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Today, the development of new self-supporting electrode materials with high porosity and excellent degradation properties is of great importance for the removal of dye pollutants. Herein, this work synthesized nanoporous nickel@nickel oxide (np-Ni@NiO) electrode containing an amorphous alloy in the middle interlayer. The nanoporous structure endowed the electrode with more active sites and facilitated the ion/electron transport. The electrochemical active surface area was about 185.5 cm2. The electrochemical degradation of rhodamine B (RhB) using a np-Ni@NiO electrode was systematically investigated. The effects of technology paraments (NaCl concentration, the applied potential and pH) on electro-catalytic degradation were explored. An RhB removal rate of 99.68% was achieved in 30 s at optimized conditions, which was attributed to the unique bicontinuous ligament/pore structure and more active sites on the surface, as well as lower charge transfer resistance. In addition, the degradation mechanism of RhB in electrochemical oxidation was proposed, according to active species capture tests and EPR measurements. [ABSTRACT FROM AUTHOR]

Designing a novel photocatalytic composite for the efficient degradation of organic dyes remains a serious challenge. Herein, the multi-layered Co3O4@NP-CuO photocatalyst with unique features, i.e., the self-supporting, hierarchical porous network as well as the construction of heterojunction between Co3O4 and CuO, are synthesized by dealloying-electrodeposition and subsequent thermal treatment techniques. It is found that the interwoven ultrathin Co3O4 nanopetals evenly grow on the nanoporous CuO network (Co3O4@NP-CuO). The three-dimensional (3D) hierarchical porous structure for the catalyst provides more surface area to act as active sites and facilitates the absorption of visible light in the photodegradation reaction. Compared with the commercial CuO and Co3O4 powders, the newly designed Co3O4@NP-CuO composite exhibits superior photodegradation performance for RhB. The enhanced performance is mainly due to the construction of heterojunction of Co3O4/CuO, greatly promoting the efficient carrier separation for photocatalysis. Furthermore, the possible photocatalytic mechanism is analyzed in detail. This work provides a promising strategy for the fabrication of a new controllable heterojunction to improve photocatalytic activity. [ABSTRACT FROM AUTHOR]

A free-standing Cu 2 O/CuO@nanoporous copper/bulk metallic glass (Cu 2 O/CuO@NPC/BMG) composite rod with a multimodal hierarchical porous structure has been successfully prepared by a facile two-step synthesis strategy consisting of dealloying and anodizing. The NPC/BMG composite is first fabricated by dealloying of Cu 50 Zr 45 Al 5 BMG rod. Then the ultrafine Cu 2 O/CuO nanosheet arrays are synthesized by anodizing of the NPC/BMG rod followed by heat treatment. The as-obtained Cu 2 O/CuO@NPC/BMG composite possesses a multimodal hierarchical porous structure comprising interconnected pores ranging from micro, meso to macro sizes. It is worth pointing out that there are several "barren lands" without nanosheets grown on the surface of the composite. Further analyses indicate that the microstructures of substrate materials not only dominate the sizes of Cu 2 O/CuO sheets, but also influence the nucleation and growth of Cu 2 O/CuO sheets. Meanwhile, the possible formation mechanism of the Cu 2 O/CuO nanosheets is proposed. Accordingly, the Cu 2 O/CuO@NPC/BMG composite shows remarkably high photocatalytic degradation performance and excellent cycling stability for RhB due to the multimodal hierarchical porous structure, ultrafine Cu 2 O/CuO nanosheets in the entire NPC and the integration design strategy. Unlabelled Image • Anodizing is employed to design a free-standing Cu 2 O/CuO@NPC/BMG composite. • The composite exhibits a multimodal hierarchical porous structure. • Coexisting Cu+ and Cu2+ leads to a synergistic effect in improving properties. • The composite demonstrates high photocatalytic degradation performance for RhB. [ABSTRACT FROM AUTHOR]

By virtue of the high theoretical capacity of Si, Si-related materials have been developed as promising anode candidates for high-energy-density batteries. During repeated charge/discharge cycling, however, severe volumetric variation induces the pulverization and peeling of active components, causing rapid capacity decay and even development stagnation in high-capacity batteries. In this study, the Si/Fe2O3-anchored rGO framework was prepared by introducing ball milling into a melt spinning and dealloying process. As the Li-ion battery (LIB) anode, it presents a high reversible capacity of 1744.5 mAh g−1 at 200 mA g−1 after 200 cycles and 889.4 mAh g−1 at 5 A g−1 after 500 cycles. The outstanding electrochemical performance is due to the three-dimensional cross-linked porous framework with a high specific surface area, which is helpful to the transmission of ions and electrons. Moreover, with the cooperation of rGO, the volume expansion of Si is effectively alleviated, thus improving cycling stability. The work provides insights for the design and preparation of Si-based materials for high-performance LIB applications. [ABSTRACT FROM AUTHOR]

To improve glucose electrocatalytic performance, one efficient manner is to develop a novel Cu-Ag bimetallic composite with fertile porosity and unique architecture. Herein, the self-supported electrode with CuxO/Ag2O (x = 1, 2) nanowires grown in-situ on a nanoporous Cu-Ag network (CuxO/Ag2O@NP-CuAg) has been successfully designed by a facile two-step approach. The integrated hierarchical porous structure, the tip-converged CuxO/Ag2O nanowires combined with the interconnected porous conductive substrate, are favorable to provide more reactive sites and improve ions or electrons transportation. Compared with monometallic Cu2O nanowires integrated with nanoporous Cu matrix (Cu2O@NP-Cu), the bimetallic CuxO/Ag2O@NP-CuAg composites exhibit the enhanced electrocatalytic performance for glucose. Moreover, the higher sensitivity of ~1.49 mA mM−1 cm−2 in conjunction with a wider linear range of 17 mM for the CuxO/Ag2O@NP-CuAg electrode anodized for 10 min are attributed to the synergistic effect of porous structure and bimetallic CuxO/Ag2O nanowires. Particularly, the integrated CuxO/Ag2O@NP-CuAg composites possess good flexibility, which has been reported for the first time. Accordingly, the CuxO/Ag2O@NP-CuAg with excellent glucose electrocatalytic performance and good flexibility is promising to further develop as a candidate electrode material of glucose sensors. [ABSTRACT FROM AUTHOR]

• Self-supporting porous Cu 9 S 5 @NPC photoanodes are obtained via a new strategy. • Photoanodes present superior photoelectrocatalytic degradation performance. • This work constructs the heterojunction between Cu 9 S 5 and NPC. • The possible photoelectrocatalytic mechanism of Cu 9 S 5 @NPC is investigated. Self-supporting Cu 9 S 5 @nanoporous copper (Cu 9 S 5 @NPC) heterogenous photoelectrodes with controllable morphologies and hierarchical porous structures are synthesized through dealloying and anodization strategy. 3D Cu 9 S 5 nanostructures (nanosheets or nanorods) grown in-situ on the surface of nanoporous copper (NPC) network are affected by the concentration ratio of Na 2 S and NaOH in the mixed aqueous solutions. It is found that lower Na 2 S concentration induces the formation of nanosheets. Attributing to the fertile porous channels, self-supporting structures as well as synergistic effect of Cu 9 S 5 and NPC, the Cu 9 S 5 @NPC photoelectrodes possess outstanding photoelectrocatalytic (PEC) performance for the degradation of Methylene blue (MB) dye at the bias of 0.5 V under visible irradiation. Moreover, the possible PEC mechanism is further investigated. [ABSTRACT FROM AUTHOR]

• The np-Ni@NiO/MG sandwich electrode without corrosion cracks is fabricated. • The flexibility of the electrode is remarkably improved by eliminating cracks. • The electrodes show excellent electrochemical performance at bending deformation. • The flexible supercapacitor delivers a high energy density of 20.5 mWh cm−3. It is a great challenge to fabricate the cracks-free nanoporous metals (NPMs) for flexible supercapacitor electrodes, since the formation of corrosion cracks caused by dealloying easily results in the fracture of NPMs. This work successfully achieves the sandwich uniform nanoporous Ni@NiO core@shell electrodes containing metallic glass interlayer (np-Ni@NiO/MG) with enhanced flexibility and high electrochemical performance by controlling corrosion rates of the Ni 40 Zr 60 MG precursors. To clarify the origin for high fragility of NPMs and improve its flexibility for wearable energy storage devices, the influence of the concentration of HF etching solution on the morphology, flexibility as well as mechanical integrity of the dealloyed Ni 40 Zr 60 MG are investigated. It is amazingly discovered that controlling the corrosion rates of the dealloying precursors is effective in eliminating the corrosion cracks, and markedly improving the flexibility of the obtained np-Ni@NiO/MG electrodes. Moreover, as for flexible energy storage electrode, the electrochemical performance of the np-Ni@NiO/MG sandwich electrodes subjected to various bending deformation are further examined. Furthermore, a flexible all-solid-state supercapacitor (FAS) device is assembled and two FASs in series can easily light a green LED, demonstrating a highly application prospect as a wearable energy storage device. [ABSTRACT FROM AUTHOR]

• Cu x O/Ag 2 O@NP-CuAg composites are fabricated by dealloying and anodizing strategy. • The self-supported flexible electrode shows hierarchical porous structure. • The electrode shows prominent electrocatalytic activity for glucose detection. • The glucose electrocatalytic mechanism of the composites is proposed. At present, it is of great significance to develop novel free-standing electrode materials with high porosity and excellent glucose electrocatalytic performance for glucose detection. Herein, we synthesize two types of self-supported electrodes with Cu x O or Cu x O/Ag 2 O (x = 1, 2) nanowires grown on the nanoporous substrate via dealloying of Cu 50-x Zr 50 Ag x (x = 0 and 7.5 at%) metallic glasses, followed by anodizing and calcination. The effects of adding Ag element into Cu 50 Zr 50 MG precursor on the morphology and electrochemical performance of electrodes are systematically investigated. Compared with cluster-like copper monometallic oxide nanowire on nanoporous Cu (Cu x O@NPC, x = 1, 2) electrode, the in-situ grown copper-silver bimetallic oxide nanowire on nanoporous Cu-Ag (Cu x O/Ag 2 O@NP-CuAg) electrode with tip convergence and hierarchical porous structure possesses better electrooxidation performance for glucose. The newly developed Cu x O/Ag 2 O@NP-CuAg electrode exhibits a high sensitivity of 1.31 mA mM−1 cm−2 and wide linear range up to 15 mM, outstanding anti-interference ability and stability. The enhanced electrocatalytic performance is mainly due to the synergistic effect of Cu and Ag elements as well as unique structural characteristics. Meanwhile, the possible glucose electrocatalytic mechanism of Cu x O/Ag 2 O@NP-CuAg electrode is proposed. The as-developed materials with good glucose sensing performance and flexibility will be highly promising in wearable glucose sensors. [ABSTRACT FROM AUTHOR]

• Dual-network nanoporous NiFe 2 O 4 /NiO composite is prepared by dealloying strategy. • The high capacity is guaranteed by the synergistic effect of NiFe 2 O 4 and NiO. • Huge volume change is accommodated by the unique porous structure. • The composite shows enhanced electrochemical performance as a Li-ion battery anode. The electrochemical properties of traditional graphite anodes cannot meet the current market requirements, which restrict the commercial applications of lithium-ion batteries (LIBs). Herein, we report a facile one-step dealloying strategy to fabricate dual-network nanoporous NiFe 2 O 4 /NiO composites. The composite presents excellent electrochemical performance, delivering a high reversible capacity of 1618 mAh g−1 at 200 mA g−1 for 100 cycles followed at 500 mA g−1 for 250 cycles. Even at 1000 mA g−1, a specific capacity of 416 mAh g−1 can be retained after 2000 cycles. The good electrochemical performance ascribes to the synergistic effect of two kinds of active materials (NiFe 2 O 4 and NiO) and the unique dual-network porous structure, in which the plenty of pores can accommodate the volume change during the charge/discharge cycling while a mass of mesopores on the skeletons shorten the diffusion distances of ions and electrons. The employed strategy opens a door for the novel structural design of dealloyed anode materials, which may facilitate the further development of the dealloying technique for various application fields. [ABSTRACT FROM AUTHOR]

Nickelous oxide (NiO) is a promising anode for Lithium ion (Li-ion) batteries. However it suffers from rapid degradation due to large volume change upon cycling. In this work, a novel strategy to accommodate the volume change of NiO-based anodes during charge/discharge cycling through employment of the advantages of bimodal porous Nickel–Silicon (Ni–Si) network and Nickelous oxide@Nickel (NiO@Ni) shell@core structure is proposed. The designed bimodal nanoporous NiO@Ni–Si network exhibits a stable Li-ion storage property with an extremely high reversible capacity of 1656.9 mAh g−1 at 200 mA g−1 after 300 repeated cycles and 1387.1 mAh g−1 at 500 mA g−1 after 1000 cycles. It also shows a good rate performance, delivering about 400 mAh g−1 even at a current density of 2000 mA g−1. Post-cycling microscopy and impedance studies reveals the minor changes in the electrode structure that, in turn, results in an extremely low capacity degradation rate of 0.03%/cycle. The employed strategy enriches the structural design idea of dealloying products, which may further promote the development of the dealloying field and can be applied in future to prepare various types of porous shell@core anodes for Li-ion battery applications. Image 1 • Bimodal nanoporous NiO@Ni–Si network is prepared by dealloying method. • The material contains bimodal porous Ni–Si network and NiO@Ni shell@core structure. • Huge volume change is accommodated by bimodal porous shell@core network. • The composite shows stable storage performance as an anode for Li-ion battery. [ABSTRACT FROM AUTHOR]

• Nanoporous bimetal Cu-Ag (NP-CuAg) is firstly used as the anodizing substrate. • Cu x O nanowires modified by Ag nanoparticles uniformly grow on NP-CuAg substrate. • The Ag/Cu x O@NP-CuAg composite exhibits excellent antibacterial activity. • The work offers an idea to form multicomponent material with various structures. Nano-sized bimetal, bimetallic oxides and their composites have aroused widespread research interests because of their multifunctional performances. The development of their novel structures and synthesis techniques is urgently needed. Herein, we fabricated a novel Ag nanoparticles modified Cu x O (x = 1, 2) nanowires on nanoporous copper-silver network (Ag/Cu x O@NP-CuAg) with hierarchical porous structure through dealloying and anodizing process. Nanoporous CuAg bimetal network (NP-CuAg), prepared by dealloying of Cu 40 Zr 50 Ag 10 metallic glass (MG) ribbon, was used as the anodizing substrate to provide bimetal sources for the first time. Then Ag nanoparticles modified Cu x O (x = 1, 2) nanowires were synthesized on NP-CuAg network by anodizing and calcination. Due to the unique structure and the synergistic effect of Cu and Ag elements, the as-obtained composite presents good antibacterial activity and a wide application prospect as a multifunctional material. [ABSTRACT FROM AUTHOR]