The impact of surface Cu2+ of ZnO/(Cu1- x Zn x )O heterostructured nanowires on the adsorption and chemical transformation of carbonyl compounds

Jiangyang Liu; Kazuki Nagashima; Yuki Nagamatsu; Takuro Hosomi; Hikaru Saito; Chen Wang; Wataru Mizukami; Guozhu Zhang; Benjarong Samransuksamer; Tsunaki Takahashi; Masaki Kanai; Takao Yasui; Yoshinobu Baba; Takeshi Yanagida

doi:10.1039/d1sc00729g

The impact of surface Cu²⁺ of ZnO/(Cu_{1- x} Zn _x )O heterostructured nanowires on the adsorption and chemical transformation of carbonyl compounds

Chem Sci. 2021 Mar 8;12(14):5073-5081. doi: 10.1039/d1sc00729g.

Authors

Jiangyang Liu¹, Kazuki Nagashima^{1

2}, Yuki Nagamatsu³, Takuro Hosomi^{1

2}, Hikaru Saito³, Chen Wang³, Wataru Mizukami^{2

4

5}, Guozhu Zhang¹, Benjarong Samransuksamer¹, Tsunaki Takahashi^{1

2}, Masaki Kanai³, Takao Yasui^{2

6}, Yoshinobu Baba⁶, Takeshi Yanagida^{1

3}

Affiliations

¹ Department of Applied Chemistry, Graduate School of Engineering, The University of Tokyo 7-3-1 Hongo Bunkyo-ku Tokyo 113-8656 Japan kazu-n@g.ecc.u-tokyo.ac.jp yanagida@g.ecc.u-tokyo.ac.jp.
² Japan Science and Technology Agency (JST), PRESTO 4-1-8 Honcho, Kawaguchi Saitama 332-0012 Japan.
³ Institute for Materials Chemistry and Engineering, Kyushu University 6-1 Kasuga-Koen Kasuga Fukuoka 816-8580 Japan.
⁴ Center for Quantum Information and Quantum Biology, Institute for Open and Transdisciplinary Research Initiatives, Osaka University 1-3 Machikaneyama Toyonaka Osaka 560-8531 Japan.
⁵ Graduate School of Engineering Science, Osaka University 1-3 Machikaneyama Toyonaka Osaka 560-8531 Japan.
⁶ Department of Biomolecular Engieering, Graduate School of Engineering, Nagoya University Furo-cho, Chikusa-ku Nagoya 464-8603 Japan.

Abstract

The surface cation composition of nanoscale metal oxides critically determines the properties of various functional chemical processes including inhomogeneous catalysts and molecular sensors. Here we employ a gradual modulation of cation composition on a ZnO/(Cu_1-x Zn _x )O heterostructured nanowire surface to study the effect of surface cation composition (Cu/Zn) on the adsorption and chemical transformation behaviors of volatile carbonyl compounds (nonanal: biomarker). Controlling cation diffusion at the ZnO(core)/CuO(shell) nanowire interface allows us to continuously manipulate the surface Cu/Zn ratio of ZnO/(Cu_1-x Zn _x )O heterostructured nanowires, while keeping the nanowire morphology. We found that surface exposed copper significantly suppresses the adsorption of nonanal, which is not consistent with our initial expectation since the Lewis acidity of Cu²⁺ is strong enough and comparable to that of Zn²⁺. In addition, an increase of the Cu/Zn ratio on the nanowire surface suppresses the aldol condensation reaction of nonanal. Surface spectroscopic analysis and theoretical simulations reveal that the nonanal molecules adsorbed at surface Cu²⁺ sites are not activated, and a coordination-saturated in-plane square geometry of surface Cu²⁺ is responsible for the observed weak molecular adsorption behaviors. This inactive surface Cu²⁺ well explains the mechanism of suppressed surface aldol condensation reactions by preventing the neighboring of activated nonanal molecules. We apply this tailored cation composition surface for electrical molecular sensing of nonanal and successfully demonstrate the improvements of durability and recovery time as a consequence of controlled surface molecular behaviors.