Constructing Crystalline g‐C 3 N 4 /g‐C 3 N 4−x S x Isotype Heterostructure for Efficient Photocatalytic and Piezocatalytic Performances
Constructing Crystalline g‐C 3 N 4 /g‐C 3 N 4−x S x Isotype Heterostructure for Efficient Photocatalytic and Piezocatalytic Performances
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构建晶体 g–C 3 N 4 /g–C 3 N 4–x S x 同型异质结构以实现高效的光催化和压电催化性能
DOI：
10.1002/eem2.12306
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发表时间：
2022
期刊：
影响因子：
--
通讯作者：
Li Li
中科院分区：
文献类型：
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作者：
Tingting Xu;Zhonghui Xia;Hongguan Li;Ping Niu;Shulan Wang;Li Li
石墨化碳氮化物(g-C3N4)具有加工温度低、化学稳定性高等优点，被认为是一种具有工业化应用前景的可见光催化剂。然而，在富氮前驱体直接焙烧过程中，由于不完全聚合导致严重的电荷复合，严重限制了其光催化性能。为了促进电荷分离，我们提出了一种合理的策略，即通过熔盐法构建晶态g-C3N4/g-C3N4−xSx异质结。理论计算表明，在异质结中，g-C3N4和S掺杂的g-C3N4层之间形成了明显的电荷转移通道。由于g-C3N4/g-C3N4−xSx具有较高的结晶度以减少电荷复合和同型异质结构可有效地进行电荷转移，因此具有显著的光催化性能，产氢速率最高可提高12.3倍。这项工作的另一个新奇之处是，我们首次通过表征晶态g-C3N4对H_2O_2生成和KMnO_4还原的性能来考察其压电催化活性。值得注意的是，通过NaBH4处理可以进一步提高g-C3N4的压电催化性能，这是通过引入额外的氰基和去除三S-三氮杂层结构中的部分NHx物种来增强晶态g-C3N4的不对称结构。这项工作为设计高效的聚合物光催化剂开辟了新的策略，并突出了g-C3N4的压敏催化研究。
Graphitic carbon nitride (g‐C3N4) is viewed as a promising visible‐light photocatalyst for industrialization due to its low processing temperature and high chemical stability. However, serious charge recombination caused by incomplete polymerization during direct calcination of nitrogen‐rich precursors significantly limits its photocatalytic performances. To boost charge separation, herein, we propose a rational strategy by constructing a crystalline g‐C3N4/g‐C3N4−xSxisotype heterostructure through the molten salt method. Theoretical calculation reveals that apparent charge‐transfer channels are formed between g‐C3N4and S‐doped g‐C3N4layers in the heterostructure. Owing to high crystallinity for decreasing charge recombination and isotype heterostructure for efficient charge transfer, the as‐prepared g‐C3N4/g‐C3N4−xSxshowed remarkable photocatalytic performances with the hydrogen production rate elevated by up to 12.3 times of its singular components. Another novelty of this work is we investigated for the first time the piezocatalytic activity of crystalline g‐C3N4by characterizing its performance for H2O2generation and KMnO4reduction. Strikingly, its superior piezocatalytic performance over components can be further improved by NaBH4treatment, which is uncovered to enhance the asymmetric structure of crystalline g‐C3N4by introducing extra cyano groups and removing partial NHxspecies in its tri‐s‐triazine layer structure. This work opens up new strategies for the design of highly efficient polymeric photocatalysts and highlights the piezocatalytic studies of g‐C3N4.