同质异形g-C3N4多级孔海绵的构筑及其光化学治藻初探

The prevention and cure of the cyanobacterial blooms have become not only an interdisciplinary research hotspot worldwide, but the urgent need for the coordinated and sustainable developments of current society, economy, and environment in our country. As one of the most prospective measures, the photochemical strategy for algal treatment has been lack of a tailored material medium and corresponding implementation method. For addressing these key constraints integrally, in this project, we aim to adopt an assembly method by using the micro/nano-scale units with different degrees of polymerization, and prepare a novel paramorph-structured g-C3N4 sponge with hierarchical porous structure. Respectively, the scattering effect between the inside pores and the junction effect between the semiconductors have been well employed to enhance the matrix performances of light absorption and exciton excitation. Such a photochemical system is designed to float on the surface of the water, achieving multiple functions including continuous algae electrostatic adsorption and concentration, efficient photochemical algal killing and toxin molecules degradation. Moreover, the photosynthesized oxygen from the cyanobacteria can be used to ease the photochemical process of hypoxia. Based on the exploration and optimization of the assembly process, systematic studies on the material and energy transport mechanism will be carried out, with a further evaluation of the potential application in cyanobacteria killing and cyanotoxins degradation, which will provide references for the studies on 3D hierarchical porous material construction, functional coupling mechanism and photochemical control of algae.

蓝藻水华的防治是全世界交叉学科的研究热点，更是当下我国社会、经济与环境互相协调及可持续发展的迫切需要。作为极具前景的手段之一，光化学治藻策略一直以来缺乏量身设计的材料媒介和实施方法。综合针对其中的关键制约因素，本项目拟采用异聚度微纳单元组装手段，构筑一种具有同质异形结构的g-C3N4多级孔海绵材料，分别利用其孔道散射效应和半导体结效应提高基质的光能吸收和激子激发性能。设想其作为水面浮体式的光化学系统，实现连续式的藻类静电吸附浓集、高效光化学灭杀及藻毒素分子降解等多重功能于一体，并能有效利用藻类光合供氧缓解光化学过程的缺氧制约。探索并优化微纳单元组装工艺，系统研究该新型光化学体系中物质与能量传输机制，评价其在藻类灭杀和藻毒素降解方面的应用潜力，为三维多级孔材料的构筑、功能耦合机制探究及光化学藻类防治提供鉴。

以半导体材料为媒介的光化学技术有望成为一种极富应用前景的安全治藻策略，本项目针对目前光化学治藻应用中的瓶颈问题，设计并可控制备出表面官能团、形状和孔道结构可调的同质异形结构g-C3N4海绵材料 (3D g-C3N4)。3D g-C3N4具有显著增强的光能吸收和激子激发性能，可漂浮于实施水体水面，实现连续式的藻类吸附浓集、高效的光能利用和自供氧灭杀于一体的光化学治藻。在此基础上，为加强在蓝藻复苏阶段的防治治理，本项目提出激光热聚合的制备技术，将光热材料均匀负载在3D g-C3N4表面，利用光热效应较低温水体中实现吸附富集，随后进行光化学灭杀。相比于未改性的3D g-C3N4，与光热材料耦合的3D g-C3N4光化学治藻的效率可提高2倍，为蓝藻复苏阶段的光化学防治治理提供新的催化体系。