在光催化反应中,催化剂合适的能带位置以及紧密的界面效应对其光激发电荷的分离起着至关重要的作用。本文中通过简单的预掺杂和熔盐辅助的两步煅烧法制备了具有局域电子差异且均匀分散的硼掺杂氮化碳和磷掺杂氮化碳(B-CN/P-CN)的同质结。利用XRD、FTIR、XPS、DRS、电化学等对材料的结构性能进行表征。结果表明:B和P的掺杂改变了氮化碳的电子结构,在B-CN和P-CN界面处形成了内建电场,促进光生载流子的定向迁移。模拟降解有机污染物罗丹明B (RhB)的实验结果也表明B-CN/P-CN表现出最好的光催化性能,光照60 min后,RhB的降解率高达97.5%,降解速率常数是纯CN的1.5倍。In the photocatalytic reaction, the proper band alignment and tight interface effect play essential roles in the separation of photoexcited charge of photocatalysts. In this work, B-CN/P-CN homojunction with local electronic differences and uniform dispersion were prepared by a simple pre-doping and molten salt assisted two-step calcination method. XRD, FTIR, XPS, DRS and electrochemistry were used to characterize the structural properties of the materials. The results indicated that the doping of B and P alters the electronic structure of carbon nitride, forming a built-in electric field at the B-CN and P-CN interfaces, promoting the directional migration of photogenerated carriers. The experimental results of simulated degradation of organic pollutants RhB also showed that B-CN/P-CN showed the best photocatalytic performance. After 60 min of illumination, the degradation rate of RhB was up to 97.5%, and the degradation rate constant was 1.5 times that of pure CN.
文章采用有机分子焊接方法,将苝-3,4,9,10-四羧酸二酐(PTCDA)分子通过酰胺键焊接于Ti_(3)CN层间,制备了PTCDA分子焊接插层的Ti_(3)CN(Ti_(3)CN-PTCDA)。PTCDA分子焊接不仅扩大了Ti_(3)CN层状结构的层间距,而且提升了其层结构稳定性,从而显著提高了储钠倍率性能和循环稳定性。在0.1Ag^(-1)电流密度下,Ti_(3)CN-PTCDA材料的比容量经过895次循环后可达127.9 mAh g^(-1),当电流密度提升至5.0Ag^(-1)时仍可保持51.8 mAh g^(-1)。本研究证明,二维储钠材料的层结构对其储钠倍率和循环稳定性有重要影响,该结论为设计高倍率二维储钠材料提供了新思路。
