基于Z型光阳极的光催化燃料电池设计与除污产电性能研究

Photocatalytic fuel cell (PFC) has attracted much attention in the field of wastewater treatment because of the fact that energy recovery and pollution control can be realized simultaneously. However, it is still difficult to apply this technology into practice due to the low efficiency of pollutants removal and electricity generation. Z-scheme photocatalysts usually possess relatively high separation efficiency of photogenerated carriers and are able to be induced by visible-light. Furthermore, Z-scheme photocatalysts commonly have more positive valence band and more negative conduction band at the same time. Therefore, in this program, Z-scheme photocatalytic anodes will be designed and used in PFC. Carbon nitride will be selected as photosystem I and silver phosphate will be used as photosystem II. Some methods of doping and modifying will be investigated to adjust the band structure of Z-scheme photocatalysts. The methods and influencing factors of constructing Z-scheme photoanode will be also discussed in order to explore the mechanism involved. The performance of PFC will be further improved by the bandgap engineering design. Additionally, the contribution of cathodes (reduction of oxygen into water or hydrogen peroxide) to the performance of PFC will be investigated. This program involving the design of PFC wtih Z-scheme photocatalysts as anodes will be beneficial to promoting the performance of PFC in terms of decontamination and electricity generation. It is expected to provide a new idea for wastewater treatment and reclamation.

在废水处理领域，光催化燃料电池技术因兼顾污染治理和能源回收而备受关注。但该技术仍受制于污染物去除效率不高，电能输出不强而难以实用。Z型光催化剂光生载流子分离效率高、易于设计成可见光响应型，且具有价带电势更正、导带电势更负的特性。因此，本项目拟将Z型光催化剂用于光催化燃料电池光阳极设计。以氮化碳为光反应系统I，以磷酸银为光反应系统II构建Z型光催化剂，并通过掺杂、改性对复合材料进行能带结构调整。重点研究Z型光催化阳极的构建方法和影响因素，揭示其在光催化燃料电池除污、产电中的作用和机理。通过能带工程，进一步优化光催化燃料电池性能。此外，还会考察阴极作用方式（还原氧生成水或过氧化氢）对光催化燃料电池性能的影响。本研究将Z型光催化体系用于光催化燃料电池光阳极的设计中，期望同时获得更好的污水处理效果和更高的产电性能，为废水处理与资源化提供新思路。

本项目研究从Z型光阳极构建出发，研究了光阳极材料种类、能带结构调节对光催化燃料电池性能的影响，同时考察了阴极作用方式在光催化燃料电池除污产电中的作用。主要结果及结论如下：.（1）以Z型光催化剂Ag3PO4@g-C3N4为光阳极组建Z体系光催化燃料电池（Z-PFC）。结果表明，相比于磷酸银或氮化碳单独组分光阳极PFC，Z-PFC除污能力分别提高3.65倍和2.53倍，产电能力分别提升1.46倍和90.4倍。研究还发现半导体内阻、污染物初始浓度、pH值、污染物种类和曝气等因素对PFC的性能都具有一定影响。.（2）对g-C3N4和Ag3PO4分别进行磷掺杂和铋掺杂改性，二者能带结构向相反方向调整，这促使二者更易组建Z型异质结光催化剂，且光催化性能显著提升。将其用作光阳极组建PFC，结果显示，除污能力较未掺杂改性PFC明显增强。Z-PFC的最大输出功率密度（Pmax）达到8.22 µW/cm2，相比于未改性Ag3PO4@g-C3N4 PFC而言，提高35.6%。由此可见，双掺杂改性进一步提升了Z型PFC的除污产电性能。.（3）PFC阴极作用方式对其除污产电性能有重要影响。金纳米粒子负载氮掺杂石墨烯（NGO/Au）阴极提高了外电路电子的利用效率，促进了双氧水的生成。与传统铂黑阴极和光阴极氧化亚铜相比，过氧化氢产率分别提高2.20倍和3.52倍，显著增强了PFC的除污能力。同时，NGO/Au阴极PFC最大功率密度Pmax达到40.01 µW/cm2，分别是氧化亚铜PFC和铂黑PFC的3.05倍和2.60倍。.（4）本项目还尝试了其他Z型光催化剂，如OPCN/NCDs/Bi2O4、双Z型异质结光催化剂Ag3PO4/AgBr/g-C3N4，在PFC中的应用。结果证实，Z型光催化剂阳极PFC除污产电能力均好于单一组分PFC。.本项目研究为PFC技术的发展提供了技术支持，也为有机废水的资源化处理提供了新思路。