@article {560,
	title = {Insertion and removal of protons in single-crystal orthorhombic molybdenum trioxide under H2S/H-2 and O-2/N-2},
	journal = {Chemistry of Materials},
	volume = {14},
	number = {4},
	year = {2002},
	note = {ISI Document Delivery No.: 542DRTimes Cited: 13Cited Reference Count: 49},
	month = {Apr},
	pages = {1788-1796},
	type = {Article},
	abstract = {Using AFM/XRD/XPS methods, in this paper, we investigate protonation and deprotonation processes in single-crystal samples of orthorhombic molybdenum trioxide (alpha-MoO3). At low temperatures, a small part of alpha-MoO3 is changed to needlelike HxMoO3 (x approximate to 0.33) along <203> directions in a H2S/H-2 gas stream. When these elongated crystallites assemble into a maze structure, the growth of HxMoO3 is gradually ceased due to closing entrance for hydrogen. At higher temperatures, the needlelike HxMoO3 crystallites turn to a growth perpendicular to <203>, which leads to the formation of HxMoO3 blocks. It is observed that the basal plane of alpha-MoO3 is severely buckled upon the protonation. Surface sulfidation is also observed. The formed HxMoO3 or surface MOS2, however, can be readily converted back to their original-phase alpha-MoO3 in air at 350-400 degreesC. This oxidation process gives rise to a flattened (010) topography (i.e., debuckling) on which shallowly divided alpha-MoO3 surface blocks bounded with {101} planes are formed. When an alpha-MoO3 (010) plane embedded with nanocrystallites is used to create surface stress or nucleation sites, the insertion mode of hydrogen along <001> is further reconfirmed in this work. A correlation of surface/bulk phases upon various chemical reactions is addressed, and a model to summarize these changes is also proposed.},
	keywords = {BRONZES, DECOMPOSITION, GROWTH, HXMOO3, HYDROGEN, MOO3, NUCLEAR-MAGNETIC-RESONANCE, RAY PHOTOELECTRON-SPECTROSCOPY, SILICA SUPPORTS, THIN-FILMS, XPS},
	isbn = {0897-4756},
	url = {<Go to ISI>://000175028700050},
	author = {Zeng, H. C. and Xie, F. and Wong, K. C. and Mitchell, K. A. R.}
}
