Blue-edge slow photons promoting visible-light hydrogen production on gradient ternary 3DOM TiO2-Au-CdS photonic crystals. (May 2018)

• Record Type: Journal Article
• Authors: Zhao, Heng; Hu, Zhiyi; Liu, Jing; Li, Yu; Wu, Min; Van Tendeloo, Gustaaf; Su, Bao-Lian
• Is Part Of: Nano energy. Volume 47(2018)
• Page Start: 266
• Page End: 274
• Publication Date: 2018-05
• Subjects: Gradient ternary 3DOM TiO2-Au-CdS -- Photonic crystals -- Blue-edge -- Red-edge -- Slow photon effect -- Photocatalytic H2 production; Nanoscience -- Periodicals; Nanotechnology -- Periodicals; Nanostructured materials -- Periodicals; Power resources -- Technological innovations -- Periodicals; Nanoscience; Nanostructured materials; Nanotechnology; Power resources -- Technological innovations; Periodicals; 621.042
• DOI: 10.1016/j.nanoen.2018.02.052
• Languages: English
• ISSNs: 2211-2855

Abstract

Abstract: The slow photon effect, a structural effect of photonic crystal photocatalyst, is very efficient in the enhancement of photocatalytic reactions. However, slow photons in powdered photonic crystal photocatalyst have rarely been discussed because they are usually randomly oriented when the photocatalytic reaction happens in solution under constant stirring. In this work, for the first time we design a gradient ternary TiO2 -Au-CdS photonic crystal based on three-dimensionally ordered macroporous (3DOM) TiO2 as skeleton, Au as electron transfer medium and CdS as active material for photocatalytic H2 production under visible-light. As a result, this gradient ternary photocatalyst is favorable to simultaneously enhance light absorption, extend the light responsive region and reduce the recombination rate of the charge carriers. In particular, we found that slow photons at blue-edge exhibit much higher photocatalytic activity than that at red-edge. The photonic crystal photocatalyst with a macropore size of 250 nm exhibits the highest visible-light H2 production rate of 3.50 mmolh −1 g −1 due to the slow photon energy at the blue-edge to significantly enhance the incident photons utilization. This work verifies that slow photons at the blue-edge can largely enhance light harvesting and sheds a light on designing the powdered photonic crystal photocatalyst to promote the photocatalytic H2 production via slow photon effect. Graphical abstract: The blue-edge slow photon effect in gradient ternary TiO2 -Au-CdS powdered photonic crystal photocatalysts with 3DOM structure ensures excellent visible-light H2 production. fx1 Highlights: Designing gradient ternary TiO2 -Au-CdS powdered photonic crystal photocatalysts. Verifying the photocatalytic enhancement by slow photon effect. Realizing enhanced H2 production rate under visible-light for TiO2 -Au-CdS. Slow photon effect at the blue-edge being higher than that at red-edge.