Dual-Functional Copper Metal–Organic Frameworks through Reversible Valence Transformation for Self-Powered Photocatalytic Detoxification of a Sulfur Mustard Simulant

The design and fabrication of dual-function molecular materials that integrate triboelectric performance with photocatalytic activity represent a promising method to achieve selective self-powered detoxification of chemical warfare agents (CWAs). Herein, we developed a feasible and controllable strategy for the same by coalescing isomorphic metal-organic frameworks (MOFs) with different central metal valence states as photocatalysts and triboelectric layers to construct a self-powered photocatalytic detoxification system with triboelectric nanogenerators (TENGs) as a power source. An anionic framework Cu^I-MOF (<b>1</b>) underwent a reversible valence conversion, forming a topologically equivalent isomorphic and neutral mixed-valent framework Cu^ICu^II-MOF (<b>2</b>) via a single-crystal-to-single-crystal (SC-SC) redox process. <b>1</b>-TENG exhibited higher outputs than <b>2</b>-TENG. Considering the reversible valence change and atmospheric responsiveness of the two frameworks, the outputs of the respective TENGs were evaluated under different atmospheric conditions. The outputs of <b>1</b>-TENG were significantly influenced by the atmospheric conditions, decreasing as the oxygen (O₂) concentration gradually increased, while those of <b>2</b>-TENG remained unchanged. Notably, the maximal output of <b>1</b>-TENG exhibited outstanding durability, enabling it to power white light-emitting diodes (LEDs) directly. These LEDs served as the visible-light source to promote the photocatalytic degradation of the sulfur mustard simulant 2-chloroethyl ethyl sulfide, using <b>1</b> as the photocatalyst.