Catalytic decomposition of the hydrogen-rich hydrazine monohydrate (N2H4·H2O) represents a promising hydrogen storage/production technology. A rational design of advanced N2H4·H2O decomposition catalysts requires an overall consideration of intrinsic activity, number, and accessibility of active sites. We herein report the synthesis of a hierarchically nanostructured NiPt/N-doped carbon catalyst using a three-step method that can simultaneously address these issues. The chelation of metal precursors with polydopamine and thermolysis of the resulting complexes under reductive atmosphere resulted in a concurrent formation of N-doped carbon substrate and catalytically active NiPt alloy nanoparticles. Thanks to the usage of a silica nanosphere template and dopamine precursor, the N-doped carbon substrate possesses a hierarchical macroporous-mesoporous architecture. This, together with the uniform dispersion of tiny NiPt nanoparticles on the carbon substrate, offers opportunity for creating abundant and accessible active sites. Benefiting from these favorable attributes, the NiPt/N-doped carbon catalyst enables a complete and rapid hydrogen production from alkaline N2H4·H2O solution with a rate of 1602 h–1 at 50 °C, which outperforms most existing catalysts for N2H4·H2O decomposition.

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Synthesis of high-performance and nonprecious electrocatalysts for the hydrazine oxidation reaction (HzOR) is of vital importance for the development of direct hydrazine fuel cells (DHFCs) as a viable technology for portable or vehicular applications. Herein, we report a facile synthesis of a Ni foam (NF)-supported Ni−Co alloy catalyst with an urchin-like hierarchical nanostructure using a hydrothermal method combined with two-step calcination. The elaborate design and construction of such a self-supported electrocatalyst can simultaneously optimize the intrinsic activity, afford abundant accessible active sites, ensure good electrical conductivity, and facilitate the mass transfer of reactants and gaseous products. As a consequence, the Ni−Co/NF catalyst prepared under optimal conditions exhibited an exceptionally high activity of 1213 mA cm −2 at +0.30 V versus RHE, a low onset potential of −0.16 V versus RHE for the HzOR, good durability, and nearly 100% selectivity toward the HzOR following the four-electron pathway, outperforming the anode electrocatalysts of DHFCs hitherto reported.

to synthesize multicomponent and/or nanocomposite catalysts. Alloying Pt or Pd with 3d transition metals provides a straightforward way to alter the electronic structure and optimize the binding energies of adsorbates on the catalyst surface. [15][16][17][18][19][20][21][22][23][24][25] Creating synergistic catalysts via a combination of noble metals with oxophilic metal oxides/hydroxides proved a promising approach for improving the durability. [26][27][28][29][30][31][32][33][34] In a rational catalyst design, the OH adspecies on the surface of oxides/ hydroxides will facilitate the oxidative removal of carbonaceous intermediates adsorbed on the nearby Pd or Pt sites.Recently, the search for synergistic phases was further extended to transition metal non-oxides, like phosphides, [35][36][37][38] sulfides, [39] carbides, [40,41] and nitrides. [42][43][44][45][46] In comparison with the corresponding oxides, metal non-oxides exhibit much more abundant physicochemical properties owing to the complex and tunable interactions between metals and non-oxygen elements. For instance, in contrast to the insulator nature of most oxides, transition metal non-oxides span a remarkable range of conductivity properties, from insulator to semiconductor and to metal. Evidently, a rich variety of metal non-oxides with diverse properties offers increased degrees of freedom in the design of synergestic catalysts for the EOR. Among the materials of choice, transition metal nitrides (TMNs) are highly appealing but less well explored candidates. Theoretical studies found that TMNs (like Ni 3 N) typically show moderate binding energies of OH species, implying a compromise between the activation of OH and poisoning of the surface with reaction intermediates. [47] This, together with their high electrical conductivity and good chemical stability, clearly suggests the potential of TMN as a component phase in the synergistic catalysis of EOR. [48,49] Herein, we report the synthesis of a carbon fiber clothsupported nanocomposite catalyst consisting of highly dispersed Pd nanoparticles on the porous Co 3 N-Ni 3 N nanowires using a hydrothermal method followed by ammonization treatment and electrochemical deposition. Our study found that incorporation of Co 3 N-Ni 3 N of metallic nature could effectively improve the poisoning tolerance, while preserving good electrical conductivity of the electrocatalyst. Furthermore, the resulting hierarchical nanostructure of Co 3 N-Ni 3 N from the applied synthesis methods ensures the exposure of abundant active sites and a favorable reactant/product mass transfer kinetics. As a consequence, the Pd/Co 3 N-Ni 3 N/CFC catalyst Creating synergistic active sites via combination of palladium (Pd) or platinum (Pt) with oxophilic metal compounds has been extensively investigated as a promising approach for developing active and robust electrocatalysts toward the ethanol oxidation reaction (EOR). Among the metal compounds of choice, transition metal nitrides are highly appealing but less well explored candidates. H...

A glycosylation strategy based on click chemistry was employed to develop a naphthalimide-based Fe fluorescent probe with low cytotoxicity and good water-solubility. The selectivity and sensitivity to Fe of three synthesized naphthalimide-based fluorescent probes follows a Nap-PZ < Nap-OH < Nap-Glc trend, because Nap-PZ was modified with a good water-soluble group. The cytotoxicity follows a Nap-PZ > Nap-OH > Nap-Glc trend, because the exposed toxic group of Nap-PZ was shielded by a good biocompatible group. The detection limit toward Fe ion follows a Nap-PZ (7.40 × 10 M) > Nap-OH (2.73 × 10 M) > Nap-Glc (4.27 × 10 M) trend. Moreover, Nap-Glc could be used to detect Fe in living cells. The fluorescent "off-on" response of Nap-Glc towards Fe could be recognized by the naked eye, and the "off-on" fluorescent mechanism also was demonstrated by theoretical calculations. Therefore, Nap-Glc is a novel glucosyl naphthalimide fluorescent probe for environmental or biological detection of Fe with low cytotoxicity and good water-solubility.