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Multifunctional Materials: A Case Study of the Effects of Metal Doping on ZnO Tetrapods with Bismuth and Tin Oxides
Author(s) -
Postica Vasile,
Gröttrup Jorit,
Adelung Rainer,
Lupan Oleg,
Mishra Abhishek Kumar,
de Leeuw Nora H.,
Ababii Nicolai,
Carreira José F. C.,
Rodrigues Joana,
Sedrine Nebiha Ben,
Correia Maria Rosário,
Monteiro Teresa,
Sontea Victor,
Mishra Yogendra Kumar
Publication year - 2017
Publication title -
advanced functional materials
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 6.069
H-Index - 322
eISSN - 1616-3028
pISSN - 1616-301X
DOI - 10.1002/adfm.201604676
Subject(s) - materials science , bismuth , doping , tin oxide , schottky barrier , molecule , density functional theory , tin , nanotechnology , metal , fermi level , oxide , chemical physics , optoelectronics , computational chemistry , chemistry , physics , organic chemistry , diode , quantum mechanics , metallurgy , electron
Hybrid metal oxide nano‐ and microstructures exhibit novel properties, which make them promising candidates for a wide range of applications, including gas sensing. In this work, the characteristics of the hybrid ZnO‐Bi 2 O 3 and ZnO‐Zn 2 SnO 4 tetrapod (T) networks are investigated in detail. The gas sensing studies reveal improved performance of the hybrid networks compared to pure ZnO‐T networks. For the ZnO‐T‐Bi 2 O 3 networks, an enhancement in H 2 gas response is obtained, although the observed p‐type sensing behavior is attributed to the formed junctions between the arms of ZnO‐T covered with Bi 2 O 3 and the modulation of the regions where holes accumulate under exposure to H 2 gas. In ZnO‐T‐Zn 2 SnO 4 networks, a change in selectivity to CO gas with high response is noted. The devices based on individual ZnO‐T‐Bi 2 O 3 and ZnO‐T‐Zn 2 SnO 4 structures showed an enhanced H 2 gas response, which is explained on the basis of interactions (electronic sensitization) between the ZnO‐T arm and Bi 2 O 3 shell layer and single Schottky contact structure, respectively. Density functional theory‐based calculations provide mechanistic insights into the interaction of H 2 and CO gas molecules with Bi‐ and Sn‐doped ZnO(0001) surfaces, revealing changes in the Fermi energies, as well as charge transfer between the molecules and surface species, which facilitate gas sensing.