Prussian blue as a co-catalyst for enhanced Cr(vi) photocatalytic reduction promoted by titania-based nanoparticles and aerogels

Author(s)

Ferreira-Neto, Elias Paiva ^{[1, 2]} ; Ullah, Sajjad ^{[2, 3, 4]} ; Perissinotto, Amanda Pasquoto ^[1] ; de Vicente, Fabio S. ^[5] ; Lima Ribeiro, Sidney Jose ^[2] ; Worsley, Marcus Andre ^[6] ; Rodrigues-Filho, Ubirajara Pereira ^[1]

Affiliation

^[1] Univ Sao Paulo, Inst Chem Sao Carlos, BR-13560970 Sao Carlos, SP - Brazil

^[2] Sao Paulo State Univ UNESP, Inst Chem, BR-14800060 Araraquara, SP - Brazil

^[3] Univ Peshawar, Inst Chem Sci, POB 25120, Peshawar - Pakistan

^[4] Univ Fed Mato Grosso do Sul, Inst Phys, BR-79070900 Campo Grande, MS - Brazil

^[5] Sao Paulo State Univ UNESP, Inst Geosci & Exact Sci, Dept Phys, BR-13506970 Rio Claro, SP - Brazil

^[6] Lawrence Livermore Natl Lab, Phys & Life Sci Directorate, Livermore, CA 94550 - USA

• Document type: Journal article
• Source: NEW JOURNAL OF CHEMISTRY; v. 45, n. 23, p. 10217-10231, JUN 21 2021.
• Web of Science Citations: 0

Abstract

Hexavalent chromium (Cr(vi)) is an noxious and highly toxic heavy metal that presents a serious threat to human health if present even in low concentrations in drinking water. Photocatalytic reduction of Cr(vi) to its less toxic Cr(iii) state is a potential strategy to combat Cr(vi) pollution, but the efficiency of the process is low, especially in the absence of hole scavenger organic reagents. To address this issue and prepare efficient photocatalysts for Cr(vi) removal from water, in this study, we explored Prussian blue (PB) as a co-catalyst for improving the photoreduction performance of different high surface area TiO2-based materials (titania or silica-titania nanoparticles and aerogels). The photocatalyst nanomaterials were surface-modified with nanocrystalline PB using the photodeposition route. The PB layer acts as an effective electron acceptor/mediator between the semiconductor photocatalyst and Cr(vi) species. All the PB-modified photocatalysts exhibit higher photocatalytic activity (up to 9 times faster) as compared to the unmodified photocatalysts towards reduction of Cr(vi). Importantly, the PB-modified photocatalysts exhibited high photocatalytic performance (98-99% reduction in 40 min for pH = 5.6 and in 10 min for pH = 3) without addition of organic reagents. The simple approach reported herein can be followed to prepare new PB-photocatalyst systems with improved photocatalytic performance towards Cr(vi) reduction and other target applications. (AU)

• FAPESP's process: 16/10939-0 - TiO2 based nanostructured materials modified with Prussian Blue and Transition Metal Disulfides as photocatalysts for CO2 reduction
• Grantee: Elias Paiva Ferreira Neto
• Support Opportunities: Scholarships abroad - Research Internship - Doctorate
• FAPESP's process: 13/24948-3 - CO2 Fixation by SiO2@TiO2 nanoparticles decorated with Iron Ferrocyanide (Prussian Blue) and Ruthenium Ferrocyanide: Toward high Sustainability of Biorefineries and Ammonia Synthesis Plants.
• Grantee: Elias Paiva Ferreira Neto
• Support Opportunities: Scholarships in Brazil - Doctorate
• FAPESP's process: 18/19785-1 - CO2 as a raw material for hybrid multi-functional materials: improving the sustainability of industrial processes
• Grantee: Ubirajara Pereira Rodrigues Filho
• Support Opportunities: Research Program on Global Climate Change - Regular Grants
• FAPESP's process: 18/01934-0 - Aerogels based on transition metal disulfides and bacterial cellulose: bifunctional nanomaterials with photocatalytic and adsorptive properties for environmental applications
• Grantee: Elias Paiva Ferreira Neto
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• FAPESP's process: 15/22828-6 - Pushing the boundaries of optical fibers: from photonics to optogenetics and environmental monitoring
• Grantee: Younes Messaddeq
• Support Opportunities: Research Projects - SPEC Program