Investigation of the Photoelectrochemistry of C60 and Its Pyrrolidine Derivatives by Monolayer-Modified SnO2 Electrodes

A monolayer of a C 60 mixture with arachidic acid (1:1) and C 60 -pyrrolidine derivatives [C 60 (C 3 H 6 NR); R = H ( 1 ), C 6 H 5 ( 2 ), o -C 6 H 4 NO 2 ( 3 ), and o -C 6 H 4 NMe 2 ( 4 )] were successfully obtained at the air/water interface and deposited onto solid substrates with transfer ratios of about 0.90 ± 0.05 at 30 mN·m -1 by the Langmuir−Blodgett (LB) technique. The photoelectrochemical investigation of these compounds on SnO 2 electrodes was carried out. The photocurrent was determined under nitrogen atmosphere because oxygen can suppress the photocurrents. Results showed that electrons flow from the electrolyte through LB film to SnO 2 and a chemical energy conversion occurs together with the photoelectric conversion. Positive bias voltage, electron donor, the incident light intensity, and the electron-repulsion groups in the derivatives are beneficial factors for generating higher photocurrent. The quantum yields vary from 0.015 to 0.069 for C 60 and its derivatives 1 − 4 .