Embedding of stereo molecular scaffold into the planar g-C 3 N 4 nanosheets for efficient photocatalytic hydrogen evolut

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Embedding of stereo molecular scaffold into the planar g-C3N4 nanosheets for efficient photocatalytic hydrogen evolution under ordinary pressure Ling Zhou1,2,3,* , Menglong Sun1,2,3, Jiahui Kou1,2,3, Chunhua Lu1,2,3, Ling Li2,3, Fangshu Zhang2,3, and Zhongzi Xu1,2,3 1

State Key Laboratory of Materials-Oriented Chemical Engineering, College of Materials Science and Engineering, Nanjing Tech University, Nanjing 210009, People’s Republic of China 2 Jiangsu Collaborative Innovation Center for Advanced Inorganic Function Composites, Nanjing Tech University, Nanjing 210009, People’s Republic of China 3 Jiangsu National Synergetic Innovation Center for Advanced Materials (SICAM), Nanjing Tech University, Nanjing 210009, People’s Republic of China

Received: 26 May 2020

ABSTRACT

Accepted: 14 August 2020

Graphitic carbon nitride (g-C3N4), as an organic polymer semiconductor, has been the focus of photocatalysts due to its physical and chemical stability, low cost and non-toxicity. However, pristine g-C3N4 also has many drawbacks, such as small specific surface area and easy recombination of photoexcited carriers, which hampered its practical application. In this work, we first propose a design idea of embedding stereo molecular scaffold into g-C3N4 framework with a facile copolymerization method for better exfoliating g-C3N4 to reach a better photocatalytic hydrogen evolution under ordinary pressure. The stereo molecular scaffold looses the interlayer stacking of bulk g-C3N4, benefitting the exfoliation of g-C3N4. The hydrogen evolution activity of stereo molecular scaffold doped g-C3N4 (AMCN-3-E) is about 7.54 times higher than that of the pristine MCN, which may due to the activated p ? p* and n ? p* electron transitions, creating more electron transition paths and accelerating the separation of photoexcited electrons and holes.

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Handling Editor: Mark Bissett.

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https://doi.org/10.1007/s10853-020-05287-x

J Mater Sci

Introduction Photocatalysts can convert the renewable solar energy into chemical energy, hydrogen, which is a carbon-free fuel with a high energy density, and therefore, attract much attention, as a candidate to solve the energy crisis [1–4]. However, the practical application of traditional photocatalysts is severely hindered by the low utilization rate of solar light and poor quantum yield [5–7]. The exploration of effectively photocatalysts for hydrogen generation is a constant challenge to mankind. g-C3N4 is a visiblelight-responsive polymer semiconductor with the band gap of 2.7 eV [8], owing many excellent properties, such as good chemical and thermodynamic stability, low price and facile preparation [7, 9, 10]. The introduction of g-C3N4 to the field of photocatalysis has aroused wide public concern since it opened a new door for the study of organic photocatalytic semiconductors in spite of the inconspicuous original activity [11]. Over the past years, numerous strateg