We
demonstrate using single molecule spectroscopy that inorganic
CsPbI3 perovskite quantum dots (PQDs) undergo an irreversible,
photoaccelerated reaction with water that results in a blue-shift
of the photoluminescence (PL) and ultimately to complete quenching
of the emission. We find that decomposition does not take place in
the presence of oxygen alone but that it requires light and water.
We also analyze the blinking for some stable PQDs and find a continuous
distribution of emission states with a linear correlation between
intensity and lifetime. We postulate that, in addition to charging
and discharging processes, blinking arises from the activation and
deactivation of nonradiative recombination centers in the PQDs.
The carbon monoxide dehydrogenase was purified from Clostridium thermoaceticum to apparent homogeneity. The 120‐fold purified enzyme with app. M
r 250000 had a nickel content of 10 ± 2 μmol Ni/protein.
Growth of Acetobacterium woodii on H2 and CO2 rather than on fructose was dependent on nickel. Nickel-deprived cultures growing on fructose did not synthesize acetate from CO2; under these conditions hydrogen formation was used as the electron sink. The data indicate that nickel is involved in CO2 reduction to acetate in A. woodii.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.