Ferroelectric materials as photoelectrocatalysts: photoelectrode design rationale and strategies

Abstract

Ferroelectrics are crystalline materials that possess a permanent and reversible spontaneous polarization. When applied in (opto)electronic devices, the presence of a polarization-induced internal electric field can facilitate enhanced charge separation and transport. Changing the polarization state additionally alters the electronic states and surface properties of ferroelectrics, which can be exploited to gain better control over reaction activity and selectivity when ferroelectrics are used as catalysts. For these reasons, ferroelectrics offer significant potential as new generation photoelectrodes. Given the growing interest in their use for photoelectrochemical applications, it is timely to thoroughly review the intricate interplay between ferroelectric properties and photoelectrochemical performance. The focus of this review article is to provide such a comprehensive background. We cover the design strategies used thus far for ferroelectric-based photoelectrodes through microstructure tuning, thin film configuration control, and chemical modification by introducing defects and dopants, with a particular focus on factors that impact photoelectrochemical performance. Experimental design considerations for ferroelectric photoelectrodes, including material fabrication, poling methods, and electrolyte selection, which play important roles in ferroelectric-based photoelectrochemical systems, are also highlighted. Ultimately, this review is expected to set the stage for innovative breakthroughs in the design and synthesis of high-performing ferroelectric-based photoelectrodes for sustainable solar fuel and chemical generation.