Wang Jun, Liu Dongliang, Yuan Shun, Gao Bo, Cheng Lin, Zhang Yu, Chen Kaijia, Chen Aimin, Li Lianbi
School of Science, Xi'an Polytechnic University, 19 Jinhua South Road, Xi'an 710048, China.
Engineering Research Center of Flexible Radiation Protection Technology, Xi'an Polytechnic University, 19 Jinhua South Road, Xi'an 710048, China.
Molecules. 2023 Sep 27;28(19):6827. doi: 10.3390/molecules28196827.
Plasmonic-enhanced photocatalysis using visible light is considered a promising strategy for pollution photodegradation. However, there is still a lack of comprehensive and quantitative understanding of the underlying mechanisms and interactions involved. In this study, we employed a two-step process to fabricate arrays of ZnO nanosheets decorated with Au nanoparticles (Au-ZnO NS). Various characterization techniques were used to examine the morphological, structural, and chemical properties of the fabricated Au-ZnO NS array. Furthermore, we systematically investigated the photocatalytic degradation of methyl orange under visible light irradiation using Au-ZnO NS arrays prepared with varying numbers of photochemical reduction cycles. The results indicated that as the number of photochemical reduction cycles increased, the photodegradation efficiency initially increased but subsequently decreased. Under visible light irradiation, the Au-ZnO NS array obtained via four cycles of photochemical reduction exhibits the highest photocatalytic degradation rate of methyl orange 0.00926 min, which is six times higher than that of the ZnO NS array. To gain a better understanding of the plasmonic effect on photodegradation performance, we utilized electromagnetic simulations to quantitatively investigate the enhancement of electric fields in the Au-ZnO NS array. The simulations clearly presented the nonlinear dependencies of electric field intensity on the distribution of Au nanoparticles and the wavelength of radiation light, leading to a nonlinear enhancement of hot electron injection and eventual plasmonic photodegradation. The simulated model, corresponding to four cycles of photochemical reduction, exhibits the highest electric field intensity at 550 nm, which can be attributed to its strong plasmonic effect. This work provides mechanistic insights into plasmonic photocatalysts for utilizing visible light and represents a promising strategy for the rational design of high-performance visible light photocatalysts.
利用可见光的等离子体增强光催化被认为是一种有前途的污染光降解策略。然而，对于其中涉及的潜在机制和相互作用仍缺乏全面和定量的理解。在本研究中，我们采用两步法制备了装饰有金纳米颗粒（Au-ZnO NS）的ZnO纳米片阵列。使用各种表征技术来研究制备的Au-ZnO NS阵列的形态、结构和化学性质。此外，我们系统地研究了使用不同光化学还原循环次数制备的Au-ZnO NS阵列在可见光照射下对甲基橙的光催化降解。结果表明，随着光化学还原循环次数的增加，光降解效率最初增加，但随后降低。在可见光照射下，通过四个光化学还原循环获得的Au-ZnO NS阵列对甲基橙的光催化降解速率最高，为0.00926 min，比ZnO NS阵列高六倍。为了更好地理解等离子体效应对光降解性能的影响，我们利用电磁模拟定量研究了Au-ZnO NS阵列中电场的增强。模拟清楚地呈现了电场强度对金纳米颗粒分布和辐射光波长的非线性依赖性，导致热电子注入的非线性增强和最终的等离子体光降解。对应于四个光化学还原循环的模拟模型在550 nm处表现出最高的电场强度，这可归因于其强烈的等离子体效应。这项工作为利用可见光的等离子体光催化剂提供了机理见解，并代表了一种合理设计高性能可见光光催化剂的有前途的策略。
