Dynamic active sites on plasma engraved Ni hydroxide for enhanced electro-catalytic urea oxidation

The urea oxidization reaction(UOR)is an important anodic reaction in electro-catalytic energy conversion.However,the sluggish reaction kinetics and complex catalyst transformation in electrocatalysis require activity improvement and better mechanistic understanding of the state-of-the-art Ni(OH)_(2) catalyst.Herein,by utilizing low-temperature argon(Ar)plasma processing,tooth-wheel Ni(OH)_(2) nanosheets self-supported on Ni foam(Ni(OH)_(2)-Ar)are demonstrated to have improved UOR activity compared to conventional Ni(OH)_(2).The theoretical assessment confirms that the edge has a smaller cation vacancy formation energy than the basal plane,consequently explaining the structural formation.Operando and quasi-operando methods are employed to investigate the dynamic evolution of the Ni(OH)_(2) film in UOR.The crucial dehydrogenation products of Ni(OH)_(5)O^(-)intermediates are identified to be stable on the etched edge and explain the enhanced UOR in the low potential region.In addition,the dynamic active sites are monitored to elucidate the reaction mechanism in different potential ranges.

Nanostructured Conductive Polypyrrole for Antibacterial Components in Flexible Wearable Devices

The power generated by flexible wearable devices(FWDs)is normally insufficient to eradicate bacteria,and many conventional antibacterial strategies are also not suitable for flexible and wearable applications because of the strict mechanical and electrical requirements.Here,polypyrrole(PPy),a conductive polymer with a high mass density,is used to form a nanostructured surface on FWDs for antibacterial purposes.The conductive films with PPy nanorods(PNRs)are found to sterilize 98.2±1.6%of Staphylococcus aureus and 99.6±0.2%of Escherichia coli upon mild electrification(1 V).Bacteria killing stems from membrane stress produced by the PNRs and membrane depolarization caused by electrical neutralization.Additionally,the PNR films exhibit excellent biosafety and electrical stability.The results represent pioneering work in fabricating antibacterial components for FWDs by comprehensively taking into consideration the required conductivity,mechanical properties,and biosafety.

Hierarchical CuO-ZnO/SiO_(2) Fibrous Membranes for Efficient Removal of Congo Red and 4‑Nitrophenol from Water

Hierarchical CuO-ZnO/SiO_(2)(CZS)nanofibrous membranes are designed and fabricated to remove Congo red and 4-nitro-phenol two common small molecular pollutants in water.The electrospun SiO_(2) fibrous membrane is serves as the substrate for hydrothermal depositing CuO-ZnO nanosheets.The CZS nanofibrous membrane shows good adsorption characteristics for Congo red due to the hierarchical morphology and the adsorption kinetics where isotherm follows the pseudo-second-order model and Langmuir model,respectively.The maximum adsorption capacity for Congo red is 141.8 mg/g.Moreover,the membrane exhibits excellent catalytic reduction activity for 4-nitrophenol under mild conditions and over 96%of the pollut-ants are degraded within 90 s.The CZS nanofibrous membrane has promising prospects in applications in water treatment and environmental protection because of the good flexibility,easy fabrication,excellent adsorption,and catalytic activity.

Plasma-activated interfaces for biomedical engineering

As an important phenomenon to monitor disease development,cell signaling usually takes place at the interface between organisms/cells or between organisms/cells and abiotic materials.Therefore,finding a strategy to build the specific biomedical interfaces will help regulate information transmission and produce better therapeutic results to benefit patients.In the past decades,plasmas containing energetic and active species have been employed to construct various interfaces to meet biomedical demands such as bacteria inactivation,tissue regeneration,cancer therapy,and so on.Based on the potent functions of plasma modified surfaces,this mini-review is aimed to summarize the state-of-art plasma-activated interfaces and provide guidance to researchers to select the proper plasma and processing conditions to design and prepare interfaces with the optimal biological and related functions.After a brief introduction,plasma-activated interfaces are described and categorized according to different criteria including direct plasma-cells interfaces and indirect plasma-material-cells interfaces and recent research activities on the application of plasma-activated interfaces are described.The authors hope that this mini-review will spur interdisciplinary research efforts in this important area and expedite associated clinical applications.

Programmed surface on poly(aryl-ether-ether-ketone) initiating immune mediation and fulfilling bone regeneration sequentially

The immune responses are involved in every stage after implantation but the reported immune-regulated materials only work at the beginning without fully considering the different phases of bone healing.Here,poly(aryl-ether-ether-ketone)(PEEK)is coated with a programmed surface,which rapidly releases interleukin-10(IL-10)in the first week and slowly delivers dexamethasone(DEX)up to 4 weeks.Owing to the synergistic effects of IL-10 and DEX,an aptly weak inflammation is triggered within the first week,followed by significant M2 polarization of macrophages and upregulation of the autophagy-related factors.The suitable immunomodulatory activities pave the way for osteogenesis and the steady release of DEX facilitates bone regeneration thereafter.The sequential immune-mediated process is also validated by an 8-week implementation on a rat model.This is the first attempt to construct implants by taking advantage of both immune-mediated modulation and sequential regulation spanning all bone regeneration phases,which provides insights into the fabrication of advanced biomaterials for tissue engineering and immunological therapeutics.