Promoting charge separation in dual defect mediated Z-scheme MoS2/g-C3N4 photocatalysts for enhanced photocatalytic degradation activity: synergistic effect insight
Promoting charge separation in dual defect mediated Z-scheme MoS2/g-C3N4 photocatalysts for enhanced photocatalytic degradation activity: synergistic effect insight
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DOI：
10.1016/j.colsurfa.2020.124668
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发表时间：
2020-06
期刊：
影响因子：
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通讯作者：
Haiping Liu;Jing Liang;Li Shao;Du Jinge-;Qiancheng Gao;Shuai Fu;Li Li-Li;Miao Hu;Fengying Zhao-
中科院分区：
文献类型：
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作者：
Haiping Liu;Jing Liang;Li Shao;Du Jinge-;Qiancheng Gao;Shuai Fu;Li Li-Li;Miao Hu;Fengying Zhao-
通过简单的超声分散和退火法制备了双缺陷介导型MoS2/g-C3N4光催化剂。对其结构、光学和电学性质进行了系统的表征。X射线光电子能谱(XPS)分析表明，MoS2通过较强的界面静电作用锚定在g-C3N4上，从而在接触界面形成内建电场。优化后的MoS_2/g-C_3N_4异质结对双酚A(BPA)具有较高的光解效率，反应速率归一化到比表面积为3.22 × 10−4G·−_1M−_2，分别是g-C_3N_4和MoS_2的10.0和6.7倍。MoS_2/g-C_3N_4光催化活性提高的原因是在MoS_2和g-C_3N_4之间形成了紧密的Z型表面异质结构，从而提高了光捕获能力，促进了电荷的快速分离，创造了更多的活性中心。考察了阴离子对降解效率的影响。用三维激发发射矩阵(3DEEM)荧光技术研究了双酚A的降解活性和降解程度。通过电子自旋共振、自由基清除剂实验和光谱定量技术证明了Z-方案电荷转移机理以及空穴(h+)和超氧阴离子自由基(dotO2-−)对电荷转移的重要贡献。本工作为高效异质结构光催化剂的设计提供了一种新的方案。
The dual defect mediated Z-scheme MoS2/g-C3N4photocatalyst was fabricated via a simple ultrasonic dispersion and annealing method. The structural, optical and electronic property was systematically characterized. X-ray photoelectron spectroscopy (XPS) analysis demonstrated that the MoS2was anchored on the g-C3N4through strong interface electrostatic interaction, which led to the formation of built-in electric field at the contact interface. The optimized MoS2/g-C3N4heterojunction achieved a superior photoefficiency towards bisphenol A (BPA) degradation and exhibited the reaction rate normalized to specific surface area of 3.22 × 10−4g·min−1m−2, approximately 10.0 and 6.7 times larger than these of g-C3N4and MoS2, respectively. The origin of the enhanced photocatalytic activity of MoS2/g-C3N4was attributed to the formation of intimate Z-scheme surface heterostructure between MoS2and g-C3N4, thus improved the light-harvesting ability, facilitated fast charge separation and created more active sites. The impact of anionic towards degradation efficiency was investigated. The degradation activity and degree of BPA were investigated by three-dimensional excitation-emission matrix (3D EEM) fluorescence technique. The Z-scheme charge transfer mechanism and the significant contribution of holes (h+) and superoxide radicals (radical dotO2−) were demonstrated by electron spinning resonance (EPR), radical scavenger experiment and spectral quantification technology. This work could offer a new protocol for the design of highly efficient heterostructure photocatalysts towards environmental remediation.