Journal Article

Enhancing Water-Splitting Efficiency Using a Zn/Sn-Doped PN Photoelectrode of Pseudocubic α-Fe2O3 Nanoparticles

Tung-Ming, Lin, Hsiang-Chiu, Wu, Wei-Hsuan, Hung, Jie-Xiang, Yang, Yan-Kai, Huang, Meng Yongtao, Chuan-Ming, Tseng, Jin-Pei, Deng, Yang-Ming, Wang

2020

Overview

α-Phase hematite photoelectrodes can split water. This material is nontoxic, inexpensive, and chemically stable; its low energy gap of 2.3 eV absorbs light with wavelengths lower than 550 nm, accounting for approximately 30% of solar energy. Previously, we reported polyhedral pseudocubic α-Fe2O3 nanocrystals using a facile hydrothermal route to increase spatial charge separation, enhancing the photocurrent of photocatalytic activity in the water-splitting process. Here, we propose a p-n junction structure in the photoanode of pseudocubic α-Fe2O3 to improve short carrier diffusion length, which limits its photocatalytic efficiency. We dope Zn on top of an Fe2O3 photoanode to form a layer of p-type semiconductor material; Sn is doped from the FTO substrate to form a layer of n-type semiconductor material. The p-n junction, n-type Fe2O3:Sn and p-type Fe2O3:Zn, increase light absorption and charge separation caused by the internal electric field in the p-n junction.

• Publisher: Springer Nature B.V
• Subject: Catalytic activity / Chromatography / Diffusion length / Efficiency / Electric fields / Electrodes / Electrolytes / Electromagnetic absorption / Electron microscopes / Energy gap / Ethanol / Ferric oxide / Hematite / N-type semiconductors / Nanocrystals / Nanoparticles / P-n junctions / P-type semiconductors / Photoanodes / Photocatalysis / Photoelectric effect / Photoelectric emission / Semiconductor materials / Separation / Solar energy / Spectrum analysis / Splitting / Substrates / Water / Water splitting / Wavelengths / Zinc