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Synergetically Selective Toluene Sensing in Hematite‐Decorated Nickel Oxide Nanocorals
Author(s) -
Suh Jun Min,
Shim YoungSeok,
Kim Do Hong,
Sohn Woonbae,
Jung Youngmo,
Lee Seon Yong,
Choi Seokhoon,
Kim Yeon Hoo,
Jeon JongMyeong,
Hong Kootak,
Kwon Ki Chang,
Park Seo Yun,
Kim Chulki,
Lee JongHeun,
Kang ChongYun,
Jang Ho Won
Publication year - 2017
Publication title -
advanced materials technologies
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.184
H-Index - 42
ISSN - 2365-709X
DOI - 10.1002/admt.201600259
Subject(s) - non blocking i/o , nanorod , hematite , materials science , nickel oxide , nickel , oxide , chemical engineering , nanostructure , heterojunction , nanotechnology , metallurgy , chemistry , catalysis , organic chemistry , optoelectronics , engineering
The decoration of p ‐type nickel oxide (NiO) with n ‐type hematite (α‐Fe 2 O 3 ) to achieve vertically ordered 1D nanostructures is an attractive strategy to enhance gas sensing properties. Herein, the authors report a facile method for α‐Fe 2 O 3 decoration of the whole surface of vertical NiO nanorods. An NiO/Fe heterostructure is deposited in multiple steps using a glancing angle deposition method, which is followed by the oxidation of Fe into α‐Fe 2 O 3 . Thermally agglomerated α‐Fe 2 O 3 nanoparticles are uniformly distributed on the whole surface of the NiO nanorods. Due to the α‐Fe 2 O 3 decoration, the NiO nanorods exhibit a coral‐like rough surface and, more interestingly, their preferential crystallographic orientation changed from (111) to (200). Compared to bare NiO nanorods, the α‐Fe 2 O 3 ‐decorated NiO nanocorals exhibit a 45.4 times higher response to 50 ppm toluene (C 7 H 8 ) at 350 °C. Their theoretical detection limit for C 7 H 8 is calculated to be ≈22 ppb. The observed unprecedented synergetic effects of α‐Fe 2 O 3 ‐decorated NiO nanocorals for the extremely selective C 7 H 8 sensing, as well as their facile synthetic route, establish a new perspective on heterostructured metal oxide 1D nanostructures for selective gas sensing.