Shuang Lin,Xiang Lin,Xueying Song,Siqingaowa Han,Li Wang,Wuliji Hasi
Surface-enhanced Raman scattering (SERS) substrate is the key to SERS technology and it is still a basic focus to fabricate desirable SERS substrates offering multiple advantages of strong Raman enhancement and good reproducibility and portability. A flexible paper-based SERS substrate were fabricated involving the use of Au nanocubes (NCs) monolayer. Au NCs were generated with tunable size in the range of 24 to 63 nm through seed-mediated growth method. The effect of support on SERS properties of Au NCs–assembled monolayer was systemically explored. As a result, more excellent SERS performance could be obtained by assembling Au NCs on the filter paper. Besides, the influence of Au NCs' size on SERS-enhanced effect of paper-based substrate was also investigated. Our results clearly indicated that paper-based substrate with 39 nm Au NCs possessed the optimal SERS enhancement. This SERS substrate exhibited high sensitivity with enhancement factor (EF) up to 9.75 × 10 7 and demonstrated good uniformity and time stability. Furthermore, based on this superior paper-based SERS substrate with advantage of powerful sample extraction performance, the measurement of crystal violet (CV) on shell surface were successfully carried out with detection limit down to 2.17 × 10 −7 M. And linear quantification were achieved in the range from 5 × 10 −5 to 5 × 10 −7 M. To sum up, the as-prepared SERS substrate is applicable for on-site detection and analysis of CV on various shell surfaces.
Meliorating the particle surface could alter the surface properties, thus potentially enhancing the electrode reactions. In this assignment, a recovery of the intrinsic nanostructure at La 1.2 Sr 0.8 Ni 0.5 Mn 0.5 O 4+δ (LSNM) particle surface with the elimination of the bi-shell nano-surface layers caused by dopant segregation was attempted based on the lower powder calcination temperature and introduction of A-site cation deficiency. The A-site deficient (La 1.2 Sr 0.8 ) 0.9 Ni 0.5 Mn 0.5 O 4+δ [D-LSNM], accompanied with no phase separation on surface, is successfully obtained, in which the smaller particles and more oxygen vacancies would promote the electrocatalysis, oxygen reduction reaction and oxygen migration, thus boosting the electrode reactions. The surface nanostructure-recovered D-LSNM cathode achieves a preeminent performance with power output of 1547 and 1030 mW cm −2 at 700 and 600 °C, being better than other K 2 NiF 4 -type R-P cathodes in the literature. Anyhow, the preferable cell performance along with the fine stability suggests that the original surface-nanostructured D-LSNM is a promising cathode alternative for low-temperature proton-conducting solid oxide fuel cells. This work provides a new kind of reverse thinking to design highly catalytically active cathode materials via the restoration of the intrinsic nanostructure at surface, which would be beneficial to the related electrocatalytic fields.
Qianyu Zhao,Haitian Zhao,Weiwei Huang,Xin Yang,Lei Yao,Jia Liu,Jiaqi Li,Jing Wang
In this work, novel water-compatible core–shell surface molecularly imprinted polymers with double recognition abilities for highly efficient separation of starch polysaccharide were prepared. The double recognition abilities of the molecularly imprinted polymers were achieved by adopting 3-aminophenyl boronic acid and 2-acrylamide-2-methyl propanesulfonic acid as functional monomers. Molecularly imprinted polymers could specifically recognize and capture starch molecules in aqueous solutions which was guaranteed by these functional groups and shape of imprinted cavities. The starch molecularly imprinted polymers showed a short kinetic equilibrium time, high selectivity compared to glucans of different molecular weights (G70 000, G10 000, and G50 00), and satisfactory adsorption capacity for starch. The binding capacity and the imprinting factor of the starch molecularly imprinted polymers could reach 13.08 mg g−1 and 2.22, respectively. Many favorable capabilities of the starch molecularly imprinted polymers also provide the basis for further application in the future. Furthermore, the adsorption mechanism of starch molecularly imprinted polymers was researched in detail by using an adsorption model.
危险品化学品经营许可证（带存储）