the photoelectrochemical (PEC) performance of our N-modified TiO(2) nanowire arrays. With the cobalt treatment, the IPCE of N-modified TiO(2) samples in the ultraviolet region is restored to equal or higher values than those of the unmodified TiO(2) samples, and it remains as high as ~18% at 450 nm. We propose that the cobalt treatment enhances PEC performance via two mechanisms: passivating surface states on the N-modified TiO(2) surface and acting as a water oxidation cocatalyst.

Inter-ligand reactions: in situ formation of new polydentate ligands

Abstract: Two ligands have been synthesized by derivatisation of cyanuric chloride: 6-(diethylamino)-2,4-disulfanyl-1,3,5-triazine (H2SSta) 1 and 6-(diethylamino)-2-hydroxo-4-sulfanyl-1,3,5-triazine (H2OSta) 2 have been characterised by X-ray crystallography, which shows intermolecular hydrogen bonding in the solid state, leading to dimers of 1 and ribbons of 2. On reaction with metal salts both ligands undergo oligomerisation reactions. Compound 1 reacts with nickel chloride to form a mononuclear complex, [Ni{(Sta)S(S2ta)}] 3. In 3 two triazine ligands have reacted, to form a tetradentate ligand in which two triazine rings are bridged by a sulfur group, with a co-ordinated disulfide group present on one ring and a co-ordinated thiolate on the second. Compound 2 reacts with cobalt(II) chloride to form a cage complex, [Co6NaO(OStaH)7{S(Ota)2}2(O2CPh)2(H2O)2] 4. This complicated structure contains two polydentate ligands formed by linking triazine groups through a bridging sulfur. The cage contains four cobalt(II) and two cobalt(III) sites which are assigned by bond length considerations. The compound [Co(OSta)3] 5 co-crystallises with 4, and its structure has also been determined.