Liu Y, Zhang Y Y, Kou Q W, Chen Y, Han D L, Wang D D, Lu Z Y, Chen L, Yang J H, Xing S
College of Physics, Jilin Normal University Siping 136000 China
Key Laboratory of Functional Materials Physics and Chemistry of the Ministry of Education, Jilin Normal University Changchun 130103 China.
RSC Adv. 2018 Jan 9;8(4):2209-2218. doi: 10.1039/c7ra11348j. eCollection 2018 Jan 5.
Hybrid FeO-Ag nanocrystals, a new type of highly efficient and reusable catalyst for methylene blue (MB) reduction, are fabricated by a novel seed deposition process. X-ray diffraction and Mössbauer spectroscopy results show that the developed iron oxides are in a pure magnetite FeO phase. Upon manipulating the amount of Ag seeds capsuled on the modified surfaces of FeO nanocrystals, the catalytic capacities on the reduction of MB can be precisely adjusted with a tunable fabrication cost control. The linear correlation of the reduced MB concentration reaction time catalyzed by our developed hybrid FeO-Ag nanocrystals is coherent with pseudo first order kinetics. Importantly, with remarkable recyclability features, the hybrid FeO-Ag nanocrystals can be easily separated by applying an external magnetic field. The tailored catalytic performances of the hybrid FeO-Ag nanocrystals during MB reduction are attributed to the optimized dynamic electron transfer process, which dominates the electrochemical mechanism wherein the nucleophilic BH ions donate electrons to electrophilic organic MB through Ag seeds in a regulated amount. Such developed hybrid FeO-Ag nanocrystals pave the way towards the mass production of highly efficient and low cost catalysts for methylene blue reduction.
通过一种新型的种子沉积工艺制备了一种用于亚甲基蓝（MB）还原的新型高效可重复使用催化剂——杂化FeO-Ag纳米晶体。X射线衍射和穆斯堡尔光谱结果表明，所制备的铁氧化物为纯磁铁矿FeO相。通过控制包裹在FeO纳米晶体改性表面上的Ag种子的数量，可以精确调节MB还原的催化能力，并实现可调的制造成本控制。我们所制备的杂化FeO-Ag纳米晶体催化还原MB的浓度与反应时间的线性相关性符合准一级动力学。重要的是，杂化FeO-Ag纳米晶体具有显著的可回收性，通过施加外部磁场可以轻松分离。杂化FeO-Ag纳米晶体在MB还原过程中定制的催化性能归因于优化的动态电子转移过程，该过程主导了电化学机制，其中亲核BH离子通过Ag种子以规定的量向亲电有机MB提供电子。这种所制备的杂化FeO-Ag纳米晶体为大规模生产用于亚甲基蓝还原的高效低成本催化剂铺平了道路。
