https://onlinelibrary.wiley.com/doi/pdf/10.1002/adfm.202003261

Bifunctional Heterostructured Transition Metal Phosphides for Efficient Electrochemical Water Splitting

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3D MXene Architectures for Efficient Energy Storage and Conversion

Metal-based nanoparticles have gained tremendous popularity because of their interesting physical, biological, optical, and magnetic properties. These nanoparticles can be synthesized using a variety of different physical, chemical, and biological techniques. The biological means are largely preferred as it provides an environmentally benign, green, and cost-effective route for the biosynthesis of nanoparticles. These bioresources can act as a scaffold, thereby playing the role of reducing as well as capping agents in the biosynthesis of nanoparticles. Medicinal plants tend to have a complex phytochemical constituent such as alcohols, phenols, terpenes, alkaloids, saponins, and proteins, while microbes have key enzymes which can act as reducing as well as stabilizing agent for NP synthesis. However, the mechanism of biosynthesis is still highly debatable. Herein, the present review is directed to give an updated comprehensive overview towards the mechanistic aspects in the biosynthesis of nanoparticles via plants and microbes. Various biosynthetic pathways of secondary metabolites in plants and key enzyme production in microbes have been discussed in detail, along with the underlying mechanisms for biogenic NP synthesis.

Role of plant phytochemicals and microbial enzymes in biosynthesis of metallic nanoparticles.

Porous MXenes: Synthesis, structures, and applications

The oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) are crucial reactions in energy conversion and storage systems including fuel cells, metal–air batteries, and electrolyzers. Developing low-cost, highefficiency, and durable non-noble bifunctional oxygen electrocatalysts is the key to the commercialization of these devices. Here, based on an in-depth understanding of ORR/OER reaction mechanisms, recent advances in the development of non-noble electrocatalysts for ORR/OER are reviewed. In particular, rational design for enhancing the activity and stability and scalable synthesis toward the large-scale production of bifunctional electrocatalysts are highlighted. Prospects and future challenges in the field of oxygen electrocatalysis are presented.

Recent Advances in Non‐Noble Bifunctional Oxygen Electrocatalysts toward Large‐Scale Production

Nanostructured metallic transition metal carbides, nitrides, phosphides, and borides for energy storage and conversion

Presented are the novel Ti3C2Tx MXene-based nanohybrid that decorated by pyrite nanodots on its surface (denoted as FeS2@MXene). The nanohybrid was obtained by the one-step sulfurization of self-assembled iron hydroxide@MXene precursor. When used for Li/Na-ion storage, the FeS2@MXene nanohybrid present excellent rate capabilities. Particularly, for Li-ion storage, an elevated reversible specific capacity of 762 mAh g–1 at 10 A g–1 after 1000 cycles was achieved. And for Na-ion storage, the FeS2@MXene nanohybrid also delivering a reversible specific capacity of 563 mAh g–1 after 100 cycles at a current density of 0.1 A g–1.

Porous MXene Frameworks Support Pyrite Nanodots toward High-Rate Pseudocapacitive Li/Na-Ion Storage

Plant polyphenols extracted from plants are one of the most abundant biomasses in nature, which are typical water soluble natural polymers. Herein, we reported a facile approach for the synthesis of platinum nanoparticle (PtNP) aqueous colloid by utilizing black wattle tannin (BWT, a typical plant polyphenol) as amphiphilic stabilizer. The phenolic hydroxyls of BWT provide the PtNPs with enough hydrophilicity, and their reduction ability could protect the PtNPs from deactivation caused by oxygen atmosphere. Additionally, the hydrophilic nature of BWT could efficiently promote the oxidation of alcohols in water, meanwhile, the hydrophobic and rigid backbones of plant polyphenols are able to suppress the PtNPs from aggregating, thus ensuring the high dispersion of the PtNPs during reactions. Under mild aerobic conditions, the as-prepared BWT-Pt colloid catalyst exhibited high activity in a series of biphasic oxidation of aromatic alcohols and aliphatic alcohols. As for the cycling stability, the BWT-Pt catalyst showed no obvious decrease during the 7 cycles, revealing superior cycling stability as compared with the counterparts using PVP or PEG as the stabilizer.

Water-soluble metal nanoparticles stabilized by plant polyphenols for improving the catalytic properties in oxidation of alcohols

High-throughput and high-accuracy nanofabrication methods are required for the ever-increasing demand for nanoelectronics, high-density data storage devices, nanophotonics, quantum computing, molecular circuitry, and scaffolds in bioengineering used for cell proliferation applications. The scanning probe lithography (SPL) nanofabrication technique is a critical nanofabrication method with great potential to evolve into a disruptive atomic-scale fabrication technology to meet these demands. Through this timely review, we aspire to provide an overview of the SPL fabrication mechanism and the state-the-art research in this area, and detail the applications and characteristics of this technique, including the effects of thermal aspects and chemical aspects, and the influence of electric and magnetic fields in governing the mechanics of the functionalized tip interacting with the substrate during SPL. Alongside this, the review also sheds light on comparing various fabrication capabilities, throughput, and attainable resolution. Finally, the paper alludes to the fact that a majority of the reported literature suggests that SPL has yet to achieve its full commercial potential and is currently largely a laboratory-based nanofabrication technique used for prototyping of nanostructures and nanodevices.

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Scanning Probe Lithography: State-of-the-Art and Future Perspectives

Here, a facile strategy is reported to efficiently hybridize metal nanoparticles (MNPs) with typical metal–organic frameworks (MOFs) of ZIF-8 (zeolitic imidazolate framework-8), which employs bovine serum albumin (BSA, a serum albumin protein derived from cows) as the amphiphilic stabilizer to increase the affinity of MNP toward MOFs. For instance, the as-synthesized PdNPs/ZIF-8 composites with diameter from 100 to 200 nm always maintain well-defined crystalline structure, and the PdNPs with small size of ∼2 nm are well-dispersed in the crystal of MOFs without serious aggregations due to the BSA stabilizer. In Suzuki cross-coupling reactions of aryl halide, the PdNPs/ZIF-8 as catalysts have exhibited high activity and satisfied reusability owing to the use of BSA stabilizer as well as the fixing of MOFs matrixes. In addition, the strategy also can be extended to synthesize other kinds of MNPs/MOFs hybrid composites with tunable particle size, which brings more opportunity for functional MOFs hybrid materials.

Hui Mao

Papers

Nanostructured metallic transition metal carbides, nitrides, phosphides, and borides for energy storage and conversion

Porous MXene Frameworks Support Pyrite Nanodots toward High-Rate Pseudocapacitive Li/Na-Ion Storage

Water-soluble metal nanoparticles stabilized by plant polyphenols for improving the catalytic properties in oxidation of alcohols

Scanning Probe Lithography: State-of-the-Art and Future Perspectives

Hybridization of Metal Nanoparticles with Metal–Organic Frameworks Using Protein as Amphiphilic Stabilizer