Hybrid Photoelectrodes Based on Electropolymerized Conjugated Porous Polymers for Enhanced Solar Energy Conversion

This work highlights and offers fundamental insights on the potential of electropolymerized conjugated porous polymers in developing efficient hybrid photoelectrodes for photoelectrochemical applications. A simple and cost-effective electropolymerization strategy to create hybrid organic-inorganic photoelectrodes based on two thiophene-based conjugated porous polymers (CPP-3TB and IEP-19) for enhanced solar energy conversion is used. These polymers, when integrated with TiO₂ to form hybrid photoanodes, exhibit enhanced photopotentials and photocurrents compared to bare TiO₂. This synergetic behavior is attributed to an increased visible light absorption, reduced charge transfer resistance, and minimized electron-hole recombination. In particular, detailed electrochemical and spectroscopic analyses, including electrochemical impedance spectroscopy and transient absorption spectroscopy, reveal that the hybrid systems' superior charge transport and longer photogenerated charge lifetimes contribute to their increased efficiency in solar energy conversion. Moreover, by comparing the structure and behavior of both hybrid systems, corner stone knowledge for the synthesis of CPPs to guide the construction of the future photoelectrochemical cells for solar energy conversion is offered.