Oxygen Passivation Stabilizes Sub-2-nm Aluminum Nanosheets

Multimodal biosensing systems based on metal nanoparticles

Biosensors are currently among the most commonly used devices for analysing biomarkers and play an important role in environmental detection, food safety, and disease diagnosis. Researchers have developed multimodal biosensors instead of single-modal biosensors to meet increasing sensitivity, accuracy, and stability requirements. Metal nanoparticles (MNPs) are beneficial for preparing core probes for multimodal biosensors because of their excellent physical and chemical properties, such as easy regulation and modification, and because they can integrate diverse sensing strategies. This review mainly summarizes the excellent physicochemical properties of MNPs applied as biosensing probes and the principles of commonly used MNP-based multimodal sensing strategies. Recent applications and possible improvements of multimodal biosensors based on MNPs are also described, among which on-site inspection and sensitive detection are particularly important. The current challenges and prospects for multimodal biosensors based on MNPs may provide readers with a new perspective on this field.

A semi-fluid multi-functional binder for a high-performance silicon anode of lithium-ion batteries

Currently, a variety of binders are developed to inhibit the rapid capacity fading of Si. The Si anodes are mainly enhanced by the chemical bonding effect on the surface of conventional solid-state binders. However, with a huge volume change of silicon, solid binders are easily deactivated. Herein, a semi-fluid binder termed GPC is designed based on a viscoelastic crosslinking network with abundant active sites and self-healing performance. The backbone of the binder network is in situ synthesized using guar gum (GG), polyacrylic acid (PAA), and citric acid (CA). Serving as the flexible joints and the plasticizer of the network, CA small molecules remarkably improve the viscoelasticity of the binder to tolerate the volume change of Si via rearranging particles in the network during cycling. Moreover, CA can form a layer of surface coating on Si to stabilize the SEI for long-term electrochemical performance. As a result, the Si@GPC electrode shows excellent cycling stability and exhibits a superb capacity of 1292 mA h g^-1 after 1000 cycles at 2 A g^-1. This work illustrates the advantages and prospects of designing semi-fluid binders for high-performance batteries.

Hard-templated engineering of versatile 2D amorphous metal oxide nanosheets

Two-dimensional (2D) nanomaterials have received ever-increasing attention and in-depth exploration in multifarious fields on account of their superior mass transfer ability and abundant catalytic-active sites. Especially, the amorphous 2D nanomaterials feature unique properties distinct from atomic crystalline materials. However, the synthesis of high-quality and large-sized amorphous 2D nanomaterials encounters a big challenge. Here, a general and facile synthetic strategy for a series of 2D amorphous metal and nonmetallic oxides nanosheets, including SiO₂, AlOOH, ZrO₂and TiO₂nanosheets, is reported. The versatile 2D amorphous nanomaterials are fabricatedviamanipulating the surface energy of relevant metal alkoxide precursors with liquid feature and controlling the related synthesis parameters to form solid 2D amorphous nanosheets byin situhydrolysis and condensation of precursors. Density functional theory (DFT) calculations reveal the molecular adsorption mechanism of wetting process of precursor infiltrated on solid NaCl substrate, which attributes to the strong interaction between Na-O atom pairs from NaCl and metal alkoxides respectively. Furthermore, taking the 2D Fe-ZrO₂nanomaterials as the catalyst, the excellent catalytic performance for Rhodamine B (RhB) degradation illustrates that these 2D nanomaterials prepared by this method have the characteristics of easy functionalization. This work provides an efficient strategy for nanomaterials functionalization during 2D nanosheets synthetic process and further being applied in catalysis-related field and beyond.