Abstract
Herein,a novel TiO2/CN heterojunction material has been prepared by one-step bubble template-assisted calcination to enhance the hydrogen storage capability of LiAlH4.The TEM,XPS and UPS analysis confirm that a heterostructure is formed between TiO2 and g-C3N4 successfully.The experimental findings indi-cate that the TiO2/CN significantly enhances the dehydrogenation performance of LiAlH4.For instance,the LiAlH4-7 wt％TiO2/CN starts to dehydrogenize at 76 ℃(94 ℃ less than pure LiAlH4)and releases 6.5 wt％H2 at 200 ℃.Meanwhile,LiAlH4-7 wt％TiO2/CN releases 4.9 wt％H2 at 120 ℃ within 50 min.The mech-anism analysis illustrates that AlTi3N is formed in situ during ball-milling.And density functional theory(DFT)calculation results reveal that the AlTi3N can weaken the Al-H bonds in LiAlH4 through interfacial charge transfer.Furthermore,the TiO2/CN heterostructure creates an internal electric field that generates an electron-rich layer.As a result,the negative electron layer at one end of the TiO2/CN heterojunction has an increased affinity for H,which enhances the dehydrogenation reaction of LiAlH4.Clearly,both the TiO2/CN heterostructure and AlTi3N contribute to the improvement of the dehydrogenation properties of LiAlH4.
NETL
NSTL
万方数据