Xiong Peiyao, Li Qian, Tang Qijun, Wang Haiqiang, Wu Zhongbiao
Key Laboratory of Environment Remediation and Ecological Health, Ministry of Education, College of Environmental & Resources Science, Zhejiang University Hangzhou 310058 P. R. China
Zhejiang Tianlan Environmental Protection Technology Co., Ltd, Zhejiang Provincial Engineering Research Center of Industrial Boiler & Furnace Flue Gas Pollution Control Hangzhou 311202 P. R. China.
RSC Adv. 2023 Oct 30;13(45):31820-31834. doi: 10.1039/d3ra06066g. eCollection 2023 Oct 26.
In this study, alkali-metal-doped crystalline g-CN with an enriched cyano group was synthesized using the molten salt method and used for the visible-light photocatalytic degradation of methylamine (MA), a common organic amine compound with a low odor threshold. Different types and proportions of melting salts (Li, K, and Na) were added during secondary calcination to regulate the morphology, crystallinity, and surface defects of graphitic carbon nitride (g-CN). With molten salt treatment matched the melting point of the binary salt system, a cyano group and alkali metal co-doped crystalline g-CN with a high surface area and good crystallinity were prepared. Co-decorating the alkali metal and cyano groups on crystalline g-CN facilitated the adsorption of MA, realized an excellent photo-charge transfer efficiency, and generated more superoxide radicals. Compared with pristine g-CN (PCN), the apparent rate constant of LiK15 : 5-CCN for the degradation of MA increased by 10.2 times and the degradation efficiency of 1000 ppm MA gas was 93.1% after 90 min of irradiation with visible light, whereas the degradation efficiency of PCN was 19.2%.
在本研究中，采用熔盐法合成了富含氰基的碱金属掺杂结晶性g-CN，并将其用于甲胺（MA）的可见光光催化降解，甲胺是一种常见的有机胺化合物，气味阈值较低。在二次煅烧过程中添加不同类型和比例的熔盐（Li、K和Na），以调节石墨相氮化碳（g-CN）的形貌、结晶度和表面缺陷。通过与二元盐体系熔点相匹配的熔盐处理，制备了具有高比表面积和良好结晶度的氰基和碱金属共掺杂结晶性g-CN。在结晶性g-CN上共修饰碱金属和氰基促进了MA的吸附，实现了优异的光电荷转移效率，并产生了更多的超氧自由基。与原始g-CN（PCN）相比，LiK15 : 5-CCN降解MA的表观速率常数提高了10.2倍，在可见光照射90分钟后，1000 ppm MA气体的降解效率为93.1%，而PCN的降解效率为19.2%。
