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Hierarchical nitrogen-doped carbon encapsulated hollow ZnSe/CoSe2 (ZnSe/CoSe2@N-C) nanospheres are fabricated by a convenient solvothermal and selenization approach, followed by a carbonization process. The as-obtained ZnSe/CoSe2@N-C possesses a multilevel nanoscale architecture composed of a thin carbon shell with a size of around 12 nm and hollow selenide nanoparticles as the core with tiny rough grains and rich voids as the subunits. The robust carbon protective shell and synergistic effect between double metal ions boost the electron and ion transportation as well as promote effective extraction and insertion of lithium ions. Hollow ZnSe/CoSe2@N-C spheres show high reversible capacity with 1153 mA h g-1 remaining over 100 cycles at 100 mA g-1. In particular, the hollow ZnSe/CoSe2@N-C spheres show an outstanding cycling stability at a high rate of 2000 mA g-1 with the reversible capacity of up to 966 mA h g-1 remaining after 500 cycles. As an advanced anode, ZnSe/CoSe2@N-C composite shows remarkable cycling stability and exceptional rate capability in the field of energy storage technologies.

Hierarchical mulberry-like iron-cobalt sulfide (Fe3S4/Co9S8) nanoparticles were conveniently fabricated through etching the FeCoAl alloy in mild conditions followed by one-step facile sulfurization process. The as-made sulfide nanoparticles are composed of interconnected tiny particles and numerous pore channels as the building subunits. Coupling with the hierarchical nanostructure and the synergistic effects between the dual sulfides, the Fe3S4/Co9S8 composite demonstrated the outstanding lithium storage performances in terms of superior reversible capacity, good rate performance, and exceptional cycling stability. The specific capacity of 945 mAh g−1 could be reserved over Fe3S4/Co9S8 composite at 100 mA g−1 after 100 cycles. More importantly, upon long-term cycles for 1500 loops under the high rate of 2000 mA g−1, the specific capacity of the as-made sulfide still retained as high as 519 mAh g−1. Fe3S4/Co9S8 composite presents prospective application potential in the field of energy storage technologies.

Hierarchical macroporous Si/Sn composites are fabricated via one facile and green dealloying process by etching SiSnAl alloy precursors. The as-made Si/Sn composites consist of three dimensional hierarchical macroporous Si network and bimodal pore channels as the built units with Sn nanoparticles uniformly distributed on the porous surface. Owing to its hierarchical porous architecture and incorporation of Sn nanoparticles, the Si85Sn15 sample delivers much higher specific capacity, superior cycling stability, and better rate capability compared with Si80Sn20 and pure Si anodes. The Si85Sn15 composite presents a steady capacity about 1600 mA h g−1 at 200 mA g−1 in the period of 70 cycles. Even the current rates are set up to 3000 and 4000 mA g−1, Si85Sn15 can still exhibit the high capacities of ∼800 and ∼620 mA h g−1, respectively. In particular, the lithium storage performances of Si85Sn15 composite are superior to those of most other reported Si/Sn or Si/Sn-based anodes. The as-made Si/Sn composite shows the promising application prospect as an alternative anode candidate for lithium-ion batteries with the excellent performances and easy preparation.

Carbon encapsulated porous Sn/Sn4P3 (Sn/Sn4P3@C) composite is conveniently prepared by one-step electrochemical dealloying of Sn80P20 alloy in mild conditions followed by growing one carbon layer. Controllable dealloying of the Sn80P20 alloy results in the formation of bicontinuous spongy Sn4P3 nanostructure with a part of residued metallic Sn atoms embedded in the porous skeleton. A uniform carbon layer is deposited on the nanoporous Sn/Sn4P3 to prevent the nanostructure’s pulverizing and agglomerating during lithium ion insertion/extraction. Upon double conductivity modification from metallic Sn matrix and carbon layer, the as-made composite displays superior lithium-storage performances with much higher specific capacity as well as better cycling stability compared with pure porous Sn4P3. It offers a specific capacity of 837 mA h g−1 after 100 cycles at a rate of 100 mA g−1. Even after 700 cycles at the higher rate of 1000 mA g−1, the specific capacity still maintains as high as 589 mA h g−1. The Sn/Sn4P3@C material possesses promising application potential as an alternative anode in the lithium storage fields.

Nanoporous Ge/Cu3Ge composite is fabricated simply through selective dealloying of GeCuAl precursor alloy in dilute alkaline solution. The as-made Ge/Cu3Ge is characterized by three dimensional (3D) bicontinuous network nanostructure which comprises of substantial nanoscale pore voids and ligaments. Owing to the 3D porous architecture and the introduction of well-conductive Cu3Ge, the lithium storage performances of Ge are dramatically enhanced in terms of higher cycling stability and superior rate performance. Nanoporous Ge/Cu3Ge anode delivers steady capacities above 1000 mA h g−1 upon cycling for 70 loops at 400 mA g−1. In particular, after 300 cycles at the high rate of 3200 mA g−1 the capacity retention for Ge/Cu3Ge is able to reach a maximum of 99.3%. On the contrary, the pure nanoporous Ge encounters severe capacity decay. In view of the outstanding energy storage performances and easy preparation, nanoporous Ge/Cu3Ge exhibits great application potential as an advanced anode in lithium storage related technologies.

Hollow NiCoSex (H-NiCoSex) nanospheres encapsulated with carbon shell were prepared via one-step easy solvothermal method followed by the carbon coating process. H-NiCoSex@C has large interior void with the uniform dimension around 350 nm and the thickness of carbon shell around 20–30 nm. Coupling with the large interior void as well as robust protective carbon shell, H-NiCoSex@C can retain the reversible capacity of 805.6 mAh·g−1 after 100 cycles at 200 mA·g−1. In particular, H-NiCoSex@C delivers large reversible capacity of 1532.2 mAh·g−1 upon cycling for 1000 loops at 1000 mA·g−1 with the capacity retention as high as 128.2% upon long period of activation. Even at the high rate of 3000 mA·g−1, its specific capacity still retains up to 659.3 mAh·g−1. The superior lithium storage performances for H-NiCoSex@C profit from its robust hollow core-shell structure as well as enhanced electrical conductivity and ion transport.

A superior NADH sensing platform was constructed based on porous PtAg nanoshells supported on reduced graphene oxide (PtAg/rGO) in the absence of any enzymes and redox mediators. The PtAg/rGO composite was prepared via one-step reduction combined with galvanic replacement reaction. The as-made PtAg/rGO assembles multiple structural advantages of coherent conductive matrix, rich electroactive sites, and high specific surface area, accompanied by the unique alloying effect. The PtAg/rGO possesses adequate active reaction sites and fluent electron transport pathway towards the electrocatalytic NADH oxidation, thus presenting significantly increased oxidation current and negative shift of 330 mV in applied potential relative to the bare GCE. By virtues of the outstanding electrocatalytic activity, PtAg/rGO exhibits effective amperometric detection of NADH at 0.15 V within a wide linear concentration range of 2–2378 μM, a high sensitivity of 92.62 μA mM−1 cm−2, low detection limit of 0.2 μM, and long-term detection over 2500 s. Moreover, the as-constructed biosensors can achieve accurate NADH detection in human serum samples, indicating its promising application feasibility in fundamental and clinic research.

Nanoporous Si@TiO2 composites with the unique core-shell architecture are conveniently fabricated through one-step selective dealloying of SiTiAl ternary alloy under mild conditions. The as-prepared composites consist of bimodal Si network skeleton as the core and interconnected TiO2 nanosponge layer as the shell uniformly distribute on the Si surface to form the porous core-shelled structure. The nanoporous TiO2 as the outer protective layer not only reduce the violent volume change of electrode materials for stable cycling performance but also shorten the diffusion distance of Li+ for high rate capacities. The inner bimodal porous Si possesses an open bicontinuous network structure that can provide the enough empty space and robust backbone to relax the volume variation of composite and guarantee the sufficient electrode-electrolyte contact area. As a result, the optimized nanoporous Si@TiO2 composite delivers the reversible capacity of 1338.1 and 1174.4 mA h g−1 at the current densities of 200 and 1000 mA g−1 after continuous tests for 120 and 100 cycles, respectively. With the advantages of easy preparation, unique architecture, and high lithium storage performances, the porous core-shelled Si@TiO2 composites demonstrate the promising application potential as an anode material for LIBs.

Carbon particles modified macroporous Si/Ni composite (MP-Si/Ni/C) is easily obtained via a facile fabrication of porous Si/Ni precursor by dealloying SiNiAl alloy followed by a surface growth of carbon nanoparticles. MP-Si/Ni/C composite possesses the multiply conductivity modification that are built through mixing Ni dispersoid and growing one layer of carbon particles. Coupled with the structural advantages of interconnected network backbone, rich voids, and the coated carbon particles, MP-Si/Ni/C exhibits dramatically enhanced lithium storage performances with excellent reversible capacity, enhanced rate performance, as well as outstanding cycling stability compared with pure MP-Si and MP-Si/Ni. Especially, the reversible capacity remains up to 1113.1 and 708.8 mA h g−1 at the current densities of 200 and 1000 mA g−1 after 120 cycles, respectively. Besides, it shows excellent rate capability even when continuously cycled at high current density of 3000 mA g−1. With the advantages of unique structure, excellent performances, and facile preparation, the as-made MP-Si/Ni/C composite shows promising application potential as an alternative anode for lithium ion batteries.

The accurate detection of the superoxide anion (O2•−) has vital academic and medical diagnostic significance due to its important dual roles in biological functioning. In this work, hollow porous PtAg nanospheres (PtAg HPNSs) were fabricated by a facile hydrothermal method followed by a dealloying procedure. The as-made PtAg nanospheres possessed hollow interiors and porous shells composed of interconnected ligaments and pores with the typical size around 4 nm. Benefitting from the unique hollow nanoporous architecture and the specific alloying effect, the PtAg HPNSs showed high electrocatalytic activity towards superoxide anions. The constructed biosensor based on PtAg HPNSs presented a fast and ultrasensitive response in a wide range of 0.8–1080 nM with much higher sensitivity of 4.5 × 10−2 μA cm−2 nM−1 and low detection limit of 0.2 nM (S/N = 3). Moreover, the novel biosensors can achieve electrochemical detection for O2•− released from living cells, exhibiting outstanding real time detection capability in cell environment. The facile controllable fabrication and unique sensing performance for PtAg HPNSs offers potential practical applications in developing highly sensitive and stable biosensor towards superoxide anion.

Multimodal nanoporous PtCu flowers (np-PtCu) were prepared via a two-step dealloying strategy under mild conditions. The np-PtCu alloy possesses an interconnected flower-like network skeleton with multiscale pore distribution. This material was placed on a glassy carbon electrode where it shows outstanding detection performance towards hydrogen peroxide and glucose in near-neutral pH solutions. It can be attributed to the specific structure in terms of interconnected nanoscaled ligaments, rich pore openings and a synergistic alloying effect. Figures of merit for detection H2O2 assay include (a) a working voltage of 0.7 V (vs. the reversible hydrogen electrode); (b) a wide linear response range (from 0.01 to 1.7 mM), and (c) a low detection limit (0.1 μM). The respective data for the glucose assay are (a) 0.4 V, (b) 0.01–2.0 mM, and (c) 0.1 μM. The method is not interfered in the presence of common concentrations of dopamine, acetaminophen and ascorbic acid.

Multimodal porous Si/Zn composites with controllable components and large porosity are conveniently fabricated through one-step selective dealloying of SiZnAl precursor alloys under green and safe conditions. The as-made Si/Zn composites possess open interconnected three-dimensional (3D) network structure with multiscale pore distributions from scores of nanometer to micro scale. Nanoporous (NP) Si/Zn composites exhibit superior reversible capacity, high rate performance, as well as outstanding cycling stability in virtues of 3D interlinked nanoscale scaffold, massive pore openings, and highly conductive Zn dispersoid. The lithium storage performances of as-made anodes follow the order of Si80Zn20 > Si85Zn15 > Si75Zn25 > Si. The optimal NP-Si80Zn20 delivers the high reversible capacity of 901.8 mAh g−1 at 1000 mA g−1 after continuous cycles as long as 1000 loops. Moreover, the full cell assembling with LiFePO4 cathode and NP-Si80Zn20 anode exhibits a large initial coulombic efficiency of 88.9% and respectable cycling stability. With the merits of excellent energy storage performances as well as green and simple preparation, NP-Si/Zn composite as the promising candidate presents attractive application value for lithium ion batteries.

Hierarchical nanoporous (HNP) NiCoO2/Ni composite is directly fabricated by one-step dealloying of NiCoAl ternary alloy in mild alkaline solution. HNP-NiCoO2/Ni composite is composed of three dimensional interlinking ligament backbone and open hollow channels with rich mesopores and macropores penetrating through. HNP-NiCoO2/Ni possesses preferable structure advantages to construct sensing platform in term of large surface area, robust multimodal porous architecture, as well the incorporation of well conductive Ni. As is expected, exceptional electrochemical sensing performances are achieved over HNP-NiCoO2/Ni with high sensitivity, superior selectivity, and long term durability toward DA assay even without any activation pretreatment. Especially, HNP-NiCoO2/Ni exhibits a wide linear detection range from 1 to 800 μM with a rapid response in ~2.8 s and a detection limit as low as 0.12 μM. Furthermore, HNP-NiCoO2/Ni also shows a good anti-interference toward DA detection in the presence of AC, glucose, H2O2, Cl−, K+, and Na+. Along with the merits of simple preparation, low cost, and excellent electrocatalytic performances, the as-prepared HNP-NiCoO2/Ni presents promising application potential to construct highly sensitive electrochemical sensors for DA assay.

Macroporous (MP) Ge skeleton wrapped with TiO2 particles layer is straightforwardly fabricated via one-step etching of the GeTiAl precursor alloy under mild conditions. During the selective dissolution of Al from GeTiAl alloy, Ge atoms assemble to form three dimensional (3D) network nanostructure with rich porosity. Ti atoms undergo the natural oxidation and aggregation to form TiO2 particles layer distributed on the porous Ge surface. Combined with the 3D porous architecture and robust TiO2 layer, the as-prepared Ge@TiO2 shows unique lithium storage performances with superior cycling stability and rate capability. It delivers a reversible capacity of 963 mAh g−1 after 100 cycles at 400 mA g−1. Even after cycling for 300 loops at the high rate of 3200 mA g−1, the specific capacity still remains as high as 717 mAh g−1. MP Ge@TiO2 material presents promising application potential as an alternative anode in the fields of lithium storage technologies.

A support-free hierarchical nanoporous (NP) Cu@Cu2O composite is easily fabricated by dealloying Cu5Al95 alloy in dilute NaOH solution. This bulk material has a support-free spongy structure composed of three-dimensional interconnected ligaments and open pore channels with multimodal pore size distributions. The NP-Cu@Cu2O catalyst exhibits high activity, good chemoselectivity, and excellent recyclability toward one-pot transfer hydrogenation reactions of diverse nitroarenes to anilines. NP-Cu@Cu2O can effectively activate ammonia borane under mild conditions and complete the transfer hydrogenation reactions with high yields within a short time period of 5 min Cu2O formed at the nanoporous surface is proposed to be the actual active site causing this advanced performance. The main reaction intermediates were successfully separated and characterized, and a plausible condensation mechanism has been proposed for nitro reduction.

Nanoporous (NP) PtCo and PtNi alloy ribbons with predetermined bimetallic compositions are easily fabricated by one step of mild dealloying, which are characterized by uniform three-dimensional bicontinuous network architecture with the ligament size as small as 3 nm. Compared with E-TEK Pt/C catalyst, the as-made NP-PtCo(Ni) alloys exhibit superior specific activity with the lower peak potential and enhanced CO-tolerance toward methanol electrooxidation. More importantly, these nanomaterials also show much higher structure stability with little loss of the electrochemical surface area of Pt upon 5000 potential cycles in acid solution. X-ray photoelectron spectroscopy and DFT calculations revealed that alloying with Co or Ni modifies the electronic structure of Pt with the downshift of Pt d-band center, thus resulting in the improved methanol oxidation activity and decreased CO poisoning.

Nanoporous platinum was fabricated by a simple dealloying method. Electron microscope characterizations show that selectively etching Al from PtAl alloy precursors in alkali or acid solution can both easily prepare three-dimensional bicontinuous network nanostructures of Pt. The resulted nanostructure exhibited much enhanced catalytic performance towards methanol electrooxidation compared with commercial Pt/C catalyst. More importantly, CO stripping and potentiostatic tests demonstrated that nanoporous Pt has much higher long-term catalytic stability and CO resistance than the Pt/C catalyst. Copyright © 2011 VBRI press.