Keshipour Sajjad, Khezerloo Masoumeh
Department of Nanochemistry, Nanotechnology Research Center, Urmia University Urmia Iran
RSC Adv. 2019 May 31;9(30):17129-17136. doi: 10.1039/c9ra01799b. eCollection 2019 May 29.
Novel hydrophobic cellulose aerogel (CA) supported graphene quantum dots (GQD)/Pd were synthesized with high lipophilicity, superior porosity as well as high catalytic activity. The nanocomposite aerogel was obtained in four steps, including transformation of cotton to CA, a silanization reaction of CA in the presence of TiO nanoparticles to give polysiloxane/TiO nanoparticles supported on CA (ST@CA), a modification of ST@CA with GQD to yield polysiloxane/TiO nanoparticles/graphene quantum dots supported on CA (STG@CA), and finally a deposition of Pd nanoparticles on STG@CA. The synthesized aerogel demonstrated hydrophobicity with a water contact angle of 136.2°. It also exhibited excellent oil/water selective absorption capacity with an oil absorption of up to 79 g g with 134 g g selectivity. Finally, the nanocomposite was used as a heterogeneous catalyst in the oxidation reaction of alcohols, ethylbenzene, and alkenes. High yields, excellent selectivities, green and mild reaction conditions, recyclability and biocompatibility of the catalyst were important features of the reactions.
新型疏水性纤维素气凝胶（CA）负载的石墨烯量子点（GQD）/Pd被合成出来，具有高亲脂性、优异的孔隙率以及高催化活性。该纳米复合气凝胶通过四个步骤制备而成，包括将棉花转化为CA、CA在TiO纳米颗粒存在下进行硅烷化反应以得到负载在CA上的聚硅氧烷/TiO纳米颗粒（ST@CA）、用GQD对ST@CA进行改性以生成负载在CA上的聚硅氧烷/TiO纳米颗粒/石墨烯量子点（STG@CA），最后在STG@CA上沉积Pd纳米颗粒。合成的气凝胶表现出疏水性，水接触角为136.2°。它还展现出优异的油/水选择性吸收能力，吸油率高达79 g/g，选择性为134 g/g。最后，该纳米复合材料被用作醇、乙苯和烯烃氧化反应的多相催化剂。催化剂的高收率、优异选择性、绿色温和的反应条件、可回收性和生物相容性是这些反应的重要特征。
