Abstract The novel Z-scheme heterojunction photocatalyst g-C3N4/Ag2S/SnS2 with Ag2S quantum dots as electron mediators was successfully synthesized by in-situ ion exchange reaction and self-peeling of g-C3N4. Compared with g-C3N4, SnS2 or g-C3N4/SnS2, the photocatalyst g-C3N4/Ag2S/SnS2 exhibited more excellent photocatalytic performance under visible light irradiation. The removal rate of methyl orange was 96.8% after 30 minutes visible light irradiation and the reaction rate constant reached 0.10225 min-1. The enhanced photocatalytic activity could be attributed to the formation of Z-scheme heterojunction structure and the 2D layered structure. The electrochemical and photoelectric performance tests showed that the separation and transfer efficiency of the photogenic electron-hole pairs as well as the redox potential were significantly improved. Additionally, the quenching experiments showed that the superoxide radicals and holes were the primarily active species. Combined with other characterizations, the reaction mechanism of the g-C3N4/Ag2S/SnS2 for degrading the target pollutant methyl orange under visible light irradiation was proposed.

中文翻译：

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在 SnS2/g-C3N4 纳米片复合材料中沉积 Ag2S 量子点作为电子介体以构建具有增强光催化性能的 Z 型异质结

摘要 通过原位离子交换反应和g-C3N4的自剥离，成功合成了以Ag2S量子点为电子介体的新型Z型异质结光催化剂g-C3N4/Ag2S/SnS2。与g-C3N4、SnS2或g-C3N4/SnS2相比，g-C3N4/Ag2S/SnS2光催化剂在可见光照射下表现出更优异的光催化性能。可见光照射30分钟后甲基橙去除率为96.8%，反应速率常数达到0.10225 min-1。增强的光催化活性可归因于 Z 型异质结结构和二维层状结构的形成。电化学和光电性能测试表明，光生电子-空穴对的分离和转移效率以及氧化还原电位均显着提高。此外，淬火实验表明超氧自由基和空穴是主要的活性物质。结合其他表征，提出了g-C3N4/Ag2S/SnS2在可见光照射下降解目标污染物甲基橙的反应机理。