We report on hydrogen adsorption and desorption on titanium-covered graphene
in order to test theoretical proposals to use of graphene functionalized with
metal atoms for hydrogen storage. At room temperature titanium islands grow
with an average diameter of about 10 nm. Samples were then loaded with
hydrogen, and its desorption kinetics was studied by thermal desorption
spectroscopy. We observe the desorption of hydrogen in the temperature range
between 400K and 700 K. Our results demonstrate the stability of hydrogen
binding at room temperature and show that hydrogen desorbs at moderate
temperatures in line with what required for practical hydrogen-storage
applications
We investigate the morphology of quasi-free-standing monolayer graphene (QFMLG) formed at several temperatures by hydrogen intercalation and discuss its relationship with transport properties. Features corresponding to incomplete hydrogen intercalation at the graphene-substrate interface are observed by scanning tunneling microscopy on QFMLG formed at 600 and 800°C. They contribute to carrier scattering as charged impurities. Voids in the SiC substrate and wrinkling of graphene appear at 1000°C, and they decrease the carrier mobility significantly. *
Phenolphthalein-modified β-CD, 1, was synthesized for the purpose of developing a new type of
guest-responsive color change indicator. The pH titration curve of 1 depends on its concentration,
suggesting that 1 exists not only as an self-inclusion form but also as an association form at a
concentration of 10-4 M in neutral aqueous solution. At pH 11.0, the association species dissociates
into the monomer one, taking a dianion form in the phenolphthalein part. Upon the guest addition
at pH 9.70, 1 exhibits the color change from colorless to purple at its concentration of 5.0 × 10-6
M due to the 1:1 host−guest complex formation. The guest-induced absorption changes were used
for molecule sensing. The sensing abilities of 1 for various guests are roughly parallel to the binding
constants.
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.