Phase transformation and microwave hydrothermal guided a novel double Z-scheme ternary vanadate heterojunction with highly efficient photocatalytic performance
Phase transformation and microwave hydrothermal guided a novel double Z-scheme ternary vanadate heterojunction with highly efficient photocatalytic performance
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DOI：
10.1016/j.apcatb.2018.06.010
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发表时间：
2018-12
期刊：
影响因子：
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通讯作者：
Debin Zeng;Kai Yang;Changling Yu;Changling Yu;Fanyun Chen;Xiaoxiao Li;Zhanghua Wu;Hong Liu
中科院分区：
文献类型：
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作者：
Debin Zeng;Kai Yang;Changling Yu;Changling Yu;Fanyun Chen;Xiaoxiao Li;Zhanghua Wu;Hong Liu
半导体基异构体具有高载流子导向性、高活性和稳定性，在可见光驱动的多组份光催化体系中，由于其在环境保护和能源转换方面的长期需求，受到了极大的关注。然而，三元组分纳米晶体的构建通常要经历多个复杂的步骤，限制了其应用。在本工作中，我们在低成本的微波水热助剂中，成功地设计并合成了一种新型的双Z-Z型结构的锌钒酸锌/锌钒酸锌/氧化锌三元异质结构体系(THS)，该体系在低成本的微波水热助剂中，通过加热的自相变，表现出良好的光催化性能。在这种情况下，采用Zn3(OH)2V2O7·2H2O作为异质结构前驱体是制备THS材料的关键，它不仅增强了与其结构的相互作用，而且保持了介孔纳米片状结构。实验证明，锌是先失去水，然后部分锌(VO)2发生自相变，生成锌钒酸锌和氧化锌(Zn3(OH)2V2O7·2H2O → Zn3(VO4)2→ Zn2V2O7+ ZnO)，，从而得到双Z晶型结构。因此，将界面主导的光催化活性(如去除苯酚和染料)作为理想的实验来验证所构建的双Z方案THS材料的响应性，该材料具有窄的带隙、紧密的接触界面、宽的可见光吸收和更有效的电荷转移和分离，从而实现了高的可见光催化活性和稳定的循环。荧光光谱、自由基捕获实验和电子自旋共振实验证实，双Z机制引起的光生h+和e−的非传统输运对目标污染物的有效去除起着重要作用。这种合成方法可能会产生双Z方案的THS，从而推动异质过渡金属钒酸盐的大规模应用发展。
Semiconductor-based heteronanostructures with the high carriers-flow steering and high activity and stability in the visible-light-driven multicomponent photocatalytic system have been of great concern due to its long-standing demand in the wide application of environmental protection and energy conversion. However, the construction of ternary-component nanocrystals usally undergos multiple complex steps to restrict its application. In the work, we successfully report the facile design and synthesis of a novel double Z-scheme Zn3(VO4)2/Zn2V2O7/ZnO ternary heteronanostructure system (THS)viaself-phase transition with heating on basis of the Zn3(OH)2V2O7·2H2O precursor in a low-cost microwave hydrothermal assistant, which exhibited excellent photocatalytic performances. In this case, the employment of Zn3(OH)2V2O7·2H2O as the heteronanostructure precursor is the key for fabricating the THS material, which not only boosted the interaction with its structure and but also maintained the mesoporous nanosheet structure. It has been proved that Zn3(OH)2V2O7·2H2O firstly lost it H2O and then the partial Zn3(VO4)2underwent the self-phase transition process to produce Zn2V2O7and ZnO (Zn3(OH)2V2O7·2H2O → Zn3(VO4)2→ Zn2V2O7+ ZnO), which obtained the double Z-scheme THS. Accordingly, the interfacial-dominated photocatalysis reactivities such as the removal of phenols and dyes were used as ideal experiments to verify the responsibility of the constructed double Z-scheme THS material that was equipped with the narrow band gap, intimate contact interface, the wide visible light absortion and more efficient charge transfer and separation for high visible-light photocatalytic reactivity and stable cycling. PL spectra, radicals trapping experiments and ESR tests confirmed that the nontraditional transport of photoinduced h+and e−caused by double Z-scheme mechanism played an important role in the efficient removing the target pollutants. Such a synthetic approach maybe render double Z-scheme THS to advance the development for large-scale applications of the hetero-transition metal vanadates.