Arming Amorphous NiMoO4 on Nickel Phosphide Enables Highly Stable Alkaline Seawater Oxidation.

Seawater electrolysis holds tremendous promise for the generation of green hydrogen (H2 ). However, the system of seawater-to-H2 faces significant hurdles, primarily due to the corrosive effects of chlorine compounds, which can cause severe anodic deterioration. Here, a nickel phosphide nanosheet array with amorphous NiMoO4 layer on Ni foam (Ni2 P@NiMoO4 /NF) is reported as a highly efficient and stable electrocatalyst for oxygen evolution reaction (OER) in alkaline seawater. Such Ni2 P@NiMoO4 /NF requires overpotentials of just 343 and 370 mV to achieve industrial-level current densities of 500 and 1000 mA cm-2 , respectively, surpassing that of Ni2 P/NF (470 and 555 mV). Furthermore, it maintains consistent electrolysis for over 500 h, a significant improvement compared to that of Ni2 P/NF (120 h) and Ni(OH)2 /NF (65 h). Electrochemical in situ Raman spectroscopy, stability testing, and chloride extraction analysis reveal that is situ formed MoO4 2- /PO4 3- from Ni2 P@NiMoO4 during the OER test to the electrode surface, thus effectively repelling Cl- and hindering the formation of harmful ClO- .

Enhanced removal performance of zero-valent iron towards heavy metal ions by assembling Fe-tannin coating.

Heavy metals (HMs) pose serious threats to both human and environmental health and therefore, effective and low-cost techniques to remove HMs are urgently required. Here we report a facile Fe-tannin coating method for zero-valent iron (ZVI) including nanoparticles (nZVI) and foam (Fefoam), and demonstrate that the generated Fe-tannin coating would remove the inherent passive iron oxide shell of ZVI and provide channels for the galvanic replacement reaction between ZVI and HM ions. Electrochemical characterizations demonstrate that the Fe core of the modified ZVI materials could be easily oxidized and transfer electrons to HM ions owing to the facile mass transport and charge transfer. In 40 min, nZVI@Fe-TA exhibits excellent performances for Cd(II), Ni(II), Pb(II), Hg(II), Cu(II) and Cr(VI) removal, with the apparent removal rate constants of 0.083, 0.085, 0.083, 0.073, 0.092 and 0.078 min-1, respectively. It is found that the surface area normalized rate constants of nZVI@Fe-TA are 4-7 times higher than that of nZVI@Fe2O3 counterpart, suggesting that the improved HM removal reactivity of nZVI@Fe-TA is derived from the surface modification. Moreover, nZVI@Fe-TA has advantages in resisting interference and in the simultaneous removal of different HM ions. Under a 30 min hydraulic retention time, Fefoam@Fe-TA could remove 98% HMs in the successive process. For real electroplating wastewater, Fefoam@Fe-TA exhibits excellent performance for Cr(VI) and Ni(II) removal, producing effluent of stable quality that meets local emission regulation. This study provides a facile strategy to remove the inherent passive iron oxide shell and enhance the HM removal reactivity for ZVI materials.

Poly[di-µ(3)-chlorido-di-µ(2)-chlorido-{µ(4)-N,N,N',N'-tetra-kis-[(diphenyl-phosphan-yl)meth-yl]benzene-1,4-diamine-κ(4)P:P':P'':P'''}tetra-copper(II)].

In the title complex, [Cu(4)Cl(4)(C(58)H(52)N(2)P(4))](n), four Cu(II) atoms are held together via two doubly bridging and two triply bridging chlorides, forming a stair-like Cu(4)Cl(4) core having crystallographically imposed inversion symmetry, while the benzene-1,4-diamine ligand (with a crystallographic inversion center at the centroid) acts in a tetra-dentate coordination mode, bridging two adjacent Cu(4)Cl(4) cores, resulting in a chain along the a-axis direction. One Cu atom has a distorted tetra-hedral geometry, coordinated by one P atom, one µ(2)-Cl and two µ(3)-Cl atoms, while the second Cu atom adopts a trigonal geometry, coordinated by one P atom, one µ(2)-Cl and one µ(3)-Cl atoms.