Construction Of Metal-Based Se/Te@rGO,γ-Fe₂O₃,HSA-GO-Pd,&ZnONFs Advanced Functional Nanomaterials:Their Energy Storage And Biomedical Applications

Nanotechnology is strongly considered to be one of the most promising disciplines of science that is improved to producing objects at the nanoarchitecture-scale objects and to augment their potential in dynamic scientific fields.Metal-based constructed hybrid nanomaterials have been showing as admirable promising candidates for high-energy-density energy storage devices and against several various Gram-negative pathogenic microbes.In technology-based society,bio-fabricated nanoscale materials counting zinc oxide,iron oxide,and two semiconductor metalloids such as selenium-tellurium(Se-Te),and subsequently wrapped in reduced graphene oxide(rGO)nanosheets for emerging importance.Benefiting the significance of metal-based hybrids,we constructed and designed the preparation of zinc oxide nanoflowers,palladium nano-dots,2D iron oxide nano-sheets,and selenium-tellurium nano-rods using green methods as reductant and stabilizing agents.The designed Se/Te nanorods at graphene oxide(GO)are named Se/Te@rGO composite and two-dimensional(2D)iron oxide nanosheets are investigated as anode material in Li+ions battery.Similarly,zinc oxide nanoflowers(ZnONFs)and palladium nano-dots loaded onto graphene oxide for biological applications.The development of next-generation metal-based rechargeable batteries with high energy density,low cost,and improved safety is a great challenge with profound technological significance for portable electronics,electric vehicles,and grid-scale energy storage.Specifically,advanced metal battery chemistries call for a paradigm shift to electrodes with high metal to host ratio based on conversion or alloying mechanism,where the increased capacity is often accompanied by drastic volumetric changes,significant bond breaking,limited electronic/ionic conductivity,and unstable electrode/electrolyte interphase.Fortunately,the rapid progress of nanotechnology over the past decade has been offering battery researcher’s effective means to tackle some of the most pressing issues for nextgeneration battery chemistries.The major applications of nanotechnology in batteries can be summarized as follows:First,by reduction of the dimensions of the electrode materials,the cracking threshold of the material upon lithiation can be overcome,at the same time facilitating electron/ion transport within the electrode.Second,nanotechnology also provides powerful methods to generate various surface-coating and functionalization layers on electrode materials,protecting them from side reactions in the battery environment.Finally,nanotechnology gives people the flexibility to engineer every single component within a battery,bringing novel functions to batteries that are unachievable by conventional methods.Herein,we fabricated two semiconductor metalloids,selenium,and tellurium,into 1D architecture(Se/Te nanorods)and subsequently wrapped them in reduced graphene oxide(rGO)nanosheets.The designed Se/Te nanorods at GO are named Se/Te@rGO composite and investigated as anode material in Li+ions battery.The Se/Te@rGO electrode demonstrated an exceptional reversible storage capacity of 1456 mAh g-1 as compared to SeNr(400 mAh g-1)and Se/TeNr(800 mAh g-1)at 0.1 A g-1 after 100 cycles.Furthermore,when cycled at 5 A g-1,the Se/Te@rGO electrode presented an initial specific capacity of 804 mAh g-1 and retained a high specific capacity of 704 mAh g-1 after 3000 cycles(99.5%C.E),indicating the superior performance of the newly fabricated hybrid material.The improved electrochemical storage performance of Se/Te@rGO electrode material could be ascribed to the 1D Se/Te nanorods architecture,which can provide a shorten diffusion path for Li-ions and buffer the strain produced during charge-discharge cycles.The incorporated 2D rGO template further enhances the mechanical strength of active Se/Te material and suppresses its dissolution and volume expansion during the lithiation/delithiation process.We also demonstrate a simple and facile synthesis strategy of 2D carbon nanosheets and γ-Fe2O3 ethylene glycol iron(EG-Fe)composite as anode materials for LIBs,composed of 41.3 wt%carbon and 10.2 wt.%Fe.When used as anode materials in lithium-ion batteries(LIBs),EGFe demonstrated the enhanced initial discharge capacity of 1589 mAh g-1 at 100 mA g-1,and outstanding ultralong cycling performance with the significant stable capacity of 700 mAh g-1 and 230 mAh g-1 at the higher current rate of 0.5 A g-1 and 10 A g-1 for more than 300 and 6000 cycles,respectively.These results enable a promising avenue to design the large-scale production of 2D EG-Fe sheets-based nanostructured anode materials for next-generation LIBs for large-scale energy storage applications.Our contribution highlights substantial progress in the development of high storage materials for applications in ultra-long cycle Life Li-ion batteries.A thorough understanding of the antimicrobial mechanisms of green synthesized zinc oxidebased nanoflowers(ZnONFs)and graphene-loaded palladium-based nanoscales are critical to the manipulation of highly efficient antimicrobial nanomaterials for future bacterial infections therapy.Our projects are focused on the preparation of palladium and ZnO using natural products as reductants and stabilizing agents from different plants.Secondly,the abovementioned metals were loaded onto graphene oxide for biological applications.Finally,we rationally analyze the strengths of the proposed mechanisms and provide new insights into the remaining challenges and perspectives for future studies.Escherichia coli(E.coli)is considered the most common life-threatening infectious bacteria in our daily life and poses a major healthcare challenge.Herein,we address that near-infrared(NIR)laser excited human serum albumin(HSA)mediated graphene oxide loaded palladium nano-dots(HSA-GO-Pd)can effectively combat Gram-negative E.coli in vitro.NIR laser-excited designed hybrid material highly generating singlet oxygen as well as hydroxyl radical by electron spinresonance(ESR)analysis.Transmission electron microscopy(TEM)images show spherical small sizes pallidum nanoparticles(PdNPs)on the surface of GO nanosheets.The zeta(ζ)potential study indicates that in an aqueous medium the average PdNPs size and surface capped charge comes from HSA,HSA-GO-Pd is 5-8 nm and+25 mV,respectively.The spectroscopic characterization reveals that in the synthesized HSA-GO-Pd nanocomposite PdNPs successfully well-dispersed decorated on the surface of graphene oxide.The assynthesized HSA-GO-Pd was used against Gram-negative pathogen E.coli and shows excellent antibacterial activity and killing 95%bacteria within 5 hours.HSA-GO-Pd having very biocompatible and shows significant antibacterial activities.Furthermore,Zinc Oxide nanoflowers(ZnONFs)with low-cost,non-hazardous,and renewable phytochemicals from plant(Thlaspi arvense)extract were synthesized via facile method under controlled optimized experimental conditions.The as-fabricated zinc oxide nanoflowers were comprehensively characterized by various spectroscopic and microscopic techniques.The bio-fabricated zinc oxide nanoflowers performed an admirable potential activity against Gram-negative bacterium(E.coli)and significantly inhibited its growth,due to an intracellular generation of reactive-oxygen-species.These findings introduce a simple,inexpensive process to synthesize ZnO-NPs and HSA-GO-Pd hybrids using conventional methods without the use of sophisticated types of equipment and their application as a potent nano-antibiotic.