A General Nanocoating Method via Photoinduced Self-Initiation

Hybrid core-shell nanoparticles play a very significant role in many applications. Here, we report a light-induced oligomer coating on nanoparticles via Norrish type I reaction. The radical species generated via UV irradiation can chemically initiate the photoinitiators, which are then polymerized and deposited on inorganic nanoparticles via heterogeneous nucleation, forming a soft oligomer coating smaller than 40 nm. This coating method is versatile and potentially applicable to many different types of inorganic cores and their assemblies, making it a very useful technique for "freezing" nanoassemblies in solution. Moreover, these oligomer coatings containing radical species can also initiate surface polymerization of both styrenic and acrylic monomers with certain functionalities for different applications such as self-assembly, plasmon tuning, and pH sensing (3.5-4.5).

Decomposition behavior and reaction mechanism of Ce0.67Tb0.33MgAl11O19 during Na2CO3 assisted roasting: Toward efficient recycling of Ce and Tb from waste phosphor

Waste aluminate phosphor is a valuable secondary resource of rare earth elements (REEs). However, Ce and Tb in aluminate green phosphor can hardly be extracted by direct leaching in an inorganic acid. Therefore, Na₂CO₃ assisted roasting is adopted to decompose the stable spinel structure of Ce_0.67Tb_0.33MgAl₁₁O₁₉ in the present work and to achieve the transformation of REEs to simple oxides. Based on the thermodynamic calculations, systematic experiments of thermal decomposition have been conducted. The thermal decomposition behavior, phase evolution, valence state change, variations in micro and macro morphology of the green phosphor during Na₂CO₃ assisted roasting were examined by using TG-DSC/MS, XRD, XPS, SEM/EDS analyses. The results indicated that the green phosphor began to react with solid Na₂CO₃ at 800 °C, and the reaction was dramatically accelerated with temperature rising above 851 °C. At about 1000 °C, Ce_0.67Tb_0.33MgAl₁₁O₁₉ could completely decomposed into CeO₂, Tb₂O₃ and MgO by roasting in an equivalent mass of Na₂CO₃ for 2 h, while α-Al₂O₃ was hardly attacked in roasting. The decomposition mechanism of Ce_0.67Tb_0.33MgAl₁₁O₁₉ in molten Na₂CO₃ could be depicted by the unreacted shrinking core model, and the reaction rate constant was estimated at approximately nanometers per second. The synergistic effect of cation-oxoanion ensures the successful extraction of CeO₂ and Tb₂O₃ from the green phosphor via Na₂CO₃ assisted roasting method. The converted CeO₂ and Tb₂O₃ can be extracted by using chlorination roasting and separated from non-REE residues. According to these investigations, a new efficient process technology is proposed for sustainable recycling of waste phosphor.

Flower-like polyaniline–NiO structures: a high specific capacity supercapacitor electrode material with remarkable cycling stability

In this study, we report a binder-free in situ approach to synthesize a polyaniline–NiO composite on a nickel foam as a supercapacitor electrode.