Ultrathin PtPdCu Nanowires Fused Porous Architecture with 3D Molecular Accessibility: An Active and Durable Platform for Methanol Oxidation

It is desirable but challenging to develop active and durable low-Pt catalysts for next-generation fuel cells. Herein, a three-dimensional porous PtPdCu architecture with ultrathin nanowires was obtained through a simple, rapid and aqueous method. This PtPdCu catalyst showed the remarkable performance for methanol oxidation reaction with a 6.5 times enhancement in precious-metal-based mass activity, a 7.2 times enhancement in specific activity and a better durability in comparison with a standard Pt/C catalyst. According to the structure–activity analysis, these enhancements were due to the beneficial structural feature and the multicomponent synergy effect

Photocurrent Response in Multiwalled Carbon Nanotube Core–Molybdenum Disulfide Shell Heterostructures

In this report, a few-layer molybdenum disulfide (MoS₂) shell was coated on core multiwalled carbon nanotube (CNT) by a facile solvothermal method. The morphology and high crystallinity of this structure were demonstrated and verified by transmission electron microscopy (TEM), X-ray diffraction (XRD), Raman spectroscopy, and X-ray photoelectron spectroscopy (XPS). After being integrated into a planar device, the CNT–MoS₂ core–shell structure exhibits clear photoresponse and a wide response range upon laser illumination. In addition, the device shows a bias-dependent and position-sensitive photocurrent effect. Further experiments show that larger photocurrent was obtained under laser illumination with longer wavelength. Both the photocurrent and response speed are enhanced when the device is placed under vacuum condition. The simple material synthesis and device fabrication method used in this work may provide a practical strategy for low-cost and large-scale optical applications

Monodispersed Ru Nanoparticles Functionalized Graphene Nanosheets as Efficient Cathode Catalysts for O₂‑Assisted Li–CO₂ Battery

In Li–CO₂ battery, due to the highly insulating nature of the discharge product of Li₂CO₃, the battery needs to be charged at a high charge overpotential, leading to severe cathode and electrolyte instability and hence poor battery cycle performance. Developing efficient cathode catalysts to effectively reduce the charge overpotential represents one of key challenges to realize practical Li–CO₂ batteries. Here, we report the use of monodispersed Ru nanoparticles functionalized graphene nanosheets as cathode catalysts in Li–CO₂ battery to significantly lower the charge overpotential for the electrochemical decomposition of Li₂CO₃. In our battery, a low charge voltage of 4.02 V, a high Coulomb efficiency of 89.2%, and a good cycle stability (67 cycles at a 500 mA h/g limited capacity) are achieved. It is also found that O₂ plays an essential role in the discharge process of the rechargeable Li–CO₂ battery. Under the pure CO₂ environment, Li–CO₂ battery exhibits negligible discharge capacity; however, after introducing 2% O₂ (volume ratio) into CO₂, the O₂-assisted Li–CO₂ battery can deliver a high capacity of 4742 mA h/g. Through an in situ quantitative differential electrochemical mass spectrometry investigation, the final discharge product Li₂CO₃ is proposed to form via the reaction 4Li⁺ + 2CO₂ + O₂ + 4e^– → 2Li₂CO₃. Our results validate the essential role of O₂ and can help deepen the understanding of the discharge and charge reaction mechanisms of the Li–CO₂ battery