螺吡喃功能化UiO-66光响应吸附剂的制备及其性能

Photo‑responsive UiO‑66 with spiropyran functionalization adsorbent:Preparation and adsorption performance

将光响应分子甲基螺吡喃SP-CH_(3)引入UiO-66的非极性孔笼中,构筑吸附活性位可光控调节的光响应吸附剂。SP-CH_(3)功能化的吸附剂完好保留了载体UiO-66的骨架和孔道结构。以阴离子染料甲基橙为探针,研究了吸附剂在不同光照条件下的吸附和解吸性能。结果表明,经紫外光照后,吸附剂对甲基橙的吸附量为41.99 mg·g^(-1),相较于可见光照后样品的吸附量提升57.56%,吸附作用增强;经可见光照后,甲基橙的脱附量为81.6%。本策略通过光照刺激改变UiO-66孔笼中SP-CH3的构型及表面电荷性质,即对吸附活性位进行光控调节,在不同光照条件下实现对吸附质的高效吸附和有效脱附。

Herein,a representative metal-organic framework(MOF),UiO-66,with a microporous structure and hydrothermal stability,has been chosen as porous support.Photo-responsive adsorbents were prepared by introduc-ing the spiropyran derivative SP-CH3 into the non-polar pore cage of UiO-66 as photo-regulated active sites.The framework structure of the support material was maintained after SP-CH_(3) functionalization.An anionic dye,methyl orange,was adopted as a probe to explore the adsorption and desorption performance of the adsorbent in different light conditions.The experimental results showed that the adsorption amount of methyl orange by the sample after UV irradiation was 41.99 mg·g^(-1),which increased by 57.56%in comparison to that after visible light irradiation.In addition,the desorption of methyl orange of the adsorbent after visible light irradiation was up to 81.6%.Changes in the electric surface charge and polarity of the adsorbents,owing to efficient photo-isomerization of spiropyran in the non-polar environment of UiO-66 cage,have great effects on the adsorption/desorption behaviors of methyl orange on the adsorbents.The resultant adsorbents with photo-regulated active sites exhibit enhanced adsorptive perfor-mance and effective desorption.