Controlled growth of ultrasmall Cu2O clusters on TiO2 nanoparticles by atmospheric-pressure atomic layer deposition for enhanced photocatalytic activity. (26th July 2021)

• Record Type: Journal Article
• Authors: Benz, Dominik; Nguyen, Y-Nhi T; Le, Thanh-Lieu T; Le, Thanh-Hiep T; Le, Viet-Thong; van Ommen, J Ruud; Bui, Hao Van
• Is Part Of: Nanotechnology. Volume 32:Number 42(2021)
• Publication Date: 2021-07-26
• Subjects: atmospheric pressure atomic layer deposition -- Cu2O/TiO2 photocatalysts -- fluidized bed reactor -- surface modification -- cuprous oxide -- organic dyes photodegradation; Nanotechnology -- Periodicals; Nanotechnology -- Periodicals; Nanotechnology; Publications périodiques; Nanotechnologies; Periodicals; 620.5
• DOI: 10.1088/1361-6528/ac10e2
• Languages: English
• ISSNs: 0957-4484

Abstract

Abstract: This work presents a gas-phase approach for the synthesis of Cu2 O/TiO2 powder-based photocatalysts using atomic layer deposition (ALD). The process is carried out in a fluidized bed reactor working at atmospheric pressure using (trimethylvinylsilyl)-hexafluoroacetulacetonate copper(I) as the Cu-precursor and H2 O vapor as the oxidizer. The saturating regime of the chemical reactions and the linear growth of ALD are achieved. In combination with the unsaturated regime, the ALD approach enables the deposition of ultrasmall Cu2 O clusters with average diameters in the range of 1.3–2.0 nm, narrow particle size distributions and tunable Cu2 O loadings on P25 TiO2 nanoparticles. The photocatalytic performance of Cu2 O/TiO2 photocatalysts is investigated by the degradation of organic dyes, including Rhodamine B (RhB), methyl orange, and methylene blue; the results demonstrate that the surface modification of TiO2 nanoparticles by Cu2 O nanoclusters significantly enhances the photocatalytic activity of TiO2 . This is attributed to the efficient charge transfer between Cu2 O and TiO2 that reduces the charge recombination. The photocatalytic reaction mechanism is further investigated for the degradation of RhB, revealing the dominating role of holes, which contribute to both direct hole oxidation and indirect oxidation (i.e. via the formation of hydroxyl radicals). Our approach provides a fast, scalable and efficient process to deposit ultrasmall Cu2 O clusters in a controllable fashion for surface engineering and modification.