College of Environmental Science and Engineering, Yangzhou University, Jiangsu, 225127, China.
College of Environmental Science and Engineering, Yangzhou University, Jiangsu, 225127, China; Joint International Research Laboratory of Agriculture and Agri-Product Safety of Ministry of Education of China, Yangzhou University, Yangzhou, 225127, Jiangsu, China; Jiangsu Collaborative Innovation Center for Solid Organic Waste Resource Utilization, Nanjing, 210095, China.
Chemosphere. 2020 Jan;239:124713. doi: 10.1016/j.chemosphere.2019.124713. Epub 2019 Aug 31.
Ultra-thin layered structures and modified bandgaps are two efficient strategies to increase the photocatalytic performance of various materials for the semiconductor industry. In the present study, we combined both strategies in one material to form carbon-doped graphitic carbon nitride (g-CN) nano-layered structures by the method of melamine thermal condensation, in the presence of different mass ratios of biochar. The characterization showed that the composite with the best ratio retained the g-CN polymeric framework and the bond with g-CN. The biochar was established via π-π stacking interactions and ether bond bridges. The π-conjugated electron systems provided from biochar can elevate charge separation efficiency. The ultra-thin structure also curtailed the distance of photogenerated electrons migrating to the surface and enlarge specific surface area of materials. The presence of carbon narrowed the bandgap and increased light absorption at a wider range of wavelengths of g-CN. The biochar/melamine ratio of 1:15 presented the best performance, 2.8 and 5 times faster than g-CN degradating Rhodamine and Methyl Orange, respectively. Moreover, the catalyst presented a good stability for 4 cycles. In addition to that, biochar from waste biomass can be considered a sustainable, cost-effective, and efficient option to modify g-CN-based photocatalysts.
超薄层结构和改性带隙是提高半导体工业中各种材料光催化性能的两种有效策略。在本研究中，我们通过三聚氰胺热缩聚的方法，在不同质量比的生物炭存在下，将这两种策略结合在一种材料中，形成了掺碳石墨相氮化碳（g-CN）纳米层状结构。表征结果表明，最佳比例的复合材料保留了 g-CN 聚合骨架和与 g-CN 的键合。生物炭是通过 π-π 堆积相互作用和醚键桥建立的。生物炭提供的π共轭电子系统可以提高电荷分离效率。超薄结构还缩短了光生电子迁移到表面的距离，并增大了材料的比表面积。碳的存在缩小了带隙，并增加了 g-CN 在更宽波长范围内的光吸收。在生物炭/三聚氰胺的比例为 1:15 时，其性能最佳，分别比 g-CN 降解罗丹明和甲基橙的速度快 2.8 倍和 5 倍。此外，该催化剂在 4 个循环中表现出良好的稳定性。除此之外，来自废生物质的生物炭可以被认为是一种可持续、具有成本效益和高效的方法来修饰基于 g-CN 的光催化剂。
