Chinese Journal of Catalysis ›› 2020, Vol. 41 ›› Issue (10): 1589-1602.DOI: 10.1016/S1872-2067(20)63555-0

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Synthesis of Ni2+ cation modified TS-1 molecular sieve nanosheets as effective photocatalysts for alcohol oxidation and pollutant degradation

Imran Khana, Xiaoyu Chua,b, Yanduo Liua, Salman Khanc, Linlu Baia,b, Liqiang Jinga   

  1. a Department Key Laboratory of Functional Inorganic Materials Chemistry, Ministry of Education, School of Chemistry and Materials Science, International Joint Research Center and Lab for Catalytic Technology, Heilongjiang University, Harbin 150080, Heilongjiang, China;
    b School of Chemical and Environmental Engineering, Harbin University of Science and Technology, Harbin 150080, Heilongjiang, China;
    c State Key Laboratory of Fine Chemicals, School of Chemical Engineering, Dalian University of Technology, Dalian 116024, Liaoning, China
  • Received:2020-02-23 Revised:2020-03-29 Online:2020-10-18 Published:2020-08-15
  • Supported by:
    This work was supported by the National Natural Science Foundation of China (U1805255, 21706044), the Research Project of Chinese Ministry of Education (213011A), the China Postdoctoral Science Foundation (2017M621316), the Natural Science Foundation of Heilongjiang Province, China (B2017006), and the Postdoctoral Science Foundation of Heilongjiang Province, China (LBH-Z17187).

Abstract: Improvement of the charge separation of titanosilicate molecular sieves is critical to their use as photocatalysts for oxidative organic transformations. In this work, MFI TS-1 molecular sieve nanosheets (TS-1 NS) were synthesized by a low-temperature hydrothermal method using a tailored diquaternary ammonium surfactant as the structure-directing agent. Introducing Ni2+ cations at the ion-exchange sites of the TS-1 NS framework signi?cantly enhanced its photoactivity in aerobic alcohol oxidation. The optimized Ni cation-functionalized TS-1 NS (Ni/TS-1 NS) provide impressive photoactivity, with a benzyl alcohol (BA) conversion of 78.9% and benzyl aldehyde (BAD) selectivity of 98.8% using O2 as the only oxidant under full light irradiation; this BAD yield is approximately six times greater than that obtained for bulk TS-1, and is maintained for five runs. The excellent photoactivity of Ni/TS-1 NS is attributed to the significantly enlarged surface area of the two-dimensional morphology TS-1 NS, extra mesopores, and greatly improved charge separation. Compared with bulk TS-1, Ni/TS-1 NS has a much shorter charge transfer distance. The as-introduced Ni species could capture the photoelectrons to further improve the charge separation. This work opens the way to a class of highly selective, robust, and low-cost titanosilicate molecular sieve-based photocatalysts with industrial potential for selective oxidative transformations and pollutant degradation.

Key words: TS-1 nanosheet, Photocatalytic alcohol oxidation, Charge separation, Ni species as electron capturer, O2 activation