抗污型CFC/TiO_(2)光热织物的制备及其在海水淡化中的应用

Preparation of anti-fouling CFC/TiO_(2) photothermal fabric and its application in seawater desalination

太阳能光热海水蒸发被认为是解决淡水危机的有效策略,但实际海水中存在油污和有机污染物,长期蒸发过程中污染物会黏附在光热膜表面,致使膜的蒸发性能下降。为实现海水的长期抗污型蒸发,制备兼具光热和光催化性能的碳纤维布(CFC)/TiO_(2)织物。以CFC为衬底,通过水热法在其表面生长TiO_(2)纳米棒阵列(TiO_(2)纳米棒直径约为0.47μm、长度约为1.49μm)。结果显示:CFC/TiO_(2)织物表现出超亲水和超疏油特性,同时具有宽光谱(280~2500nm)光吸收性能(光吸收效率约为88%);在模拟太阳光激发下,CFC/TiO_(2)还可光催化降解有机污染物,如在200min内降解73%的盐酸四环素。将CFC/TiO_(2)光热薄膜构筑成倾斜式海水蒸发器,在模拟阳光(光强为1kW/m^(2))照射下,部分海水被蒸发,蒸发速率达1.68kg/(m^(2)·h),浓缩后的海水在织物底端滴落,长期蒸发不析盐。这种光热/光催化织物有望推动太阳能海水淡化走向实际应用。

Solar-driven seawater evaporation has been considered an effective strategy to solve the freshwater crisis,but natural seawater contains oil and organic contaminants that adhere easily to photothermal film during long-term evaporation,thus deteriorating the evaporation performance.To achieve long-term anti-fouling evaporation,we reported the construction of TiO_(2)-coated carbon fiber cloth(CFC)with photothermal/photocatalytic features.TiO_(2) nanorods(diameter:~0.47μm,length:~1.49μm)were in-situ grown on CFC(as substrate material)surface by a hydrothermal method.CFC/TiO_(2) fabric shows super-hydrophilic and super-oleophobic performance,and it displays a strong photoabsorption in a wide range(280 to 2500 nm)with an absorption efficiency of 88%.CFC/TiO_(2) also exhibits photocatalytic activity toward organic pollutants under simulated sunlight,for instance,73%of tetracycline hydrochloride(TC)could be degraded within 200 min.Subsequently,CFC/TiO_(2) is hanging between the seawater tank and the empty tank to form a hanging-model evaporator.Under simulated sunlight(1 kW/m^(2))irradiation,part of the seawater can be evaporated at a high rate of 1.68 kg/(m^(2)·h),while the concentrated seawater can drip from the fabric bottom,avoiding solid-salt crystallization during long-term evaporation.Therefore,the photothermal/photocatalytic fabric has the potential to promote solar desalination towards practical applications.