Visible‐Light‐Active Mixed‐Valent Copper‐Ion‐Coordinated 2,5‐Dimercapto‐1,3,4‐thiadiazole‐Based p‐Type Metallopolymer

Abstract

AbstractVisible‐light‐active coordination metallopolymer and metal‐organic frameworks have gained substantial attention in recent years, owing to their tunable electronic properties. Herein, we present a novel copper‐ion‐containing metallopolymer, which exhibits visible‐light absorption and p‐type photoelectrochemical behavior. The functional thiadiazole‐based metallopolymer thin films were prepared by using both chemical and electrochemical methods on fluorine‐doped tin oxide substrates. XPS, Raman, and FTIR spectral investigations evidence the presence of Cu(II), Cu(I), Cu−S, and disulfide (S−S)2− linkages in the polymeric network. The swift photoresponses, repeatable photovoltage of approximately 55 mV with zero applied current, and high photocurrent values at different bias potentials (ca. 24 μA cm−2 @ −0.6 V vs. Ag/AgCl in 0.1 KCl) in acidic electrolytes (0.5 M H2SO4) suggest that this metallopolymer as an acid‐stable p‐type photocathode material. In contrast, the electropolymerized non‐metallated polymers exhibit n‐type photoactivity. Photoelectrochemical sensing studies reveal the analyte‐induced reduction in photoactivity.