An Approach towards Synthesis of Nanoarchitectured LiNi1/3Co1/3Mn1/3O2 Cathode Material for Lithium Ion Batteries

To explore advanced cathode materials for lithium ion batteries(LIBs),a nanoarchitectured LiNi_(1/3)Co_(1/3)Mn_(1/3)O_(2)(LNCM)material is developed using a modified carbonate coprecipitation method in combination with a vacuum distillation-crystallisation process.Compared with the LNCM materials produced by a traditional carbonate copre-cipitation method,the prepared LNCM material synthesized through this modified method reveals a better hexago-nal layered structure,smaller particle sizes(ca.110.5 nm),and higher specific surface areas.Because of its unique structural characteristics,the as-prepared LNCM material demonstrates excellent electrochemical properties in-cluding high rate capability and good cycleability when it is utilized as a cathode in the lithium ion battery(LIB).

Oxidative Molecular Layer Deposition Tailoring Eco-Mimetic Nanoarchitecture to Manipulate Electromagnetic Attenuation and Self-Powered Energy Conversion

Advanced electromagnetic devices,as the pillars of the intelligent age,are setting off a grand transformation,redefining the structure of society to present pluralism and diversity.However,the bombardment of electromagnetic radiation on society is also increasingly serious along with the growing popularity of"Big Data".Herein,drawing wisdom and inspiration from nature,an eco-mimetic nanoarchitecture is constructed for the first time,highly integrating the advantages of multiple components and structures to exhibit excellent electromagnetic response.Its electromagnetic properties and internal energy conversion can be flexibly regulated by tailoring microstructure with oxidative molecular layer deposition(oMLD),providing a new cognition to frequency-selective microwave absorption.The optimal reflection loss reaches≈−58 dB,and the absorption frequency can be shifted from high frequency to low frequency by increasing the number of oMLD cycles.Meanwhile,a novel electromagnetic absorption surface is designed to enable ultra-wideband absorption,covering almost the entire K and Ka bands.More importantly,an ingenious self-powered device is constructed using the eco-mimetic nanoarchitecture,which can convert electromagnetic radiation into electric energy for recycling.This work offers a new insight into electromagnetic protection and waste energy recycling,presenting a broad application prospect in radar stealth,information communication,aerospace engineering,etc.

Recent progress on MOF/MXene nanoarchitectures:A new era in coordination chemistry for energy storage and conversion

The development of urbanization and industrialization leads to rapid depletion of fossil fuels.Therefore,the production of fuel from renewable resources is highly desired.Electrotechnical energy conversion and storage is a benign technique with reliable output and is eco-friendly.Developing an exceptional electrochemical catalyst with tunable properties like a huge specific surface area,porous channels,and abundant active sites is critical points.Recently,Metal-organic frameworks(MOFs)and two-dimensional(2D)transition-metal carbides/nitrides(MXenes)have been extensively investigated in the field of electrochemical energy conversion and storage.However,advances in the research on MOFs are hampered by their limited structural stability and conventionally low electrical conductivity,whereas the practical electrochemical performance of MXenes is impeded by their low porosity,inadequate redox sites,and agglomeration.Consequently,researchers have been designing MOF/MXene nanoarchitectures to overcome the limitations in electrochemical energy conversion and storage.This review explores the recent advances in MOF/MXene nanoarchitectures design strategies,tailoring their properties based on the morphologies(0D,1D,2D,and 3D),and broadening their future opportunities in electrochemical energy storage(batteries,supercapacitors)and catalytic energy conversion(HER,OER,and ORR).The intercalation of MOF in between the MXene layers in the nanoarchitectures functions synergistically to address the issues associated with bare MXene and MOF in the electrochemical energy storage and conversion.This review gives a clear emphasis on the general aspects of MOF/MXene nanoarchitectures,and the future research perspectives,challenges of MOF/MXene design strategies and electrochemical applications are highlighted.

Hierarchical Interconnected NiMoN with Large Specific Surface Area and High Mechanical Strength for Efficient and Stable Alkaline Water/Seawater Hydrogen Evolution

NiMo-based nanostructures are among the most active hydrogen evolution reaction(HER)catalysts under an alkaline environment due to their strong water dissociation ability.However,these nanostructures are vulnerable to the destructive effects of H_(2) production,especially at industry-standard current densities.Therefore,developing a strategy to improve their mechanical strength while maintaining or even further increasing the activity of these nanocatalysts is of great interest to both the research and industrial communities.Here,a hierarchical interconnected NiMoN(HW-NiMoN-2h)with a nanorod-nanowire morphology was synthesized based on a rational combination of hydrothermal and water bath processes.HW-NiMoN-2h is found to exhibit excellent HER activity due to the accomodation of abundant active sites on its hierarchical morphology,in which nanowires con-nect free-standing nanorods,concurrently strengthening its structural stability to withstand H_(2) production at 1 A cm^(−2).Seawater is an attractive feedstock for water electrolysis since H_(2) generation and water desalination can be addressed simultaneously in a single process.The HER performance of HW-NiMoN-2h in alkaline seawater suggests that the presence of Na+ions interferes with the reation kinetics,thus lowering its activity slightly.However,benefiting from its hierarchical and interconnected characteristics,HW-NiMoN-2h is found to deliver outstanding HER activity of 1 A cm^(−2) at 130 mV overpotential and to exhibit excellent stability at 1 A cm^(−2) over 70 h in 1 M KOH seawater.

Wet-Chemical Synthesis and Applications of Semiconductor Nanomaterial-Based Epitaxial Heterostructures

Semiconductor nanomaterial-based epitaxial heterostructures with precisely controlled compositions and morphologies are of great importance for various applications in optoelectronics,thermoelectrics,and catalysis.Until now,various kinds of epitaxial heterostructures have been constructed.In this minireview,we will first introduce the synthesis of semiconductor nanomaterial-based epitaxial heterostructures by wet-chemical methods.Various architectures based on different kinds of seeds or templates are illustrated,and their growth mechanisms are discussed in detail.Then,the applications of epitaxial heterostructures in optoelectronics,catalysis,and thermoelectrics are described.Finally,we provide some challenges and personal perspectives for the future research directions of semiconductor nanomaterial-based epitaxial heterostructures.

Phosphine-free synthesis of FeTe2 nanoparticles and self-assembly into tree-like nanoarchitectures

Manipulating the self-assembly of transition metal telluride nanocrystals(NCs) creates opportunities for exploring new properties and device applications. Iron ditelluride(FeTe2) has recently emerged as a new class of magnetic semiconductor with three-dimensional(3D) magnetic ordering and narrow band gap structure, yet the self-assembly of FeTe2 NCs has not been achieved. Herein, the tree-like FeTe2 nanoarchitectures with orthorhombic crystal structure have been successfully synthesized by hot-injection solvent thermal approach using phosphine-free Te precursor. The morphology, size, and crystal structure have been investigated using transmission electron microscopy(TEM), high-resolution TEM(HRTEM),and powder x-ray diffraction(XRD). We study the formation process of tree-like FeTe2 NCs according to trace the change of the sample morphology with the reaction time. It was found that the FeTe2 nanoparticles show oriented aggregation and self-assembly behavior with the increase of reaction time, which is attributed to size-dependent magnetism properties of the samples. The magnetic interaction is thought to be the driving force of nanoparticle self-organization.

Subtle Variations in Surface Properties of Black Silicon Surfaces Influence the Degree of Bactericidal Efficiency

One of the major challenges faced by the biomedical industry is the development of robust synthetic surfaces that can resist bacterial colonization. Much inspiration has been drawn recently from naturally occurring mechano-bactericidal surfaces such as the wings of cicada(Psaltoda claripennis) and dragonfly(Diplacodes bipunctata) species in fabricating their synthetic analogs. However,the bactericidal activity of nanostructured surfaces is observed in a particular range of parameters reflecting the geometry of nanostructures and surface wettability. Here,several of the nanometer-scale characteristics of black silicon(bSi) surfaces including the density and height of the nanopillars that have the potential to influence the bactericidal efficiency of these nanostructured surfaces have been investigated. The results provide important evidence that minor variations in the nanoarchitecture of substrata can substantially alter their performance as bactericidal surfaces.

Yolk-shell nanoarchitecture for stabilizing a Ce_(2)S_(3)anode

Rare-earth sulfides are of research interest for lithium-ion batteries(LIBs)due to their abundant lithium intercalation sites and low redox voltage.However,their electrochemical performances are not satisfactory because of poor conductivity and volume change upon electrochemical cycling.Herein,nanoarchitectures ofγ-Ce_(2)S_(3)encapsulated in a hollow mesoporous carbon nanosphere(Ce_(2)S_(3)@HMCS)are fabricated using the self-template strategy combined with the in-sphere sulfuration method and tested as an LIB anode.The void space between the Ce_(2)S_(3)core and the outer layer of the carbon nanosphere has been properly designed and modulated to achieve excellent electrochemical performance in terms of electronic conductivity,reversibility,and rate capability.The reversible capacity of Ce_(2)S_(3)@HMCS is 2.6 times that of the pure Ce_(2)S_(3)anode,which can gradually increase and maintain a capacity of 282 mAh·g^(−1)at a current density of 1 A·g^(-1),and a high Coulombic efficiency(~100%)can be achieved even after 1000 cycles.This good performance is attributed to the unique yolk-shell nanostructure with a highly crystallized and stable Ce3S2 core and volume expansion buffer space upon lithiation/delithiation.Ex situ X-ray diffraction and nuclear magnetic resonance results indicate that the lithiation of Ce_(2)S_(3)@HMCS is an intercalation process.This study represents an important advancement in precise structural design with in-sphere sulfuration and sheds light on a potential direction for highperformance lithium storage.

Three-dimensional sea urchin-like MnCo_(2)O_(4)nanoarchitectures on Ni foam towards high-performance asymmetric supercapacitors

To construct supercapacitors(SCs)with high-efficient electrochemical properties,the morphology and structure of applied electrode materials are the key factors.Herein,three-dimensional(3D)sea urchin-like MnCo_(2)O_(4)nanoarchitectures grown on Ni foam(NF)were successfully synthesized via a simple solvothermal method and subsequent annealing treatment.Electrochemical tests revealed that the area specific capacitances of the MnCo_(2)O_(4)electrode and the corresponding assembled asymmetric device can achieve 1634 and 522 mF·cm^(-2),respectively.When the power density of the assembled asymmetric supercapacitor(ASC)is 2.25 mW·cm^(-2),the maximum energy density can reach 0.163 mW·h·cm^(-2).After 5500 cycles of long-term stability test,the capacity retention rate maintains 91.7%.The excellent electrochemical performance can be mainly ascribed to the unique nanostructure of the material,which provides a great quantity of electroactive sites for Faraday redox reactions as well as accelerates the process of the ions/electrons transport.This work provides a certain reference value for the preparation of MnCo_(2)O_(4)electrode with novel structure and excellent electrochemical performance for SCs.

Biomass-based biomimetic-oriented Janus nanoarchitecture for efficient heavy-metal enrichment and interfacial solar water sanitation

Interfacial solar steam generation(ISSG),involving the use of solar energy to evaporate water at the water-to-vapor interface,has presented prospects for the desalination and purification of water due to high energy conversion efficiency and low-cost freshwater generation.Herein,inspired by the aligned nanostructure of plants for efficiently transporting nutrient ions,we optimally design and construct a biomass-based Janus architecture evaporator with an oriented nanostructure for ISSG,using the ice template method,followed by biomimetic mineralization with the resource-abundant and low-cost biomass of the carboxymethyl cellulose and sodium alginate as the raw materials.Taking advantage of the oriented nanostructure allowing efficient transportation of water and coordination capacity of sodium alginate for effective enrichment of heavy-metal ions,the biomass-based Janus architecture shows much lower thermal conductivity and an ultrahigh steam regeneration rate of 2.3 kg m−2 h−1,considerably surpassing those of previously reported oriented biomass-based evaporators.Moreover,the biomass precursor materials are used for this Janus evaporator,guaranteeing minimum impact on the water ecology and environment during the regeneration process of clean drinking water.This study presents an efficient,green,and sustainable pathway for ISSG to effectively achieve heavy-metal-free drinking water.

Ultrathin nanobelts-assembled Chinese knot-like 3D TiO2 for fast and stable lithium storage

Nanostructured TiO2 has applications in solar cells, photocatalysts, and fast- charging, safe lithium ion batteries （LIBs）. To meet the demand of high-capacity and high-rate LIBs with TiO2-based anodes, it is important to fine-tune the nanoarchitecture using a well-controlled synthesis approach. Herein, we report a new approach that involves epitaxial growth combined with topotactic conversion to synthesize a unique type of three-dimensional （3D） TiO2 nano- architecture that is assembled by well-oriented ultrathin nanobelts. The whole nanoarchitecture displays a 3D Chinese knot-like morphology; the core consists of robust perpendicular interwoven nanobelts and the shell is made of extended nanobelts. The nanobelts oriented in three perpendicular [001]A directions facilitate Li＋ penetration and diffusion. Abundant anatase/TiO2-B interfaces provide a large amount of interfacial pseudocapacitance. A high and stable capacity of 130 mA.h.g-1 was obtained after 3,000 cycles at 10 A·g-1 （50 C）, and the high-rate property of our material was greater than that of many recently reported high-rate TiO2 anodes. Our result provides, not only a novel synthesis strategy, but also a new type of 3D anatase TiO2 anode that may be useful in developing long-lasting and fast-charging batteries.

Ga(X)N/Si nanoarchitecture:An emerging semiconductor platform for sunlight-powered water splitting toward hydrogen

Sunlight-powered water splitting presents a promising strategy for converting intermittent and virtually unlimited solar energy into energy-dense and storable green hydrogen.Since the pioneering discovery by Honda and Fujishima,considerable efforts have been made in this research area.Among various materials developed,Ga(X)N/Si(X=In,Ge,Mg,etc.)nanoarchitecture has emerged as a disruptive semiconductor platform to split water toward hydrogen by sunlight.This paper introduces the characteristics,properties,and growth/synthesis/fabrication methods of Ga(X)N/Si nanoarchitecture,primarily focusing on explaining the suitability as an ideal platform for sunlight-powered water splitting toward green hydrogen fuel.In addition,it exclusively summarizes the recent progress and development of Ga(X)N/Si nanoarchitecture for photocatalytic and photoelectrochemical water splitting.Moreover,it describes the challenges and prospects of artificial photosynthesis integrated device and system using Ga(X)N/Si nanoarchitectures for solar water splitting toward hydrogen.