High-mobility semiconductor nanotubes have demonstrated great potential for applications in high-speed transistors,single-charge detection,and memory devices.Here we systematically investigated the electronic properties of single-walled boron antimonide(BSb)nanotubes using first-principles calculations.We observed that rolling the hexagonal boron antimonide monolayer into armchair(ANT)and zigzag(ZNT)nanotubes induces compression and wrinkling effects,significantly modifying the band structures and carrier mobilities through band folding andπ^(*)-σ^(*)hybridization.As the chiral index increases,the band gap and carrier mobility of ANTs decrease monotonically,where electron mobility consistently exceeds hole mobility.In contrast,ZNTs exhibit a more complex trend:the band gap first increases and then decreases,and the carrier mobility displays oscillatory behavior.In particular,both ANTs and ZNTs could exhibit significantly higher carrier mobilities compared to hexagonal monolayer and zinc-blende BSb,reaching 10^(-3)-10^(-7) cm^(-2)·V^(-1)·s^(-1).Our findings highlight strong curvature-induced modifications in the electronic properties of single-walled BSb nanotubes,demonstrating the latter as a promising candidate for high-performance electronic devices.
The development of effective methods for obtainingmonochiral single-walledcarbonnanotubes(SWCNTs)is necessary to make many applications based on them viable for everyday use.Large-diameter semiconducting SWCNTs are particularly valuable due to their low band gap,but the isolation of such SWCNTs remains difficult to achieve as the number of possible chiralities scales strongly with diameter,and there are an overwhelming number of large-diameter SWCNT types.In this study,we demonstrate how monochiral(8,6)SWCNTs,which are 0.966 nm in diameter,can be straightforwardly harvested using the aqueous two-phase extraction(ATPE)method by employing a combination of ionic and non-ionic surfactants.The universal nature of the devised technique was demonstrated by generating fractions enriched with(8,6)SWCNTs starting from various commercially available mixtures of SWCNTs with drastically different compositions.To demonstrate the practical utility of the generated material,we studied how the obtained pure SwCNTs may be chemically modified to improve their optical characteristics.Interestingly,the course of the functionalization was highly dependent on the type of dispersant used to suspend the purified SWCNTs in the aqueous medium.
With the increasing demand for water in hydroponic systems and agricultural irrigation,viral diseases have seriously affected the yield and quality of crops.By removing plant viruses in water environments,virus transmission can be prevented and agricultural production and ecosystems can be protected.But so far,there have been few reports on the removal of plant viruses in water environments.Herein,in this study,easily recyclable biomass-based carbon nanotubes catalysts were synthesized with varying metal activities to activate peroxymonosulfate(PMS).Among them,the magnetic 0.125Fe@NCNTs-1/PMS system showed the best overall removal performance against pepper mild mottle virus,with a 5.9 log_(10)removal within 1 min.Notably,the key reactive species in the 0.125Fe@NCNTs-1/PMS system is^(1)O_(2),which can maintain good removal effect in real water matrices(river water and tap water).Through RNA fragment analyses and label free analysis,it was found that this system could effectively cleave virus particles,destroy viral proteins and expose their genome.The capsid protein of pepper mild mottle virus was effectively decomposed where serine may be the main attacking sites by^(1)O_(2).Long viral RNA fragments(3349 and 1642 nt)were cut into smaller fragments(∼160 nt)and caused their degradation.In summary,this study contributes to controlling the spread of plant viruses in real water environment,which will potentially help protect agricultural production and food safety,and improve the health and sustainability of ecosystems.
With the increasing prevalence of lithium-ion batteries(LIBs)applications,the demand for high-capacity next-generation materials has also increased.SiO_(x)is currently considered a promising anode material due to its exceptionally high capacity for LIBs.However,the significant volumetric changes of SiO_(x)during cycling and its initial Coulombic efficiency(ICE)complicate its use,whether alone or in combination with graphite materials.In this study,a three-dimensional conductive binder network with high electronic conductivity and robust elasticity for graphite/SiO_(x)blended anodes was proposed by chemically anchoring carbon nanotubes and carboxymethyl cellulose binders using tannic acid as a chemical cross-linker.In addition,a dehydrogenation-based prelithiation strategy employing lithium hydride was utilized to enhance the ICE of SiO_(x).The combination of these two strategies increased the CE of SiO_(x)from 74%to87%and effectively mitigated its volume expansion in the graphite/SiO_(x)blended electrode,resulting in an efficient electron-conductive binder network.This led to a remarkable capacity retention of 94%after30 cycles,even under challenging conditions,with a high capacity of 550 mA h g^(-1)and a current density of 4 mA cm^(-2).Furthermore,to validate the feasibility of utilizing prelithiated SiO_(x)anode materials and the conductive binder network in LIBs,a full cell incorporating these materials and a single-crystalline Ni-rich cathode was used.This cell demonstrated a~27.3%increase in discharge capacity of the first cycle(~185.7 mA h g^(-1))and exhibited a cycling stability of 300 cycles.Thus,this study reports a simple,feasible,and insightful method for designing high-performance LIB electrodes.
Chaeyeon HaJin Kyo KooJun Myoung SheemYoung-Jun Kim
The mechanical behavior of cemented gangue backfill materials(CGBMs)is closely related to particle size distribution(PSD)of aggregates and properties of cementitious materials.Consequently,the true triaxial compression tests,CT scanning,SEM,and EDS tests were conducted on cemented gangue backfill samples(CGBSs)with various carbon nanotube concentrations(P_(CNT))that satisfied fractal theory for the PSD of aggregates.The mechanical properties,energy dissipations,and failure mechanisms of the CGBSs under true triaxial compression were systematically analyzed.The results indicate that appropriate carbon nanotubes(CNTs)effectively enhance the mechanical properties and energy dissipations of CGBSs through micropore filling and microcrack bridging,and the optimal effect appears at P_(CNT)of 0.08wt%.Taking PSD fractal dimension(D)of 2.500 as an example,compared to that of CGBS without CNT,the peak strength(σ_(p)),axial peak strain(ε_(1,p)),elastic strain energy(Ue),and dissipated energy(U_(d))increased by 12.76%,29.60%,19.05%,and90.39%,respectively.However,excessive CNTs can reduce the mechanical properties of CGBSs due to CNT agglomeration,manifesting a decrease inρ_(p),ε_(1,p),and the volumetric strain increment(Δε_(v))when P_(CNT)increases from 0.08wt%to 0.12wt%.Moreover,the addition of CNTs improved the integrity of CGBS after macroscopic failure,and crack extension in CGBSs appeared in two modes:detour and pass through the aggregates.Theσ_(p)and U_(d)firstly increase and then decrease with increasing D,and porosity shows the opposite trend.Theε_(1,p)andΔε_(v)are negatively correlated with D,and CGBS with D=2.150 has the maximum deformation parameters(ε_(1,p)=0.05079,Δε_(v)=0.01990)due to the frictional slip effect caused by coarse aggregates.With increasing D,the failure modes of CGBSs are sequentially manifested as oblique shear failure,"Y-shaped"shear failure,and conjugate shear failure.
It has made significant progress in catalyst andreactor design for commercial current densities in CO_(2) electroreduction(CO_(2)ER).However,these catalyst systems haverarely been applied for a C2 gas product of ethane due to itscommonly inferior selectivity relative to other C1 and C2products.Herein,bamboo-like amorphous Ni(OH)_(2) nanotubes wrapped Cu nanoparticles composite(Cu NPs@aNi(OH)_(2)NTs)are constructed for selective CO_(2)ER to ethane ina flow cell.The unique structure of Cu NPs@a-Ni(OH)_(2) NTsprovides a confined geometry to improve the adsorption of thereactive species.The interface of Cu NPs and a-Ni(OH)_(2) NTs isstabilized by generating some NiOH species.The producedCu@NiOH interface enhances the activation of CO_(2) to*C*OOH and strengthens the adsorption of*COL on Cu sitefor more*COH formation and its dimerization for finalethane production.Meanwhile,amorphous Ni(OH)_(2) nanotubes promote water dissociation for the hydrogenation ofcarbonous intermediates,contributing to ethane production.The synthesized Cu NPs@a-Ni(OH)_(2) NTs can reach a Faradaicefficiency of 48.3%and a partial current density of−226.7 mA cm^(−2) for ethane at−0.7 V in a flow cell,with aremarkable stability for 24 h.This work provides a rationalstrategy to engineer Cu-based composite for selective CO_(2)ERto ethane in a flow cell.
