| Full text | |
| Author(s): |
Soares, Mario R. S.
;
Goncalves, Ricardo H.
;
Nogueira, Icamira C.
;
Bettini, Jefferson
;
Chiquito, Adenilson J.
;
Leite, Edson R.
Total Authors: 6
|
| Document type: | Journal article |
| Source: | Physical Chemistry Chemical Physics; v. 18, n. 31, p. 21780-21788, AUG 31 2016. |
| Web of Science Citations: | 12 |
| Abstract | |
Hematite is considered to be the most promising material used as a photoanode for water splitting and here we utilized a sintered hematite photoanode to address the fundamental electrical, electrochemical and photoelectrochemical behavior of this semiconductor oxide. The results presented here allowed us to conclude that the addition of Sn4+ decreases the grain boundary resistance of the hematite polycrystalline electrode. Heat treatment in a nitrogen (N-2) atmosphere also contributes to a decrease of the grain boundary resistance, supporting the evidence that the presence of oxygen is fundamental for the formation of a voltage barrier at the hematite grain boundary. The N-2 atmosphere affected both doped and undoped sintered electrodes. We also observed that the heat treatment atmosphere modifies the surface states of the solid-liquid interface, changing the charge-transfer resistance. A two-step treatment, with the second being performed at a low temperature in an oxygen (O-2) atmosphere, resulted in a better solid-liquid interface. (AU) | |
| FAPESP's process: | 13/07296-2 - CDMF - Center for the Development of Functional Materials |
| Grantee: | Elson Longo da Silva |
| Support Opportunities: | Research Grants - Research, Innovation and Dissemination Centers - RIDC |