Owing to its high storag
e capacity (10.8 mass %), sodium borohydrid
e (NaBH
4) is a promising hydrog
en storag
e mat
eria
l. How
ev
er, th
e t
emp
eratur
e for hydrog
en r
eleas
e is high (>500 掳C), and r
ev
ersibi
lity of th
e r
eleas
e is unachi
evab
le und
er r
easonab
le conditions. H
er
ein, w
e d
emonstrat
e th
e pot
entia
l of a nov
el strat
egy
leading to high and stab
le hydrog
en absorption/d
esorption cyc
ling for NaBH
4 und
er mi
ld pr
essur
e conditions (4 MPa). By an antiso
lv
ent pr
ecipitation m
ethod, th
e siz
e of NaBH
4 partic
les was r
estrict
ed to a f
ew nanom
et
ers (&
lt;30 nm), r
esu
lting in a d
ecr
eas
e of th
e m
elting point and an initia
l r
eleas
e of hydrog
en at 400 掳C. Furth
er
encapsu
lation of th
es
e nanopartic
les upon r
eaction of nick
el ch
lorid
e at th
eir surfac
e a
llow
ed th
e synth
esis of a cor
e鈥搒h
ell nanostructur
e, NaBH
4@Ni, and this provid
ed a rout
e for (a) th
e eff
ectiv
e nanoconfin
em
ent of th
e m
elt
ed NaBH
4 cor
e and its d
ehydrog
enation products, and (b) r
ev
ersibi
lity and fast kin
etics owing to short diffusion
lengths, th
e unstab
le natur
e of nick
el borohydrid
e, and possib
le modification of r
eaction paths. H
enc
e at 350 掳C, a r
ev
ersib
le and st
eady hydrog
en capacity of 5 mass % was achi
ev
ed for NaBH
4@Ni; 80% of th
e hydrog
en cou
ld b
e d
esorb
ed or absorb
ed in
less than 60 min, and fu
ll capacity was r
each
ed within 5 h. To th
e b
est of our know
ledg
e, this is th
e first tim
e that such p
erformanc
es hav
e b
een achi
ev
ed with NaBH
4. This d
emonstrat
es th
e pot
entia
l of th
e strat
egy in
leading to major advanc
em
ents in th
e d
esign of
eff
ectiv
e hydrog
en storag
e mat
eria
ls from pristin
e borohydrid
es.
Keywords:
ef="http://pubs.acs.org/action/doSearch?action=search&searchText=sodium+borohydride&qsSearchArea=searchText">sodium borohydride; ef="http://pubs.acs.org/action/doSearch?action=search&searchText=NaBH4&qsSearchArea=searchText">NaBH4; ef="http://pubs.acs.org/action/doSearch?action=search&searchText=nickel&qsSearchArea=searchText">nickel; ef="http://pubs.acs.org/action/doSearch?action=search&searchText=nanoparticle&qsSearchArea=searchText">nanoparticle; ef="http://pubs.acs.org/action/doSearch?action=search&searchText=core%E2%88%92shell&qsSearchArea=searchText">core鈭抯hell; ef="http://pubs.acs.org/action/doSearch?action=search&searchText=hydrogen+storage&qsSearchArea=searchText">hydrogen storage; ef="http://pubs.acs.org/action/doSearch?action=search&searchText=reversibility&qsSearchArea=searchText">reversibility