Hafnium boosts charge carrier dynamics in hematite for improved solar water splitting

Author(s)

Morishita, Gustavo M. ; Rodriguez-Gutierrez, Ingrid ; Castro, Ricardo H. R. ; Souza, Flavio L.

• Document type: Journal article
• Source: Materials Letters; v. 340, p. 4-pg., 2023-03-10.

Abstract

The work demonstrates a three-fold increase in photoelectrochemical efficiency of hematite nanorods as a result of the combination of Hafnium surface doping and the incorporation of a ZrO2 underlayer on FTO. While the ZrO2 layer reduced the electron loss from the back-injection into the FTO contact support, Hafnium surface doping did not significantly alter the hematite lattice structure. But rather, Hafnium induced nanorod diameter reduction from 32 +/- 2 and 26 +/- 2 nm, with a consequent increase in the active surface area. The linear sweep voltammetry measurements with 100 mW cm-2 illumination in a 500 nm photoanode thickness showed a photocurrent density of 2.07 mA cm-2 at 1.23 V in a reversible hydrogen electrode (RHE). The value contrasts with the bare hematite rods (0.75 mA cm-2), highlighting the photoanode design's role in improving solar power hydrogen production. (AU)

• FAPESP's process: 17/02317-2 - Interfaces in materials: electronic, magnetic, structural and transport properties
• Grantee: Adalberto Fazzio
• Support Opportunities: Research Projects - Thematic Grants
• FAPESP's process: 17/11986-5 - Generation and storage of New Energy: bringing technological development for the country
• Grantee: Ana Flávia Nogueira
• Support Opportunities: Research Grants - Research Centers in Engineering Program
• 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