A highly sensitive and stable electrochemical sensor for simultaneous detection towards ascorbic acid, dopamine, and uric acid based on the hierarchical nanoporous PtTi alloy.

In current work highly sensitive and stable electrochemical sensor for simultaneous detection of ascorbic acid (AA), dopamine (DA), and uric acid (UA) is constructed based on the hierarchical nanoporous (HNP) PtTi alloy. The HNP-PtTi alloy is simply fabricated by two-step dealloying process, characterized by the bimodal ligament/pore size distributions and interconnected hollow channels. The HNP structure with the advantages of large surface area, excellent structure stability, and rich pore channels is used for facilitating the electron conductivity and the mass transfer. Combined with the dual effects of the bimodal nanoporous architecture and the excellent electrocatalytic activity of PtTi alloy, the constructed sensor exhibits high electrochemical sensing activity with wide linear responses from 0.2 to 1mM, 0.004 to 0.5mM, and 0.1 to 1mM for simultaneous detection of AA, DA, and UA, respectively. In addition, HNP-PtTi alloy also shows long-term sensing stability towards the AA, DA, and UA detection and behaves as a good anti-interference towards NaCl, KCl, FeCl3, CuCl2, AlCl3, glucose, and H2O2. The HNP-PtTi alloy manifests intriguing application potential as the candidate for the application of the electrochemical sensor for simultaneous detection of AA, DA, and UA.

A nanoporous palladium-nickel alloy with high sensing performance towards hydrogen peroxide and glucose.

The nanoporous (NP) PdNi alloy is easily fabricated by one-step mild dealloying of PdNiAl precursor alloy in NaOH solution. Characterized by the nanoporous network architecture with the ligament size as small as 5nm, NP-PdNi alloy exhibits higher electrocatalytic activity towards the oxidation of H2O2 and glucose compared with NP-Pd and Pd/C catalysts. The electrochemical sensor constructed based on NP-PdNi alloy shows high sensing performance towards H2O2 and glucose with a wide linear range, long-term stability, and fast amperometric response. Moreover, NP-PdNi alloy exhibits high resistance towards Cl(-) poisoning as well as good anti-interference towards ascorbic acid, urci acid, and dopamine. This work provides a simple and green route to construct highly active and sensitive electrochemical sensor for detecting H2O2 and glucose.

Porous Co3O4/CuO composite assembled from nanosheets as high-performance anodes for lithium-ion batteries.

Upon dealloying a carefully designed CoCuAl ternary alloy in NaOH solution at room temperature, a Co3 O4 /CuO nanocomposite with an interconnected porous microstructure assembled by a secondary structure of nanosheets was successfully fabricated. By using the dealloying strategy, the target metals directly grew to form uniform bimetallic oxide nanocomposites. Owing to the unique hierarchical structure and the synergistic effect of both active electrode materials, the Co3 O4 /CuO nanocomposite exhibits much enhanced electrochemical performance with higher capacities and better cycling stability compared to anodes of pure Co3 O4 . Moreover, it performs excellently in terms of cycle reversibility, Coulombic efficiency, and rate capability, at both low or high current rates. With the advantages of unique performance and ease of preparation, the as-made Co3 O4 /CuO nanocomposite demonstrates promising application potential as an advanced anode material for lithium-ion batteries.

Si/Ag composite with bimodal micro-nano porous structure as a high-performance anode for Li-ion batteries.

A one-step dealloying method is employed to conveniently fabricate a bimodal porous (BP) Si/Ag composite in high throughput under mild conditions. Upon dealloying the carefully designed SiAgAl ternary alloy in HCl solution at room temperature, the obtained Si/Ag composite has a uniform bicontinuous porous structure in three dimensions with micro-nano bimodal pore size distribution. Compared with the traditional preparation methods for porous Si and Si-based composites, this dealloying route is easily operated and environmentally benign. More importantly, it is convenient to realize the controllable components and uniform distribution of Si and Ag in the product. Owing to the rich porosity of the unique BP structure and the incorporation of highly conductive Ag, the as-made Si/Ag composite possesses the improved conductivity and alleviated volume changes of the Si network during repeated charging and discharging. As expected, the BP Si/Ag anode exhibits high capacity, excellent cycling reversibility, long cycling life and good rate capability for lithium storage. When the current rate is up to 1 A g(-1), BP Si/Ag can deliver a stable reversible capacity above 1000 mA h g(-1), and exhibits a capacity retention of up to 89.2% against the highest capacity after 200 cycles. With the advantages of unique performance and easy preparation, the BP Si/Ag composite holds great application potential as an advanced anode material for Li-ion batteries.

The nanoporous PdCr alloy as a nonenzymatic electrochemical sensor for hydrogen peroxide and glucose.

The nanoporous (NP) PdCr alloy is easily fabricated through one step mild dealloying a PdCrAl source alloy in NaOH solution. Electron microscopy demonstrates that dealloying a PdCrAl alloy generates a bicontinuous spongy morphology with a narrow ligament size of ∼5 nm. The as-made NP-PdCr alloy exhibits high sensing performance toward H2O2, such as a wide linear range from 0.1 to 1.9 mM, fast amperometric response, and a low detection limit of 3.1 µM. In particular, the NP-PdCr alloy has distinct sensing durability with almost no activity loss upon continuous H2O2 detection for two weeks. In addition, this nanostructure exhibits high activity for glucose sensing in a wide linear range from 1 to 38 mM, long-term stability, and it is also highly resistant toward poisoning by Cl-. Moreover, NP-PdCr shows good anti-interference toward ascorbic acid, uric acid, and dopamine after coating excess Nafion solution.

Facile fabrication of nanoporous PdFe alloy for nonenzymatic electrochemical sensing of hydrogen peroxide and glucose.

Nanoporous (NP) PdFe alloy is easily fabricated through one step mild dealloying of PdFeAl ternary source alloy in NaOH solution. Electron microscopy characterization demonstrates that selectively dissolving Al from PdFeAl alloy generates three-dimensional bicontinuous nanospongy architecture with the typical ligament size around 5 nm. Electrochemical measurements show that the NP-PdFe alloy exhibits the superior electrocatalytic activity and durability towards hydrogen peroxide (H2O2) detection compared with NP-Pd and commercial Pd/C catalysts. In addition, NP-PdFe performs high sensing performance towards H2O2 in a wide linear range from 0.5 to 6 mM with a low detection limit of 2.1 µM. This nanoporous structure also can sensitively detect glucose over a wide concentration range (1-32 mM) with a low detection limit of 1.6 µM and high resistance against chloride ions. Along with these attractive features, the as-made NP-PdFe alloy also has a good anti-interference towards ascorbic acid, uric acid, and dopamine.