Photo-catalytic activities of plant hormones on semiconductor nanoparticles by laser-activated electron tunneling and emitting.
Understanding of the dynamic process of laser-induced ultrafast electron tunneling is still very limited. It has been thought that the photo-catalytic reaction of adsorbents on the surface is either dependent on the number of resultant electron-hole pairs where excess energy is lost to the lattice through coupling with phonon modes, or dependent on irradiation photon wavelength. We used UV (355 nm) laser pulses to excite electrons from the valence band to the conduction band of titanium dioxide (TiO₂), zinc oxide (ZnO) and bismuth cobalt zinc oxide (Bi₂O₃)₀.₀₇(CoO)₀.₀₃(ZnO)₀.₉ semiconductor nanoparticles with different photo catalytic properties. Photoelectrons are extracted, accelerated in a static electric field and eventually captured by charge deficient atoms of adsorbed organic molecules. A time-of-flight mass spectrometer was used to detect negative molecules and fragment ions generated by un-paired electron directed bond cleavages. We show that the probability of electron tunneling is determined by the strength of the static electric field and intrinsic electron mobility of semiconductors. Photo-catalytic dissociation or polymerization reactions of adsorbents are highly dependent on the kinetic energy of tunneling electrons as well as the strength of laser influx. By using this approach, photo-activities of phytohormones have been investigated.
Key Laboratory of Pesticides and Chemical Biology, Ministry of Education, College of Chemistry, Central China Normal University, Wuhan, Hubei 430079, P. R. China.
Xuemei
X
Tang
Key Laboratory of Pesticides and Chemical Biology, Ministry of Education, College of Chemistry, Central China Normal University, Wuhan, Hubei 430079, P. R. China.
Lulu
L
Huang
Key Laboratory of Pesticides and Chemical Biology, Ministry of Education, College of Chemistry, Central China Normal University, Wuhan, Hubei 430079, P. R. China.
Wenyang
W
Zhang
Key Laboratory of Pesticides and Chemical Biology, Ministry of Education, College of Chemistry, Central China Normal University, Wuhan, Hubei 430079, P. R. China.
Ruowei
R
Jiang
Key Laboratory of Pesticides and Chemical Biology, Ministry of Education, College of Chemistry, Central China Normal University, Wuhan, Hubei 430079, P. R. China.
Hongying
H
Zhong
D002384:Catalysis / Q000528:radiation effects; D004579:Electron Transport; D007834:Lasers; D008422:Materials Testing / Q000379:methods; D053758:Nanoparticles / Q000737:chemistry* / Q000528:radiation effects* / Q000648:ultrastructure; D010777:Photochemistry / Q000379:methods; D010937:Plant Growth Regulators / Q000737:chemistry* / Q000528:radiation effects*; D012666:Semiconductors
D010937:Plant Growth Regulators