Amorphous nanomaterials with long-range disordered structures could possess distinct properties and promising applications, especially in catalysis, as compared with their conventional crystalline counterparts. It is imperative to achieve the controlled preparation of amorphous noble metal-based nanomaterials for the exploration of their phase-dependent applications. Here, we report a facile wet-chemical reduction strategy to synthesize various amorphous multimetallic Pd-based nanomaterials, including PdRu, PdRh, and PdRuRh. The phase-dependent catalytic performances of distinct Pd-based nanomaterials towards diverse catalytic applications have been demonstrated. Specifically, the usage of PdRu nanocatalysts with amorphous and crystalline face-centered cubic (fcc) phases can efficiently switch the ring-opening route of styrene oxide to obtain different products with high selectivity through alcoholysis reaction and hydrogenation reaction, respectively. Moreover, when used as an electrocatalyst for hydrogen evolution reaction (HER), the synthesized amorphous PdRh nanocatalyst exhibits low overpotential and high turnover frequency values, outperforming its crystalline fcc counterpart and most of the reported Pd-based HER electrocatalysts.

The plastic pollution has become one of the top environmental concerns. Substantial effort has been devoted into recycling waste plastic materials in a facile and economical way. In this work, we have successfully recycled a common type of plastic waste, i.e., polystyrene (PS), into value-added functional materials through a cost-effective and facile dip-coating method. The resulted mixture of waste PS and SiO₂, referred to as PS/SiO₂, coated textile material is superhydrophobic and superoleophilic, showing an excellent resistance towards corrosive solutions (acid, alkaline, and saline), high temperature treatment, and mechanical abrasion. As a proof-of-concept application, the PS/SiO₂-coated textile is used to selectively separate oil/water mixtures through either absorption or filtration method. It also exhibits a surface self-cleaning property, which may be used as fabrics for dust-preventing cloths. Our work offers a new strategy to treat the waste for preparation of novel low-cost superhydrophobic materials for various applications.

As one of the important materials, nanocrystalline Au (n-Au) has gained numerous interests in recent decades owing to its unique properties and promising applications. However, most of the current n-Au thin films are supported on substrates, limiting the study on their mechanical properties and applications. Therefore, it is urgently desired to develop a new strategy to prepare n-Au materials with superior mechanical strength and hardness. Here, a hard n-Au material with an average grain size of ~ 40 nm is prepared by cold-forging of the unique Au nanoribbons (NRBs) with unconventional 4H phase under high pressure. Systematic characterizations reveal the phase transformation from 4H to face-centered cubic (fcc) phase during the cold compression. Impressively, the compressive yield strength and Vickers hardness (H_V) of the prepared n-Au material reach ~ 140.2 MPa and ~ 1.0 GPa, which are 4.2 and 2.2 times of the microcrystalline Au foil, respectively. This work demonstrates that the combination of high-pressure cold-forging and the in-situ 4H-to-fcc phase transformation can effectively inhibit the grain growth in the obtained n-Au materials, leading to the formation of novel hard n-Au materials. Our strategy opens up a new avenue for the preparation of nanocrystalline metals with superior mechanical property.

In the past decades, metal-containing nanomaterials have attracted increasing interests owing to their intriguing physicochemical properties and various promising applications. Recent research has revealed that the phase of metal-containing nanomaterials could significantly affect their properties and functions. In particular, nanomaterials with amorphous phase, which possess long-range disordered atomic arrangements, and the amorphous/crystalline heterophase nanostructures comprised of both amorphous and crystalline phases, have exhibited superior performance in various applications, e.g., catalysis and energy storage. In this review, a brief overview of the recent progress on the wet-chemical synthesis and applications of amorphous and amorphous/crystalline heterophase metal-containing nanomaterials has been provided. Subsequently, on the basis of different categories of metal-containing nanomaterials, including metals, metal alloys, and metal compounds, their synthetic routes and promising applications will be highlighted. Finally, current challenges and some personal perspectives in this emerging research field will be proposed.

Crystal phase can greatly affect the physicochemical properties and applications of nanomaterials. However, it still remains a great challenge to synthesize nanostructures with the same composition and morphology but different phases in order to explore the phase-dependent properties and applications. Herein, we report the crystal phase-controlled synthesis of PtCu alloy shells on 4H Au nanoribbons (NRBs), referred to as 4H-Au NRBs, to form the 4H-Au@PtCu core-shell NRBs. By tuning the thickness of PtCu, 4H-PtCu and face-centered cubic (fcc) phase PtCu (fcc-PtCu) alloy shells are successfully grown on the 4H-Au NRB cores. This thickness-dependent phase-controlled growth strategy can also be used to grow PtCo alloys with 4H or fcc phase on 4H-Au NRBs. Significantly, when used as electrocatalysts for the ethanol oxidation reaction (EOR) in alkaline media, the 4H-Au@4H-PtCu NRBs show much better EOR performance than the 4H-Au@fcc-PtCu NRBs, and both of them possess superior performance compared to the commercial Pt black. Our study provides a strategy on phase-controlled synthesis of nanomaterials used for crystal phase-dependent applications.