0000000000699623
AUTHOR
Virgīnija Vītola
CO2 turned into a nitrogen doped carbon catalyst for fuel cells and metal–air battery applications
Heteroatom doped metal-free catalysts are one of the most promising replacements for platinum for the alkaline oxygen reduction reaction (ORR). Due to the lack of metal atoms, they are extremely stable and environmentally friendly. However, production of carbon nanomaterials can have a very high CO2 footprint. In this study, we present ORR catalysts made directly from CO2via molten salt CO2 electrolysis. The deposited carbon powder is doped with nitrogen using pyrolysis in the presence of dicyandiamide. The effect of molten carbonate electrolyte composition towards the final ORR activity in 0.1 M KOH is studied. A thorough physico-chemical study of the starting carbons and N-doped catalysts…
Electronic excitations and processes in long lasting luminescence material SrAl2O4
Persistent luminescent material SrAl2O4: Eu2+, Dy3+ is widely used and studied for energy efficient applications. A study of SrAl2O4:Eu,Dy; SrAl2O4:Dy, and undoped SrAl2O4 material was conducted. Improvements for the mechanism of persistent luminescence have been suggested, that involve tunnelling of electron from trapping center to Eu3+, and the proof for stable Dy4+ existence in strontium aluminate has been presented. Undoped material luminescence has been observed, consisting of trace impurity and intrinsic defects luminescence. The results of this work give new knowledge and improve the existing concepts of persistent luminescence in Eu activated strontium aluminates. They also open som…