Atomic Pt and molecular H₂O adsorptions on SrTiO₃ with and without Nb-doping: Electron trapping center and mediating roles of Pt in charge transfer from semiconductor to water

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• 作者：Wei Wei ; Ying Dai ; ^{daiy60@sina.com} ; Meng Guo ; Yandong Ma ; Baibiao Huang
• 关键词：SrTiO3 (0  ; 0  ; 1) surface ; Pt adsorption ; H2O adsorption ; Charge transfer ; DFT calculation
• 刊名：Journal of Solid State Chemistry
• 出版年：2012
• 出版时间：March 2012
• 年：2012
• 卷：187
• 期：Complete
• 页码：64-69
• 全文大小：589 K

文摘

H₂O adsorption on SrO-terminated SrTiO₃ (0 0 1) surface has been investigated with the first-principles calculation based on DFT. An energy barrier of 0.221 eV for H₂O dissociation is obtained, which illustrates a spontaneous dissociation. H and O atoms on the SrO-termination of (0 0 1) surface recombine readily. It demonstrates that Pt induces surface dipole moment and changes the surface work function. Adsorption of atomic Pt on SrO-termination of Nb-doped SrTiO₃ (0 0 1) surface indicates charge transfer from the surface to Pt, i.e., Pt is negatively charged. Fukui functions illustrate the role Pt played in mediating charge transfer from (0 0 1) surface to targets adsorbed on Pt. H₂O adsorption on the Pt atom supported on Nb-doped SrTiO₃ confirms the charge transfer from semiconductor containing electrons to target species, which is mediated by metal. Charge transfer from negatively charged Pt to H₂O weakens (activates) the H-O bonds in molecule H₂O.