Nanoengineering of yolk-shell structured silicas for click chemistry

Nanoengineering of porous materials is of great interest for nanochemistry and practical applications. Herein, we reported the formation and its click functionalization of yolk-shell nanoparticles (YSNs) with different porous structure silicas as core. The yolk-shell structured silicas are prepared through the core-vesicle complex formation, vesicle-templating soy-gel polymerization of tetraethoxysilane (TEOS), hydrothermal treatment and calcination. The shell thickness and the void of YSNs can be regulated by changing the amount of added TEOS and solid silica core concentration. The shell of the obtained YSNs can be functionalized with thermosensitive polymers by grafting reaction and subsequent click reaction. This synthetic approach can be easily extended to other organic groups functionalized YSNs for versatile applications

Nanoengineering of yolk-shell structured silicas for click chemistry

Nanoengineering of porous materials is of great interest for nanochemistry and practical applications. Herein, we reported the formation and its click functionalization of yolk-shell nanoparticles (YSNs) with different porous structure silicas as core. The yolk-shell structured silicas are prepared through the core-vesicle complex formation, vesicle-templating soy-gel polymerization of tetraethoxysilane (TEOS), hydrothermal treatment and calcination. The shell thickness and the void of YSNs can be regulated by changing the amount of added TEOS and solid silica core concentration. The shell of the obtained YSNs can be functionalized with thermosensitive polymers by grafting reaction and subsequent click reaction. This synthetic approach can be easily extended to other organic groups functionalized YSNs for versatile applications

Effect of iron precursor on the activity and stability of PtFe/C catalyst for oxygen reduction reaction

The stability of iron species in PtFe/C catalyst in acidic medium is a grand challenge to maintain a high activity and stability for oxygen reduction reaction (ORR) via the geometric and electronic effect. Herein, we report that the use of ammonium ferric citrate with a high thermal stability, instead of iron nitrate, greatly improves the stability of iron species in PtFe/C catalyst in acidic medium after high-temperature reduction treatment. The resulting PtFe/C catalyst with ammonium ferric citrate as iron precursor shows much improved activity and stability for ORR than the counterpart using iron nitrate due to enhanced proportion of PtFe alloy in the PtFe/C catalyst. (C) 2019 Elsevier B.V. All rights reserved

Effect of iron precursor on the activity and stability of PtFe/C catalyst for oxygen reduction reaction

The stability of iron species in PtFe/C catalyst in acidic medium is a grand challenge to maintain a high activity and stability for oxygen reduction reaction (ORR) via the geometric and electronic effect. Herein, we report that the use of ammonium ferric citrate with a high thermal stability, instead of iron nitrate, greatly improves the stability of iron species in PtFe/C catalyst in acidic medium after high-temperature reduction treatment. The resulting PtFe/C catalyst with ammonium ferric citrate as iron precursor shows much improved activity and stability for ORR than the counterpart using iron nitrate due to enhanced proportion of PtFe alloy in the PtFe/C catalyst. (C) 2019 Elsevier B.V. All rights reserved