Piezopolarization-Steered Photocatalytic and Electrocatalytic CO ₂ Conversion: A Comprehensive Review

High Resolution Image Download MS PowerPoint Slide Piezopolarization has emerged as a transformative strategy to overcome the fundamental kinetic and thermodynamic limitations of photocatalytic and electrocatalytic CO 2 reduction. Piezoelectric and ferroelectric materials undergo mechanical deformation to generate powerful internal polarization fields to adjust band structures, induce directional carrier migration, and change the adsorption energetics of key intermediates. These polarization-mediated fields, in combination with photoexcitation or external electrochemical bias, boost charge separation, accelerate interfacial electron transfer, and selectively reduce the activation barriers of multielectron CO 2 conversion pathways and reduce competing hydrogen evolution. This review offers an in-depth assessment of piezopolarization-assisted CO 2 conversion: its foundational concepts, material innovations, and device engineering strategies. Theoretical and computational insights are of particular interest, where the reorientation of polarization-induced dipoles through strain changes the positions of band edges and potential energy surfaces and stabilizes intermediates, including, but not limited to, those formed by the reaction of *COOH, *OCHO, and *CHO. These theoretical results yield mechanistic support of polarization-controlled reaction energetics and rationalize experimental trends in piezophotocatalytic, piezo-assisted electrocatalytic, and piezophotoelectrocatalytic CO 2 reduction systems. The review closes by describing ongoing challenges and opportunities, such as flexoelectric coupling, engineering domain-level polarization, self-powered architectures, and AI-guided catalyst discovery, to facilitate scalable, high-efficiency CO 2 to chemical conversion via mechanical stimuli. In a synthesis of experimental and theoretical viewpoints, this Review brings into limelight the concept of piezopolarization as a new paradigm for next-generation carbon-neutral energy technologies.