A wettability-gradient-induced diode (WGID) membrane, engineered with MXene, is presented for passive-evaporative cooling. The membrane, composed of PVDF&PU nanofibers and MXene-engineered polyurethane membranes (PU@MXene), exhibits unidirectional water transport and high emissivity (96.40%) in the MIR range, along with superior thermal conductivity (0.3349 W m⁻¹ K⁻¹). In the "dry" state, it achieves a cooling temperature of 1.5°C, and in the "wet" state, 7.1°C, due to its efficient heat dissipation through radiation and conduction, and evaporation. The membrane's wettability gradient enables controlled moisture transport from the inner hydrophobic side to the outer hydrophilic side, preventing reverse penetration. The design allows for zero-energy-consumption cooling through multiple heat dissipation pathways, including thermal radiation, conduction, and evaporation. The WGID membrane demonstrates superior performance compared to traditional cotton, with enhanced moisture-wicking and passive-evaporative cooling capabilities. The membrane's structure, consisting of a tri-layered design with a hydrophobic layer, a transport layer, and a hydrophilic layer, enables effective moisture transport and heat dissipation. The membrane's performance was validated through various characterization techniques, including SEM, TEM, XRD, and FTIR, confirming its unique properties. The WGID membrane shows excellent resistance to washing and abrasion, making it a promising candidate for thermoregulatory textiles in high-humidity environments. The study highlights the potential of MXene-engineered membranes for advanced passive-evaporative cooling applications.A wettability-gradient-induced diode (WGID) membrane, engineered with MXene, is presented for passive-evaporative cooling. The membrane, composed of PVDF&PU nanofibers and MXene-engineered polyurethane membranes (PU@MXene), exhibits unidirectional water transport and high emissivity (96.40%) in the MIR range, along with superior thermal conductivity (0.3349 W m⁻¹ K⁻¹). In the "dry" state, it achieves a cooling temperature of 1.5°C, and in the "wet" state, 7.1°C, due to its efficient heat dissipation through radiation and conduction, and evaporation. The membrane's wettability gradient enables controlled moisture transport from the inner hydrophobic side to the outer hydrophilic side, preventing reverse penetration. The design allows for zero-energy-consumption cooling through multiple heat dissipation pathways, including thermal radiation, conduction, and evaporation. The WGID membrane demonstrates superior performance compared to traditional cotton, with enhanced moisture-wicking and passive-evaporative cooling capabilities. The membrane's structure, consisting of a tri-layered design with a hydrophobic layer, a transport layer, and a hydrophilic layer, enables effective moisture transport and heat dissipation. The membrane's performance was validated through various characterization techniques, including SEM, TEM, XRD, and FTIR, confirming its unique properties. The WGID membrane shows excellent resistance to washing and abrasion, making it a promising candidate for thermoregulatory textiles in high-humidity environments. The study highlights the potential of MXene-engineered membranes for advanced passive-evaporative cooling applications.