Energy-Responsive Nb2C 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 Nb2C 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.