Au纳米粒子表面等离子共振效应(SPR)增强Au/Bi2WO6异质纳米结构的光催化活性

采用水热-光还原法在三维Bi₂WO₆的二级结构纳米片表面原位沉积Au纳米粒子(Au NPs), 成功获得了具有可见光响应活性的Au/Bi₂WO₆异质光催化剂, 并借助XRD、FE-SEM、HR-TEM、XPS和 UV-Vis-DRS谱等手段对其物相组成、形貌和光吸收特性进行表征, 以罗丹明B(RhB)和苯酚为模型污染物对其光催化性能进行研究。实验结果表明, 与纯Bi₂WO₆相比, 所得Au/Bi₂WO₆异质纳米结构对染料降解具有较高的活性, 当Au负载量为1.5at%时, Au/Bi₂WO₆复合催化剂的催化活性最好, 其光催化降解RhB和苯酚的表观速率常数分别是纯Bi₂WO₆的1.5倍和2.2倍。自由基捕获实验表明, 光生空穴(h⁺)和?O₂^-是RhB在Au/Bi₂WO₆催化材料上光催化降解的主要活性物种。机理分析表明, Au/Bi₂WO₆活性增强归因于光生电子从Bi₂WO₆的导带向AuNPs表面迁移, 降低光生电子-空穴对的复合率, 同时, Au NPs 的等离子共振效应(SPR)拓展了催化剂在可见光区的响应范围, 从而显著提高了Au/Bi₂WO₆异质光催化的剂活性。Au NPs修饰Bi₂WO₆异质催化剂光太阳能驱动在污水处理方面具有潜在应用。

Au Nanoparticles (NPs) Surface Plasmon Resonance Enhanced Photocatalytic Activities of Au/Bi2WO6 Heterogeneous Nanostructures

Novel visible-light-responsive Au/Bi₂WO₆ heterogeneous nanostructures were successfully prepared through in situ growth gold nanoparticles (Au NPs) on the second-structural nanosheets of three-dimensional (3D) Bi₂WO₆ via a facile photoreduction process. XRD, FE-SEM, HR-TEM, FT-IR, XPS, and UV-Vis-DRS spectra were employed to investigate the phase composition, morgphology and light-absorption properties of as-preapared samples. Rhodamine B(RhB) and phenol were selected as model pollutants to evaluate photocatalytic activities of samples. The experimental results reveal that the as-prepared Au/Bi₂WO₆ heterogeneous nanostructures exhibit much higher photocatalytic activities than pure Bi₂WO₆ for dye degradation. It is also revealed that 1.5at%Au/Bi₂WO₆ sample exhibit the best photocatalytic activities in the degradation process of RhB and phenol, the apparent rate constant is about 1.5 and 2.2 times as high as that of pure Bi₂WO₆ under visible light irradiation, respectively. Moreover, the trapping experiments results show that photogenerated hole (h⁺) and ·O₂^- serve as the main active species for the photodegradation of RhB over Au/Bi₂WO₆ heterogeneous nanostructures. The enhanced photocatalytic efficiencies of Au/Bi₂WO₆ heterogeneous nanostructures are attributed to the charge transfer from Bi₂WO₆ to the deposited Au NPs as well as their surface plasmon resonance (SPR) absorption, which enhance the migration efficiency of the electron-holes and retard the recombination of electrons-hole pairs. Au NPs decorated Bi₂WO₆ heterogeneous nanostructures have considerable potential applications in solar-driven wastewater treatment.