Nanoconfined surfactant templated electrodeposition to porous hierarchical nanowires and nanotubes

One-dimensional cobalt oxide nanotubes with rich defect for oxygen evolution reaction

For the electrochemcial hydrogen production, the oxygen evolution reaction (OER) is a pivotal half-reaction in water splitting. However, OER suffers sluggish kinetics and high overpotential, leading to the increase of overall energy consumption and decrease of the energy efficiency. In this work, high-quality cobalt oxide porous nanotubes (Co₃O₄-PNTs) are easily obtained by simple self-template approach. One-dimensional (1D) porous structure provides the large specific surface area, enough abundant active atoms and effective mass transfer. In addition, Co₃O₄-PNTs also own self-stability of 1D architecture, benefitting the their durability for electrocatalytic reaction. Thus, Co₃O₄-PNTs with optimal annealing temperature and time reveal the attractive alkaline OER performance (Tafel slope of 56 mV dec^-1and 323 mV overpotential at 10 mA cm^-2), which outperform the Co₃O₄nanoparticles and benchmark commercial RuO₂nanoparticles. Furthermore, Co₃O₄-PNTs also exhibit excellent OER durability for least 10 h at the 10 mA cm^-2. Overall, Co₃O₄-PNTs with low cost can be serve as a highly reactive and economical catalyst for OER.

Synthesis and characterization of size controlled alloy nanoparticles

Bimetallic and multimetallic alloy nanoparticles are emerging as a class of critical nanomaterials in electronic, optical and magnetic fields due to their unique physic-chemical properties. In particular, precise control of the nanoparticle size can endow them with broad versatility and high selectivity. This chapter reviews some tremendous achievements in the development of size controlled bimetallic and multimetallic alloy nanoparticles, with special emphasis on general preparation methods, characterization methodologies and instrumentation techniques. Some key factors and future perspectives on the development of size-controlled bimetallic and multimetallic alloy nanoparticles are also discussed.

Porous One-Dimensional Nanomaterials: Design, Fabrication and Applications in Electrochemical Energy Storage

Electrochemical energy storage technology is of critical importance for portable electronics, transportation and large-scale energy storage systems. There is a growing demand for energy storage devices with high energy and high power densities, long-term stability, safety and low cost. To achieve these requirements, novel design structures and high performance electrode materials are needed. Porous 1D nanomaterials which combine the advantages of 1D nanoarchitectures and porous structures have had a significant impact in the field of electrochemical energy storage. This review presents an overview of porous 1D nanostructure research, from the synthesis by bottom-up and top-down approaches with rational and controllable structures, to several important electrochemical energy storage applications including lithium-ion batteries, sodium-ion batteries, lithium-sulfur batteries, lithium-oxygen batteries and supercapacitors. Highlights of porous 1D nanostructures are described throughout the review and directions for future research in the field are discussed at the end.

Investigating the Hydrothermal Growth of Zinc Oxide Nanostructures Through Seed Layer Control

Controlling the growth of ZnO nanostructures for photovoltaic applications will ensure greater device efficiency and parameter control. This paper reports on methods to engineer the morphology and tailor the nanostructure growth direction through the hydrothermal synthesis method. Effective control is achieved through the use of a sputtered zinc layer together with modifications of the growth solution. These nanostructures have been developed with a view to incorporation into excitonic solar cells, and methods to improve surface stability using a fully aqueous synthesis method will be discussed.