Zizai Ma

Highly active carbon supported ternary PdSnPtx (x = 0.1–0.7) catalysts for ethanol electro-oxidation in alkaline and acid media

A series of trimetallic PdSnPtx (x=0.1-0.7)/C catalysts with varied Pt content have been synthesized by co-reduction method using NaBH4 as a reducing agent. These catalysts were characterized using X-ray diffraction (XRD), transmission electron microscopy (TEM), high resolution transmission electron microscopy (HRTEM), energy dispersive X-ray spectroscopy (EDX), X-ray photoelectron spectroscopy (XPS), cyclic voltammetry (CV) and chronoamperometry (CA). The electrochemical results show that, after adding a minor amount of Pt dopant, the resultant PdSnPtx/C demonstrated more superior catalytic performance toward ethanol oxidation as compared with that of mono-/bi-metallic Pd/C or PdSn/C in alkaline solution and the PdSnPt0.2/C with optimal molar ratio reached the best. In acid solution, the PdSnPt0.2/C also depicted a superior catalytic activity relative to the commercial Pt/C catalyst. The possible enhanced synergistic effect between Pd, Sn/Sn(O) and Pt in an alloyed state should be responsible for the as-revealed superior ethanol electro-oxidation performance based upon the beneficial electronic effect and bi-functional mechanism. It implies the trimetallic PdSnPt0.2/C with a low Pt content has a promising prospect as anodic electrocatalyst in fields of alkali- and acid-type direct ethanol fuel cells.

Well-dispersed palladium nanoparticles on nickel- phosphorus nanosheets as efficient three-dimensional platform for superior catalytic glucose electro-oxidation and non-enzymatic sensing

In this work, we report a novel well-dispersed palladium nanoparticles (PdNPs)/nickel-phosphorus nanosheets (Ni-P NSs) synthesized by combination of red phosphorous phosphorization and simple electrodeposition technique. The obtained PdNPs/Ni-P nanosheets framework with large electrochemical active surface would not only exhibit much superior electrocatalytic activity (180.5±3.07mAcm-2) toward glucose oxidation reaction, but also represent a wide linear range (2μM-4.65mM) and high sensitive detection of glucose (242.5±3.28μAmM-1cm-2) as non-enzymatic glucose sensor. The three- dimensional (3D) PdNPs/Ni-P nanosheets have a promising prospect as a novel kind of highly active nanocatalyst and non-enzymatic electrochemical sensor.

Self-Supported Ternary Ni–S–Se Nanorod Arrays as Highly Active Electrocatalyst for Hydrogen Generation in Both Acidic and Basic Media: Experimental Investigation and DFT Calculation

In this study, a novel three-dimensional self-supported ternary NiS-Ni9S8-NiSe nanorod (NR) array cathode has been successfully in situ constructed by a two-step hydrothermal route. When applied to hydrogen evolution, the synthesized NiS-Ni9S8-NiSe-NR electrode demonstrates optimized electrocatalytic activity and long-term durability, only requiring overpotentials as low as 120 and 112 mV to drive 10 mA cm-2 for hydrogen evolution reaction in 0.5 M H2SO4 and 1.0 M KOH, respectively. Density functional theory calculation reveals that after Se doping Se 3d orbitals are bonded to Ni 3d orbitals and S p orbitals near Fermi level, attesting a significant electron transfer between nickel and selenium atoms. The success of enhancing the electrocatalytic performance via introducing the Se dopant holds great promise for the potential optimization of other transition-metal compounds in highly efficient electrochemical water splitting for large-scale hydrogen production.

FACILE SYNTHESIS OF Pt-/Pd-MODIFIED NiTi ELECTRODE WITH SUPERIOR ELECTRO-CATALYTIC ACTIVITIES TOWARD METHANOL, ETHANOL AND ETHYLENE GLYCOL OXIDATION

Surface functional modification of NiTi electrode with noble Pt and Pd metal has been successfully carried out by simple and cost effective electro-spark deposition technique (ESD). Thin-film X-ray diffraction (TF-XRD), scanning electron microscopy (SEM), energy dispersive X-ray analysis (EDX) and cyclic voltammetry (CV) have been carried out in order to investigate the structure, morphology, chemical composition and electrochemical behavior of the modified electrode surface. The modified Pt/NiTi and Pd/NiTi electrode surface exhibit a circular splash pattern with a tiny amount of Pt (∼5.30 at.% Pt) and Pd (∼5.71 at.% Pd) existence. The electrochemical results demonstrate that the Pt/NiTi and Pd/NiTi electrode possess an improved electro-catalytic activities toward methanol (MeOH), ethanol (EtOH) and ethylene glycol (EG) oxidation in alkaline media in comparison with the bare NiTi electrode. In acidic environments, the Pt/NiTi electrode exhibits even much better catalytic activities than the pure Pt sheet electrode due to the bi-functional mechanism. In the same way, the electro-catalytic activity of the modified Pd/NiTi electrode is also slightly larger than that of the pure Pd sheet electrode in alkaline environment. The electro-spark surface modification approach is rapid and environmentally-benign, being attractive to widen the application of traditional surface modification technique in the field of material surface/interface design and functionalization.