Enhanced photocatalytic performance from NiS/TiO2 p-n heterojunction nanosheet arrays. (May 2018)

• Record Type: Journal Article
• Authors: Qian, Long-Long; Li, Yan; Li, Jian-feng; Wang, Cheng-Wei
• Is Part Of: Superlattices and microstructures. Volume 117(2018)
• Page Start: 317
• Page End: 329
• Publication Date: 2018-05
• Subjects: TiO2 nanosheet arrays -- NiS nanoparticles -- p-n heterojunction -- Photocatalysis; Superlattices as materials -- Periodicals; Microstructure -- Periodicals; Semiconductors -- Periodicals; Superréseaux -- Périodiques; Microstructure (Physique) -- Périodiques; Semiconducteurs -- Périodiques; 621.38152
• DOI: 10.1016/j.spmi.2018.03.060
• Languages: English
• ISSNs: 0749-6036

Abstract

Abstract: A novel p-n heterostructural film photocatalyst of oriented NiS/TiO2 nanosheet arrays were designed and successfully fabricated via a simple two-step hydrothermal process, and its photodegradation activities of methyl orange (MO) were detailedly investigated. Combining p-type NiS nanoparticles with n-type TiO2 nanosheets to construct distributed p-n heterojunctions, the absorption edge of NiS/TiO2 red-shifted to about 471 nm and its photoresponse in visible range significantly enhanced. Compared with pure TiO2 nanosheet arrays (NSAs), the assembled NiS/TiO2 p-n heterostructural arrays with 0.003 M NiS in hydrothermal precursor solution showed an optimal degradation rate of k = 0.7368 h −1 for MO, achieving 76.3% photocatalytic efficiency within 120 min, which is about 2.34 times higher than that of pure TiO2 nanosheet arrays (k = 0.3144 h −1 ). Such enhanced photocatalytic activities should be attributed to both the high efficiency of photogenerated charge separation by the built-in electric field at interfaces of NiS-TiO2 and the oriented thin nanosheet structures for smoothly charge transportation for redox reactions at surfaces of NiS/TiO2 . Highlights: The highlights of this work include the following three aspects: Oriented p-n heterostructures of NiS/TiO2 nanosheet arrays are designed and fabricated. NiS/TiO2 p-n heterostructures can lead to higher separation and transfer efficiency of carries. NiS/TiO2 nanosheet arrays possess better and stable photodegradation performance.