XPS studies of View the MathML source and View the MathML source systems

The detailed analysis of the experimental XPS envelopes of the model View the MathML source and View the MathML source systems was performed using a curve fitting procedure. It appeared possible to fit the XPS spectrum of View the MathML source system with a single View the MathML source doublet which indicates the presence of only one type of molybdenum(VI) oxo-species In contrast, curve fitting for View the MathML source system required two individual View the MathML source doublets. The first View the MathML source doublet with the binding energy close to that of bulk MoO3 was attributed reflects the to three-dimensional molybdenum(VI) oxo-species. The second View the MathML source doublet, shifted to higher binding energy, presence of monomeric or two-dimensional molybdenum(VI) oxo-species which strongly interact with silica surface.