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An unprecedented spin cluster‐based network architecture {[NiII2(pdaa)(OH)2(H2O)]n (H2pdaa=1,4‐phenylene diacetic acid)}, comprising 1D linear chains of NiII ions crosslinked via Ni4O4 cubanes, forms under hydrothermal conditions; this 3D coordination network exhibits magnetic ordering at 23.9 K as well as a second magnetic ordering process at 2.8 K likely associated with a structural phase transition. [ABSTRACT FROM AUTHOR]

A series of composite photocatalysts based on CdS nanorods decorated with Cu/Ni hydroxides were prepared via deposition precipitation method at room temperature (total metal loading ≈ 3 wt%). The performance of these photocatalysts was evaluated for H 2 production through water dissociation reaction under direct sunlight. The 2.4Cu(OH) 2 0.6Ni(OH) 2 /CdS photocatalyst with a total 3 wt% nominal metal cocatalyst loading demonstrated an excellent hydrogen production activity of ~20 mmol h−1 g−1, that is 2 and 20 times greater than the benchmark Au/CdS and pristine CdS photocatalysts, respectively. Detailed analyses based on UV–Visible diffuse reflectance spectroscopy (DRS), X-ray diffraction (XRD), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), steady state photoluminescence (PL) and energy dispersive spectroscopy (EDS) suggested cocatalysts Cu/Ni hydroxides were transformed into their metallic states during photoreaction. Cu° was produced by the transfer of electrons due to the as available position of CdS conduction band (E° = 0.61 V) to surface Cu(OH) 2 nanoclusters (Cu(OH) 2 /Cu°, E° = 0.224 V) whereas Ni° was produced by the shift in conduction band level of CdS under continuous sunlight illumination (Ni(OH) 2 /Ni°, E° = 0.72 V). Based on these observations, the mechanism of hydrogen production from water splitting over Cu/Ni(hydroxides)-CdS was described. [Display omitted] • CdS nanorods decorated with Cu/Ni hydroxides are prepared. • The performance of these photocatalysts was evaluated for H 2 production. • The 2.4Cu(OH) 2 0.6Ni(OH) 2 /CdS photocatalyst shows hydrogen production of ~20 mmol h−1 g−1. • Cocatalysts Cu/Ni hydroxides are transformed into their metallic states during photoreaction. • The mechanism of hydrogen production from water splitting over Cu/Ni(hydroxides)-CdS is proposed. [ABSTRACT FROM AUTHOR]

[Display omitted] • Transition metal nitrides (TMNs) have gained substantial interest to catalyse water splitting reaction. • Iron and nickel based TMNs are considered as ideal electrocatalysts because of the abundance, low cost, and high catalytic activity. • Single phase TMNs have unsatisfactory performance due to inadequate M−H/M−OH bond strength. • Recent developments pertaining to Fe and Ni-based TMNs are presented for electrochemical water splitting. Transition metal nitrides (TMNs) have gained substantial interest to generate hydrogen from direct dissociation of water via catalytic strategy. Due to the unique noble metal like structure, high electric conductivity, corrosion resistance, broad pH stability and probable structural modifications TMNs are gauged as efficient hydrogen evolution reaction (HER), oxygen evolution reaction (OER) and overall water splitting (OWS) electrocatalysts. Iron and nickel based TMNs are considered as ideal electrocatalysts because of the abundance, low cost and high catalytic activity as compared to the expensive benchmark catalysts. However, the single phase TMNs have unsatisfactory performance due to inadequate M−H/M−OH bond strength. Most researchers have focused in designing advanced heterostructures by doping other metals, metallic compounds, and conductive substrates to improve catalytic performance due to the tailored electronic structure to modify M−H/M−OH bond strength, boost electrochemical stability and synergistic effects. In this review, we highlight the recent developments pertaining to Fe and Ni-based TMNs from the stance of advanced nanoarchitecture electrocatalysts for electrochemical water splitting. The key challenges and future perspectives confronting expansion of water splitting catalysts are critiqued. [ABSTRACT FROM AUTHOR]

An efficient electrochemical urea oxidation reaction (UOR) could be used in energy production technology. Metallic nickel nano-particles (Ni NPs) are incorporated in cobalt hydroxide layered material to form Ni/Co(OH) 2. The synthesized material is utilized as an electrocatalyst in UOR. It has been revealed that the incorporation of Ni NPs into cobalt hydroxide significantly enhances their electrocatalytic activity toward UOR. Ni/Co(OH) 2 catalyzes UOR at a very low anodic potential of 1.15 V vs RHE with a peak current density of 14.2 mAcm−2 and Tafel slope of 75 mVdec−1. The current work is a step ahead towards use of transition metal hydroxide (TMH) as support in the electrocatalytic oxidation applications especially UOR. [ABSTRACT FROM AUTHOR]