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(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

Hematite Surface Activation by Chemical Addition of Tin Oxide Layer

Full text
Author(s):
Carvalho, Jr., Waldemir M. ; Souza, Flavio L.
Total Authors: 2
Document type: Journal article
Source: ChemPhysChem; v. 17, n. 17, p. 2710-2717, SEP 5 2016.
Web of Science Citations: 5
Abstract

In this study, the effect of tin (Sn4+) modification on the surface of hematite electrodes synthesized by an aqueous solution route at different times (2, 5, 10, 18, and 24h) is investigated. As confirmed from X-ray diffraction results, the as-synthesized electrode exhibits an oxyhydroxide phase, which is converted into a pure hematite phase after being subjected to additional thermal treatment at 750 degrees C for 30min. The tin-modified hematite electrode is prepared by depositing a solution of Sn4+ precursor on the as-synthesized electrode, followed by thermal treatment under the same abovementioned conditions. This modification results in an enhancement of the photocurrent response for all hematite electrodes investigated and attains the highest values of around 1.62 and 2.3mAcm(-2) at 1.23 and 1.4V versus RHE, respectively, for electrodes obtained in short synthesis times (2h). Contact angle measurements suggest that the deposition of Sn4+ on the hematite electrode provides a more hydrophilic surface, which favors a chemical reaction at the interface between the electrode and electrolyte. This result generates new perspectives for understanding the deposition of Sn4+ on the hematite electrode surface, which is in contrast with several studies previously reported; these studies state that the enhancement in photocurrent density is related to either the induction of an increased donor charge density or shift in the flat-band potential, which favors charge separation. (AU)

FAPESP's process: 14/50516-6 - Enhancing performance of artificial photosynthesis by engineered nanomaterials and photon management
Grantee:Flavio Leandro de Souza
Support type: Regular Research Grants
FAPESP's process: 13/05471-1 - Effect of dopants in semiconductor nanostructures and their impact on photocatalytic performance
Grantee:Waldemir Moura de Carvalho Junior
Support type: Scholarships in Brazil - Doctorate
FAPESP's process: 13/07296-2 - CDMF - Center for the Development of Functional Materials
Grantee:Elson Longo da Silva
Support type: Research Grants - Research, Innovation and Dissemination Centers - RIDC
FAPESP's process: 11/19924-2 - Study and development of advanced novel materials: electronic, magnetic and nanostructured: an interdisciplinary approach
Grantee:Carlos Rettori
Support type: Research Projects - Thematic Grants