Large photocurrent generation of an ITO electrode modified with a red copper(II) complex

A film of copper complex [CuL](NO3)2 (L = 2,3,8,9-tetraphenyl-1,4,7,10-tetraazacyclododeca-1,3,7,9-tetraene) formed on indium–tin oxide (ITO) coated glass by the solvent evaporation of the acetonitrile solution of the complex onto the ITO substrate, was characterized by ultraviolet-visible absorption spectroscopy, cyclic voltammetry, scanning electron microscopy, and photoelectrochemistry. The photoelectrochemical cell by using [CuL](NO3)2 modified ITO, a saturated calomel electrode, and platinum wire as working, reference and counter electrodes respectively in 1 M Na2SO4, was found to exhibit a large prompt and reproducible cathodic photocurrent density of 71 μA/cm2 under white light irradiation of 70 mW/cm2 at an applied potential of −0.4 V, and an incident photon to current efficiency (IPCE) of 1.1% at λ = 660 nm. This Cu(II) complex photosensitizer has advantages of simple synthesis, low-cost, environmentally benign and good photoelectrochemical performance.

Figure optionsDownload full-size imageDownload as PowerPoint slideHighlights► Copper complex for solar energy photoelectric conversion. ► Cathodic photocurrent density of 71 μA/cm2 under white light irradiation of 70 mW/cm2. ► An incident photon to current efficiency of 1.1% at λ = 660 nm.