分子模拟在废水光催化脱氮实验教学的应用

Application of molecular simulation in photocatalytic denitrification experiment teaching from wastewater

设计光催化脱氮实验,利用水热横向热剥离法制备Cl/S共掺杂的无金属氮化碳纳米管作为光催化剂(Cl/S-TCN),对催化剂进行表征分析。使用Materialstudio模拟软件,探究了催化材料的电子结构变化和光催化脱氮反应。与三聚氰胺直接煅烧获得氮化碳对比发现,Cl/S-TCN具有更大的比表面积和更强的光响应强度,提高了光催化脱氮性能。DFT计算表明,表面Cl和S掺杂剂优先吸附NO3-中的O原子,并通过O原子将光诱导e-传递给N原子,最终破坏N-O键。该实验旨在培养学生从分子角度分析无金属催化剂在可见光下驱动脱氮反应,加深学生对化学知识的理解,提高学生解决复杂工程问题的能力。

In this paper,the photocatalytic denitrification reaction(PCDN)experiment was designed,and a hydrothermal transverse thermal stripping method was developed to prepare Cl/S doped metal free carbon nitride nanotubes as photocatalyst(Cl/S-TCN).The changes of electronic structure and PCDN reaction in the photocatalytic process were simulated by Material Studio software.Compared with carbon nitride obtained by direct calcination of melamine,Cl/S-TCN has larger specific surface area and stronger light response intensity which improves the performance of PCDN reaction.DFT calculation shows that the surface Cl and S dopants preferentially adsorbs the O atom in NO-3,c denitrification reaction PCDN driven by metatransfers e-to the N atom through the O atom,and finally destroys the N-O bond.The experiment aims to train students to analyze the photocatalytic free catalyst under visible light from the molecular point of view,deepen studentsunderstanding of chemistry knowledge and improve students’ability to solve complex engineering problems.