Energy‐Responsive Nb 2 C MXene‐Based Superwetting Sponge With Coupled Photothermal‐Electrothermal Heating for Multifunctional Environmental Remediation

Energy‐responsive porous materials capable of on‐demand thermal regulation are highly desirable for controlling interfacial transport in complex environmental systems. Herein, an energy‐responsive superwetting sponge is developed by integrating Nb 2 C MXene with CuO nanostructures and polyaniline within a hierarchical porous framework, followed by low‐surface‐energy modification. The composite exhibits broadband light absorption and electrical conductivity, enabling efficient photothermal and electrothermal conversion. Under solar irradiation and low‐voltage stimulation, rapid and uniform temperature elevation is achieved, and the combined photothermal‐electrothermal mode demonstrates enhanced heating performance compared to individual modes. Meanwhile, the superhydrophobic porous structure and active thermal regulation synergistically delay ice nucleation and growth. As a multifunctional platform, the material also enables effective separation of complex oily emulsions and removal of organic contaminants with excellent recyclability. This work provides a versatile MXene‐based strategy for energy‐adaptive porous materials toward advanced environmental remediation and interfacial transport control.