Influence of Adsorption of para-Aminothiophenol on Trap States and Recombination Kinetics at Plasmonic Ag-TiO2 Heterostructure Interfaces

The variation of trap states and the involving kinetics on the Ag-TiO2 interfaces after the adsorption of reactant molecules were explored with the help of the combination of spectroscopic, electrochemical and photoelectrochemical methods by using para-aminothiophenol (PATP) as a probe molecule. The results of photoluminescence spectroscopy and chronoamperometry revealed the distribution of trap states of Ag-TiO2 heterostructures and the influence of PATP's adsorption. Kinetic measurements of open-circuit photovoltage showed that the adsorption of PATP affects not only the electron lifetime (tau(n)) but also the recombination mechanism of charge-carrier on Ag-TiO2 heterostructures. The analysis of the obtained effective recombination orders indicated that the charge-carrier recombination on the Ag-TiO2 electrode followed second-order kinetics, while the one of the Ag-TiO2/PATP electrode evolved from first-order kinetics at first (at higher V-oc) to second-order kinetics (at lower V-oc).

Automated summary

Through the combination of spectroscopic, electrochemical, and photoelectrochemical methods, the variation of trap states and kinetics on the Ag-TiO2 interfaces after the adsorption of reactant molecules was investigated using para-aminothiophenol (PATP) as a probe molecule. Results from photoluminescence spectroscopy and chronoamperometry revealed the distribution of trap states and the influence of PATP's adsorption on Ag-TiO2 heterostructures. Kinetic measurements of open-circuit photovoltage showed that PATP adsorption affects the electron lifetime and recombination mechanism of charge carriers on Ag-TiO2 heterostructures.