Submicrometer-sized LiNi 1/3 Co 1/3 Mn 1/3 O 2 (NCM111) crystals with homogeneous composition are prepared via a polymer-chelation chemical solution process. The complexed chelate agents of ethylenediaminetetraacetic acid (EDTA) and polyethyleneimine (PEI) could chelate all metal ions in one step, with intimate mixing at the atomic level, ensuring a homogeneous ion distribution in the product. The as-prepared NCM111 crystals have a narrow particle size distribution with an average size of 250 nm, which can effectively shorten the lithium ion diffusion path. In addition, the NCM111 crystals majorly consist of electrochemically active {010} facets and low Li + /Ni 2+ cation mixing, thus delivering a high reversible discharge capacity of 156.1 mAh g −1 after 100th cycles and good rate capability of 102.7 mAh g −1 at 10 C. Furthermore, it is found that the induction of excess Li could deteriorate the rate capability and increase the Li + solid-state diffusion resistance. However, Al 3+ doping could effectively improve the cycling performance, while Nb 5+ doping could increase significantly the discharge capacity as well as rate capability. Owing to the flexibility of the chelating chemistry , the synthesis should be extended to prepare other multicomponent single-crystal cathodes with homogeneous composition and desired substation.
A novel metal-organic framework (MOF) synergized with Polyethyleneimine (PEI) functionalized hydrophilic magnetic nanosphere with two kinds of biological friendly metal ions (Fe 3 O 4 @PDA@MIL(Ti)-PEI-Nb) was fabricated and synthesized to enrich global phosphopeptides in complex biological samples. Based on the preference of Ti 4+ towards mono-phosphopeptides and the preference of Nb 5+ towards multi-phosphopeptides as well as the strong cationic charge density environment created by the high protonation of branched-PEI in acidic solution, the material performed prominently in the phosphopeptides enrichment, both in the standard protein for simulation and the three typical practical biological samples. The obtained material exhibits extremely high sensitivity (0.1 fmol), good selectivity (molar ratio of β-casein: BSA=1:5000), and excellent enrichment ability such as capturing 34 phosphopeptides from saliva. The combination of the comprehensive enrichment performance and biocompatibility presents a broad application prospect in phosphorylated proteomics.
Chun Tong,Liquan Jing,Minqiang He,Meng Xie,Wei Wei,Yuanguo Xu,Hui Xu,Huaming Li
Designing a green and efficient catalyst to effectively degrade antibiotics is still one of the hot topics of research. Firstly, 1D nanorod Fe 2 O 3 /NaNbO 3 composite was successfully prepared by the two steps strategy through hydrothermal combined calcination method. In addition, the photocatalytic activity of the samples was evaluated by the degradation of tetracycline (TC) under visible light irradiation. The test results show that the 5% Fe 2 O 3 /NaNbO 3 nanorod material exhibits superior degradation rate of TC (89.4% removal efficiency in 90 min), and shows 5.62 times than that of NaNbO 3 nanorods. Under UV–visible light irradiation, 5% Fe 2 O 3 /NaNbO 3 nanorod composite with H 2 O 2 solution can degrade 97.4% of TC in 60 min, which is 12.1 times greater to that of the pure NaNbO 3 nanorods. The outstanding degradation performance may be attributed to the introduction of Fe 2 O 3 nanoparticles, which can activate H 2 O 2 more efficiently and produce more free radicals to degrade pollutants. At the same time, the 5% Fe 2 O 3 /NaNbO 3 nanorod composite can also act as an activate persulfate (PS) and generate SO 4 − to efficiently degrade TC. In addition, the catalyst also showed good performance in degrading TC in the presence of different anions and cations. Plant growth experiment ( mung bean seeds ) results showed that the degradation products have obvious lower toxicity. This study provides new domain about the designing of a photo-Fenton catalyst having dual ion synergy (Fe 3+ /Fe 2+ and Nb 5+ /Nb 4+ ) and full spectrum response.