ZnO/D-A共轭聚合物S型异质结高效光催化产H2O2及其电荷转移动力学研究
Efficient Photocatalytic Production of H2O2 over ZnO/D-A Conjugated Polymer S-Scheme Heterojunction and Charge Transfer Dynamics Investigation
吴优 1程畅 2戚克振 3程蓓 2张建军 4余家国 4张留洋4
作者信息
- 1. 大理大学药学院,云南 大理 671000;武汉理工大学,材料复合新技术国家重点实验室,武汉 430070
- 2. 武汉理工大学,材料复合新技术国家重点实验室,武汉 430070
- 3. 大理大学药学院,云南 大理 671000
- 4. 中国地质大学(武汉),材料与化学学院太阳燃料实验室,武汉 430078
- 折叠
摘要
光催化技术利用清洁、无污染的太阳能合成过氧化氢(H2O2).本研究通过Suzuki Miiyaura反应和水热法合成了ZnO/PBD S型异质结复合材料.优化后的ZnO/PBD复合材料的光催化产H2O2效率为4.07 mmol∙g-1∙h-1,是单一ZnO的5.4倍.光催化性能的显著提高归功于S型异质结的形成.紫外可见吸收光谱和原位光照X射线光电子能谱证实了S型异质结的形成.稳态荧光和飞秒瞬态吸收(fs-TA)光谱确定并验证了ZnO中缺陷态的存在.这些缺陷态会捕获光生电子,不利于光催化反应.S型异质结有效地促进了电子的分离和转移,从而缓解了这一问题.通过拟合fs-TA光谱得到了光生电子在这些缺陷态中的寿命,进一步证明了S型异质结中的载流子转移机制.该工作介绍了一种利用fs-TA光谱研究有机/无机S型异质结的新方法.
Abstract
Photocatalytic technology harnesses clean,non-polluting solar energy to synthesize hydrogen peroxide(H2O2).In this study,ZnO/PBD S-scheme heterojunction composites,featuring ZnO nanoparticles on a donor-acceptor conjugated polymer substrate(PBD),were synthesized via the Suzuki-Miyaura reaction and hydrothermal method.The optimal ZnO/PBD composite achieved an H2O2 production efficiency of 4.07 mmol·g-1·h-1,which is 5.4 times higher than that of pristine ZnO.This significant enhancement is attributed to the formation of S-scheme heterojunctions.The successful construction of S-scheme heterojunctions was confirmed through UV-visible absorption spectroscopy and in situ irradiated X-ray photoelectron spectroscopy.Steady-state photoluminescence and femtosecond transient absorption(fs-TA)spectroscopies identified and verified the presence of defect states in ZnO.These defect states trap photogenerated electrons,adversely affecting the photocatalytic reaction.However,the S-scheme heterojunction effectively promotes the separation and transfer of electrons,mitigating this issue.The measured lifetimes of photogenerated electrons in these defect states,as determined by fitted fs-TA decay kinetics,provided further evidence of the carrier transfer mechanism in S-scheme heterojunctions.This work introduces a novel approach for studying organic/inorganic S-scheme heterojunctions using fs-TA spectroscopy.
关键词
光催化产H2O2/S型异质结/ZnO缺陷态/fs-TA光谱Key words
Photocatalytic production of H2O2/S-scheme heterojunction/ZnO defect states/fs-TA spectroscopy引用本文复制引用
出版年
2024
国家科技期刊平台
NSTL
万方数据