Preparation Of Ag/N-TiO₂ Nanoarrays For Surface Plasmon-driven Coupling Reactions

Surface enhanced Raman spectroscopy has long been thought as a non-destructive testing technology. However, in recent years, it found that the Raman spectrum of target molecules would produce some new Raman fingerprint peaks under the effect of laser in the study of the detection. Under the SERS condition, the nitrobenzene thiophenol attached on the silver nanoparticles can produce coupling reaction generated azobenzene, such reactions is called the plasmon-driven catalytic reactions. Current research on semiconductor-metal nanocomposites are mostly the use of metal surface plasmon to enhance the photocatalytic properties of the semiconductor. It is the difficulty in present study if we can use the surface plasma characteristics of the semiconductor-metal composite material to achieve some other chemical reactions, and to find what role of semiconductor in these reactions.In this paper the Ti O2 nanoarrays growth on FTO glass by the method of hydrothermal, and the growth conditions are determined by adjusting the reaction time, also, the silver particles growth on the surface of Ti O 2 nanoarrays by using the method of sensitization, and then explored th e silver particle size and distribution under the conditions of different silver saurce, reducing agent, concentration and reaction time.The surface morphology was observed mainly by means of SEM and TEM, with its crystal shape was characterized by XRD and XPS confirms the nitrogen element doping in the basal surface in the form of N-Ti bond. Meanwhile, this work explored the influence of silver particle distribution situation to Raman signal intensity of the 4MBA molecule with modifed and before modified substrates. It found that it would have the strongest Raman response signal when soaking time for 20 min in the silver source with 10-5 mol/L 4MBA solution. Under the Raman two substrates for the signal detection of trace molecular R6 G can reach 10-9 mol/L and 10-7 mol/L respectively.In the study of surface plasmon catalytic reaction, it found that under visible light irradiation, SP can pass electrons to the p-nitrophenol thiophenol, which generated in substrate, and then p-nitrophenol thiophenol were reduced to azobenzene. And surface plasmon can also activate oxygen in the air, which makes the amino thiophenol generate azobemzene coupling reaction happen. It is important that the study found that the surface plasmon induced chemical reaction in the semiconductor-metal nanocomposites, the reaction rather faster than in the pure metal substrate. The plasmon-driven catalytic reactions in semiconductor-metal nanocomposites research is expected to widen the scope of the research of this field.