Ambient rutile VO2(R) hollow hierarchitectures with rich grain boundaries from new-state nsutite-type VO2, displaying enhanced hydrogen adsorption behavior

Abstract

Modulating the interaction between small gas molecules and solid host materials is becoming increasingly important for the future society due to the alternative energy resources especially for the hydrogen energy. As is known, two catalogues of materials such as two-dimensional (2D) lamellar cavity structures and three-dimensional (3D) infinite tunnel structures have received intensive considerations during the past decades. Herein, we put forward a new alternative that the solid materials with synergic effects of grain-boundary-rich (GBR) structure and 3D hierarchical hollow structure would also be a promising candidate for modulating the gas molecules in solid adsorbents. As expected, our constructed novel 3D hollow hierarchitectures with GBR shells standing on the hollow spherical cavity indeed resulted in the enhanced hydrogen adsorption behavior. The as-prepared 3D hollow hierarchitectures were very uniform in large scale, and the very simple reaction process offers high convenience, short reaction time, and no need for any complex manipulations or equipments. The hollow outlook of the rutile VO₂(R) 3D hierarchitectures is the reminiscence of the hollow cavity of nsutite-type VO₂, while the formation of the VO₂(R) GBR structure is attributed to volume shrink from a unique intergrowth structure of nsutite-type VO₂. The novel gas modulation model with the synergic effect of GBR structure and hierarchical hollow structure may pave a new way for developing materials in energy and environmental fields in the near future.