Two-dimensional layered nanomaterials fortumor diagnosis and treatment

With the evolution of nanomedicine,the past decades witnessed diversified nanomaterials as marvelous antitumor tools ushering in a new era of tumor diagnosis and treatment.Among them,two-dimensional layered nano-material as an emerging class of nanomaterials has one dimension less than 100 nm,showing a high specific area and the thinnest sheet-like structure(Liu S,Pan X,Liu H.Twodimensional nanomaterials for photothermal therapy.Angew Chem Int Ed 2020;59:5890–900).The discovery of graphene drove the exploration of various new two-dimensional layered nanomaterials for tumor diagnosis and treatment including graphene-based nanomaterials,black phosphorus(BP),transition metal dichalcogenides(TMDs),layered double hydroxides(LDHs),and bismuth oxyhalides(BiOX,X=F,Cl,Br,I)(Ma H,Xue MQ.Recent advances in the photothermal applications of two-dimensional nanomaterial:photothermal therapy and beyond.J Mater Chem 2021;9:17569).On the one hand,they exhibit strong near-infrared(NIR)absorption and the capacity of optimizing corresponding properties by adjusting the crystal structure.On the other hand,they own unique strengths such as fantastic physicochemical properties(graphene-based nanomaterials),high loading capacity(BP),distinct phase-dependent optical properties(TMDs),a specific chemical response to the tumor microenvironment(LDHs),and large X-ray attenuation coefficient(BiOX).Herein,we briefly introduce three typical two-dimensional layered nanomaterials,their prospects and future research priorities in tumor diagnosis and treatment are concluded.

Layered photocatalytic nanomaterials for environmental applications

The increasing pollution and human demand for a cleaner environment have made achieving the environmental sustainability a current research focus.As a “green” technology,semiconductor photocatalysis is of great significance to the environmental purification.Benefiting from the unique anisotropic crystal structure and electronic properties,layered photocatalytic nanomaterials show great potential for efficient photocatalytic environmental treatment.This review comprehensively summarizes the recent progress on layered photocatalytic nanomaterials for oxidation or reduction of pollutants in water and air along with the basic understanding of related mechanisms and developments in this field.First,the existing diversified layered photocatalysts are classified,and their different synthesis and modification strategies are discussed in detail to provide a comprehensive view of the material design that affects their photocatalytic performance.Subsequently,the extensive applications of the above-mentioned layered photocatalytic nanomaterials in environmental fields are systematically summarized,including photooxidation of water and air pollutants,and photoreduction of heavy metal pollutants,NO_(3)^(-),BrO_(3)^(-) and CO_(2).Finally,based on the current research achievements in layered photocatalysts for environmental remediation,the future development direction and challenges are proposed.

New Conditions for Intercalation of Organic Compounds into Semiconductor Nanomaterial

The intercalation of organic guests, 2-methyl pyridine （2-picoline） and 3-methyl pyridine （3-picoline） into semiconductor layered nanomaterial （MnPS3） was investigated. New conditions were applied. New phases appeared and lattice expansions were 0.36 nm for 2-picoline intercalation and 0.728 nm for 3-picoline inter- calation. The XRD （X- ray diffraction） patterns exhibit sharp hkl reflections confirming that the material is highly crystalline. The interlayer gap （0.64 nm） of the host plays a role for the arrangement of the guest in the interlayer region. The crystal structure of the MnPS3 was indexed in the monoclinic system before inter- calation. After intercalation, the crystal system was indexed in the trigonal unit cell. The lattice parameters were obtained and c-axis value was related to the （001） reflections.

Recent Progress in Two-dimensional Nanomaterials Following Graphene for Improving Fire Safety of Polymer(Nano)composites

The high fire safety of polymer nanocomposites is being pursued by research institutions around the world.In addition to intrinsic flame retardancy strategy,the additive-type flame retardants have attracted increasing attention due to low commercial cost and easy fabrication craft.However,traditional additive-type flame retardants usually need high addition amount to achieve a desirable effect which causes many side-effects on the overall performance of polymer materials,such as deteriorated mechanical property and processability.At present two-dimensional(2D)nanomaterials have also been applied to reduce the fire hazards of polymer(nano)composites with the coupling of barrier function and catalysis as well as carbonization effect.Even though most research work mainly focus on graphene-based flame retardants,more emerging two-dimensional nanomaterials are taking away research attention,due to their complementary and unique properties,mainly including hexagonal boron nitride(h-BN),molybdenum disulfide(MoS2),metal organic frameworks(MOF),carbon nitride(CN),titanium carbide(MXene)and black phosphorene(BP).In this review,except for graphene,the flame retardant mechanism involving different layered nanomaterials are also reviewed.Meanwhile,the functionalization method and flame retardancy effect of different layered nanomaterials are emphatically discussed for offering an effective reference to solve the fire hazards of polymer materials.Moreover,this work objectively evaluates the practical significance of polymer/layered nanomaterials composites for industrial application.