Effects of potassium ions and platinum cocatalysts on the photocatalytic performance of Poly(Heptazine Imides)
Effects of potassium ions and platinum cocatalysts on the photocatalytic performance of Poly(Heptazine Imides)
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DOI：
10.1016/j.apsusc.2023.158275
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发表时间：
2023-08
影响因子：
6.7
通讯作者：
Xiaoxiao Chen;Xu Cai;Yi Li;Yongfan Zhang;Wei-hui Lin
中科院分区：
文献类型：
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作者：
Xiaoxiao Chen;Xu Cai;Yi Li;Yongfan Zhang;Wei-hui Lin
在高结晶度氮化碳的合成中，碱金属卤化物被用作高温溶剂和结构导向剂，但碱金属离子对材料催化活性的影响尚不清楚。此外，助催化剂的形状和尺寸也显著影响材料的催化活性。因此，我们进行了密度泛函理论计算，揭示了一种名为聚七津亚胺钾(K-PHI)的结晶氮化碳(K-PHI)与负载不同尺寸铂助催化剂的质子交换碳氮化钾(H-PHI)在结构、电子性质、光学性质以及光催化析氢性能方面的差异。结果表明，钾离子在K-PHI中具有聚集电子的作用，钾离子对附近的铂原子具有短程诱导偶极效应，导致这些反应位上的光催化析氢活性略有提高。此外，负载量较大的铂助催化剂比负载量较小的催化剂具有更好的光催化析氢活性。该工作为合理设计高性能金属助催化剂和探索碱金属离子在氮化碳中的官能化提供了理论依据。
In the synthesis of highly crystalline carbon nitride, alkali metal halides are used as high-temperature solvents and structural guiding agents, but the effect of alkali metal ions on the catalytic activity of materials is still unclear. In addition, the shape and size of the cocatalyst also significantly affect the catalytic activity of the material. Therefore, we have carried out the density functional theory calculations to reveal the differences in the structure, electronic, and optical properties, as well as the photocatalytic hydrogen evolution performance of one kind of crystalline carbon nitride called potassium poly(heptazine imide) (K-PHI) and its proton-exchanged counterpart (H-PHI) loaded with different sizes of platinum cocatalysts. The results show that potassium ions have the effect of aggregation electrons in K-PHI, and potassium ions have short-range induced dipole effect on nearby Pt atoms, resulting in slightly better photocatalytic hydrogen evolution activity at these reaction sites. Additionally, Pt cocatalyst with larger load size has better photocatalytic hydrogen evolution activity than small size. This work provides a theoretical basis for the rational design of high-performance metal cocatalysts and exploration of the functionality of alkali metal ions in carbon nitrides.