本研究以水熱法合成氧化銫鎢/石墨型碳氮化物(Cs0.33WO3@g-C3N4)複合材料，並將其與疏水聚氨酯(PU)均勻混合後，塗佈於聚對苯二甲酸乙二醇酯(PET)不織布基材上，並採用相轉換法形成多孔結構。而後，於不織布另一側塗佈親水PU以形成具有相反潤濕性的親/疏水複合膜。在本研究中，親/疏水複合膜的底層為親水PU，可將污水從底部送到上層受熱蒸發；由光熱材料組成的疏水側則作為頂層，可吸收全波長太陽光並將其轉化為熱能。由於多孔結構產生的多重散射，增加了材料的吸光度，並幫助水氣迅速蒸散。其中，20 wt%光熱材料製成的親/疏水複合膜在1個太陽光照下可迅速升溫至98℃，且展現76%的水蒸發效率。另外在染料降解亦達到約96.7%的高移除率，提升了此膜的應用性。此外，親/疏水複合膜的製程工法具有可擴展性，可用於大規模生產，這對於環境議題，如：水汽蒸發、海水淡化、表面光催化及污水處理等實際應用上有重大的影響。

In this work, cesium tungsten oxide/graphitic carbon nitride (Cs0.33WO3@g-C3N4) hybrids synthesized by the solvothermal method was immobilized into hydrophobic polyurethane (PU) and coated onto polyethylene terephthalate (PET) nonwoven fabric substrate, and the bottom side of the PET was coated with hydrophilic PU to develop Janus membrane with opposite wettability. The porous PU was synthesized by the phase inversion method. In this design, the hydrophilic side of the Janus membrane is used as the bottom layer to pump polluted water from bulk to evaporative region while the hydrophobic composed of photothermal conversion material is used as a top layer to harvest solar light and convert it to heat. The findings reveal that the Janus membranes exhibited outstanding photothermal conversion and water evaporation properties. In particular, the Janus membrane composed of 20 wt% of Cs0.33WO3@g-C3N4 showed excellent photothermal conversion performance by raising the temperature to 98 °C and also showed 76 % water evaporation efficiency under 1 sun illumination. In addition, in the degradation of dyes, high degradation rates of about 96.7% were achieved, respectively, which improved the applicability of the membrane. These superior properties are attributed to porous polyurethane Janus membrane which enables improved the light absorption of photothermal material by multiple scattering of light through porous structure and help the generated water vapors rapidly escape into the air. Moreover, the method of synthesis of the Janus membrane is scalable and can be used for mass production that is very crucial for real application such as water evaporation, desalination, surface photocatalysis, and sewage treatment in environmental remediation.

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