摘要
为强化学生对新污染物处理理论和实验技能的掌握,设计了光自芬顿/过氧单硫酸盐(PMS)协同体系在自然光条件下对新污染物的强化降解实验。利用水热法和浸渍法制备改性氮化碳空心球MoS_(2)/TCN_(Cl-S)(P),以四环素(TC)作为新污染物代表,构建了光自芬顿/PMS协同体系,基于其耦合效应,提高在自然光条件下污染物的降解效率。结果表明,光自芬顿/PMS体系对TC在120min内的降解率可以达到80%,较不引入PMS的光自芬顿体系提高了30%。其原因在于光自芬顿反应中产生的H_(2)O_(2)与PMS发生协同作用,产生了更多的·O_(2)^(-)、SO_(4)^(-)·和^(1)O_(2)等活性自由基,从而提高了TC的降解效率。该实验设计体系有助于促进学生对高级氧化技术的掌握,为学生科研创新能力培养体系的构建提供参考。
[Objective]g-C_(3)N_(4) is a photocatalytic material that can be prepared easily at low cost and exhibits good stability.However,it has limitations,such as a small specific surface area and low efficiency in photogenerated carrier separation.The photocatalytic performance of g-C_(3)N_(4) can be enhanced by modifying the microstructure of carbon nitride through morphology regulation,element doping,and heterostructure construction.At present,most studies on photocatalysis focus on simulating visible light for degradation experiments to investigate the catalyst’s performance and influencing factors.However,limited studies have been conducted under natural light conditions that hamper the practicality of research findings.[Methods]Herein,Cl/S codoped carbon nitride was synthesized using a hydrothermal stripping method and combined with MoS_(2) to form MoS_(2)/TCN_(Cl-S) composite material.Furthermore,it was loaded onto Al_(2)O_(3) hollow spheres to prepare modified carbon nitride hollow sphere MoS_(2)/TCN_(Cl-S)(P),enabling recycling of the composite material.Crystal phase composition and morphology of the catalyst were analyzed using SEM,TEM,UV–Vis spectroscopy,and XRD techniques.Moreover,the mechanism behind photogenerated carrier generation,recombination,and transport was investigated through I–T measurements as well as PL and EIS characterization methods.Furthermore,a photo-self-Fenton/PMS collaborative system was constructed under visible light conditions to evaluate TC degradation efficiency considering different TC concentrations,catalyst dosage,pH,and PMS concentration.This enabled the evaluation of the catalyst’s performance and its influencing factors under natural light conditions.Radical quenching experiments and ESR operations contributed to the PMS collaborative system to analyze the reasons for the difference in free radical contribution and to summarize the mechanism of TC degradation in the process.[Results]The results demonstrate that the photo-self-Fenton/PMS system achieved an 80%degradation rate of TC within 120 min,indicating the high feasibility of photocatalysis under natural light.The photo-self-Fenton/PMS collaborative system autonomously generated H_(2)O_(2) upon PMS addition and enhanced the photocatalytic efficiency by approximately 30%,thereby addressing the limitations of traditional photo-Fenton technology requiring additional Fe2+and H_(2)O_(2).Furthermore,the incorporation of PMS enhanced the anti-interference capability of the photocatalytic system,thereby minimizing the effect of pollutant concentration,pH,and other factors on its performance.TCN_(Cl-S),a double-doped carbon nitride nanotube cluster of Cl/S with a diameter of approximately 69 nm,was synthesized via the hydrothermal stripping method.Subsequently,the MoS_(2)/TCN_(Cl-S) composite was formed,combining MoS_(2) with TCN_(Cl-S)(P).To achieve an efficient degradation of TC under visible light,a photo-self-Fenton/PMS collaborative reaction system was constructed.[Conclusions]This study achieved efficient degradation of TC under visible light through a highly efficient carbon nitride composite catalyst.By investigating free radical production and transformation mechanisms,it is observed that PMS introduction promotes increased •O_(2)^(-) generation in synergy with new radicals such as ^(1)O_(2) and SO_(4)^(-)•,ultimately strengthening TC degradation.This experiment design involves a comprehensive application of basic knowledge and theoretical practice,such as the principle of environmental catalysis and degradation of water-based environmental pollutants,which helps strengthen students’understanding of the textbook content and improve their practical operation ability.
作者
刘芳
刘嘉梁
安蓓雅
刘柃妤
李石
王永强
LIU Fang;LIU Jiaiang;AN Beiya;LIU Lingyu;LI Shi;WANG Yongqiang(College of Chemistry and Chemical Engineering,China University of Petroleum(East China),Qingdao 266580,China)
出处
《实验技术与管理》
CAS
北大核心
2024年第1期26-36,共11页
Experimental Technology and Management
基金
山东省教改项目(M2021132)
中国石油大学(华东)教改项目(CM2022023)。
关键词
自然光
新污染物
改性氮化碳空心球
光自芬顿/PMS协同系统
natural light
emerging pollutants
modified carbon nitride hollow spheres
photo-self-Fenton/peroxymonosulfate(PMS)synergistic system
