Extended Framework Semiconductors (EFSs): A Unique and Efficient Platform for Synergetic Piezo‐Photocatalysis

Abstract

Piezo‐photocatalysis is a compelling solution to synergistically merge their respective advantages. However, research on piezo‐photocatalysis has focused on inorganic semiconductors recently. Some studies and reviews have demonstrated the potential of organic semiconductor‐based materials, but these efforts remain fragmented due to the absence of a unified classification. Here, we introduce a unifying concept, extended framework semiconductors (EFSs), to categorize a broad family of 2D or 3D periodic networks constructed via covalent, coordination, or hydrogen bonding interactions. This family includes crystalline carbon nitrides (polyheptazine imide (PHI) and polytriazine imide (PTI)), semicrystalline graphitic carbon nitride (g‐C 3 N 4 , C 3 N 5 ), covalent organic frameworks (COFs), metal–organic frameworks (MOFs), and hydrogen‐bonded organic frameworks (HOFs). EFSs uniquely combine tunable specific surface area, facile functionalization, controllable structural dynamics (flexibility in MOFs/COFs/HOFs and interlayer adaptability in layered carbon nitrides), and band structure tailorability, making them ideal platforms for piezo‐photocatalysis. This review systematically summarizes the research progress of EFSs‐based piezo‐photocatalysts, with an emphasis on their distinct advantages over conventional inorganics. We further outline design strategies including defect engineering, morphology regulation, noble‐metal modification, functional group introduction, and heterojunction construction, along with the underlying mechanisms for enhanced catalytic performance. Finally, we discuss current challenges and future prospects, charting a clear roadmap for the development of high‐efficiency EFSs‐based piezo‐photocatalysts.