Novel mechanical behavior of periodic structure with the pattern transformation

Abstract In periodic cellular structures, novel pattern transformations are triggered by a reversible elastic instability under the axial compression. Based on the deformation-triggered new pattern, periodic cellular structures can achieve special mechanical properties. In this paper, the designed architecture materials which include elastomer matrixes containing empty holes or filled holes with hydrogel material are modeled and simulated to investigate the mechanical property of the periodic materials. By analyzing the relationship between nominal stress and nominal strain of periodic material, and the corresponding deformed patterns, the influence of geometry and shapes of the holes on the mechanical property of architecture material is studied in more details. We hope this study can provide future perspectives for the deformation-triggered periodic structures.

Recent advances in photothermal effects for hydrogen evolution

Photothermal effect has been widely employed in the H2 evolution process at the advantage of using clean energy sources to produce another one of higher benefits.The solar-to-heat conversion have various forms and heat can facilitate reactions in a variety of dimensions.Hence,summarizing the sources and destinations of heat is important for constructing hydrogen production systems of higher efficiency.This view mainly focuses on the recent state-of-art progress of hydrogen evolution reaction(HER)based on photothermal effect.First,we introduce the main pathways of photothermal conversions applied in H2 evolution.Then,the functions of the photothermal effect are clearly summarized.Furthermore,we go beyond the catalytic reaction and introduce a method to improve the catalytic system by changing the catalytic bulk phase through thermal means.In the end,we sort out the challenges and outlook to offer some noble insights for this promising area.

Versatile oxidized variants derived from TMDs by various oxidation strategies and their applications

The physicochemical properties of transition metal dichalcogenides(TMDs)are highly related to their structures and usually stable in air.However,under certain conditions they could be transformed into different structures due to oxidation.Considering this,various materials with fascinating structures have been explored by oxidation strategies,which possess novel properties and great potential in various applications such as solar batteries,hydrogen evolution reaction(HER)catalysts,and field effect transistors(FET).In this review,we systematically summarize the atomic structures of TMD oxidized variants and the corresponding fabrication approaches.Utilizing various characterization methods,the chemical components of TMD oxidized variants are illustrated.Furthermore,we expound the promising applications of the oxidized variants.This review is expected to provide a new insight for preparing precise materials at the atomic level through corresponding oxidation strategies.

An Isolable Phosphinogermylyne as a Synthon of One-Coordinate GeⅠRadical

Reduction of chlorogermylene MsFluindtBu-GeCl 1 with potassium graphite(KC8)afforded putative germylyne radical MsFluindtBu-Ge 2 as confirmed by electron paramagnetic resonance(EPR)spectroscopy.However,it slowly decayed via C—H bond activation at the fluorenyl moiety to yield a bis(germylene)3 at room temperature.By using a Lewis base to stabilize the unoccupied p orbital at the GeⅠradical center,acyclic two-coordinate GeⅠradicals MsFluindtBu-Ge(IMe4)4(IMe4=1,3,4,5-tetramethyl-imidazolin-2-ylidene),MsFluindtBu-Ge(IiPr)5(IiPr=1,3-diisopropyl-4,5-dimethyl-imidazolin-2-ylidene),MsFluindtBu-Ge(PMe3)6 were isolated in crystalline forms.The unpaired electron in 4-6 mainly resides at the Ge 4p orbital as revealed by EPR spectroscopic studies and theoretical calculations.Interestingly,facile ligand exchange of PMe3 in 6 with IMe4 and IiPr was observed to afford 4 and 5,respectively.Moreover,phosphinogermylyne 6 reacted with PhEEPh(E=S,Se),4-tetrabutylphenylacetylene(Ar'CCH),[CpMo(CO)3]2 and nBu3SnH to furnish germylenes MsFluindtBu-GeEPh(E=S 7,Se 8),MsFluindtBu-GeCH=CHAr'9,a germylyne complex MsFluindtBu-Ge≡Mo(CO)2Cp 10 and a Ge(Ⅳ)compound MsFluindtBu-GeH2SnnBu311,respectively.The reactivity studies demonstrate that 6 can act as a synthon of one-coordinate germylyne radical attributing to labile coordination of trimethylphosphine.

Recent status and advanced progress of tip effect induced by micro-nanostructure

The unique structural features represented by micro-nanoneedle tip structure reflect wonderful physical and chemical properties.The tip effect includes the concentration of energy such as electrons,photons and magnetism in the tip region,which has promising applications in the fields of energy conversion,water capture,environmental restoration and so on.In this review,a comprehensive and systematic summary of the latest advances in the application of the tip effect in different fields is provided.Utilizing advanced Finite Difference Time Domain simulation,we further propose our understanding of the fundamental mechanism of the tip effect induced by micro-nanostructure.However,we need to forge the present study to further reveal the essential law of the tip effect from the perspective of theoretical calculations.This review would provide a solid foundation for further development and application of the tip effect.

Fano resonance-enhanced Si/MoS_(2) photodetector

In this work,a Si∕MoS_(2) heterojunction photodetector enhanced by hot electron injection through Fano resonance is developed.By preparing Au oligomers using capillary-assisted particle assembly(CAPA)on the silicon substrate with a nanohole array and covering few-layer MoS_(2) with Au electrodes on top of the oligomer structures,the Fano resonance couples with a Si∕MoS_(2) heterojunction.With on-resonance excitation,Fano resonance generated many hot electrons on the surface of oligomers,and the hot electrons were injected into MoS_(2),providing an increased current in the photodetector under a bias voltage.The photodetectors exhibited a broadband photoresponse ranging from 450 to 1064 nm,and a large responsivity up to 52 A/W at a wavelength of 785 nm under a bias voltage of 3 V.The demonstrated Fano resonance-enhanced Si∕MoS_(2) heterojunction photodetector provides a strategy to improve the photoresponsivity of two-dimensional materials-based photodetectors for optoelectronic applications in the field of visible and near-infrared detection.