It is well-established that a high
specific surface area and more
active sites are the key factors for excellent gas sensing performances.
Corrugated-morphology materials expose large surface areas and a variety
of low-coordination atoms, which can promote gas adsorption and catalyze
sensing reactions. In this work, corrugated cobalt titanate/partially
reduced graphene oxide (CoTiO3/prGO) heterogeneous sensing
materials are prepared by a sol–gel method combined with a
controlled chemical reduction process. A green and ecofriendly reducing
agent ascorbic acid (VC) is used to regulate the reduction process.
An appropriate dosage of VC induces partial removal of functional
groups from graphene oxide (GO) together with a periodical relaxation
of the aromatic plane, forming a corrugated-morphology prGO. Excessive
use of VC leads to asymmetrical or random removal of functional groups,
leading to a wrinkled or porous morphology. The obtained corrugated
CoTiO3/prGO exhibits high sensitivity to the isopentanol
molecule. The response value reaches 30.1–100 ppm isopentanol,
which is 3.2–10.4 times that of pentanol, pentanal, glutaral,
and methylcyclopentane. The selectivity of CoTiO3/prGO
to isopentanol is attributed to the corrugated morphology, the abundant
C–O–Ti chemical bonds as activated adsorption sites,
and the heterogeneous interfaces. This work offers a mild chemical
reduction strategy to effectively regulate the morphological revolution,
heterojunction formation, and selective sensing performance of the
CoTiO3/prGO composite.