Hydrothermal Synthesized CoS2 as Efficient Co-Catalyst to Improve the Interfacial Charge Transfer Efficiency in BiVO4

Yangqin Gao; Guoqing Yang; Zhijie Tian; Hongying Zhu; Lianzheng Ma; Xuli Li; Ning Li; Lei Ge

doi:10.3390/inorganics10120264

Inorganics (Dec 2022)

Hydrothermal Synthesized CoS2 as Efficient Co-Catalyst to Improve the Interfacial Charge Transfer Efficiency in BiVO4

Yangqin Gao,
Guoqing Yang,
Zhijie Tian,
Hongying Zhu,
Lianzheng Ma,
Xuli Li,
Ning Li,
Lei Ge

Affiliations

Yangqin Gao: Department of Materials Science and Engineering, College of New Energy and Materials, China University of Petroleum Beijing, No. 18 Fuxue Rd., Beijing 102249, China
Guoqing Yang: Department of Materials Science and Engineering, College of New Energy and Materials, China University of Petroleum Beijing, No. 18 Fuxue Rd., Beijing 102249, China
Zhijie Tian: Department of Materials Science and Engineering, College of New Energy and Materials, China University of Petroleum Beijing, No. 18 Fuxue Rd., Beijing 102249, China
Hongying Zhu: Department of Materials Science and Engineering, College of New Energy and Materials, China University of Petroleum Beijing, No. 18 Fuxue Rd., Beijing 102249, China
Lianzheng Ma: Department of Materials Science and Engineering, College of New Energy and Materials, China University of Petroleum Beijing, No. 18 Fuxue Rd., Beijing 102249, China
Xuli Li: Department of Materials Science and Engineering, College of New Energy and Materials, China University of Petroleum Beijing, No. 18 Fuxue Rd., Beijing 102249, China
Ning Li: Department of Materials Science and Engineering, College of New Energy and Materials, China University of Petroleum Beijing, No. 18 Fuxue Rd., Beijing 102249, China
Lei Ge: Department of Materials Science and Engineering, College of New Energy and Materials, China University of Petroleum Beijing, No. 18 Fuxue Rd., Beijing 102249, China

DOI: https://doi.org/10.3390/inorganics10120264
Journal volume & issue: Vol. 10, no. 12
p. 264

Abstract

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The bare surface of BiVO4 photoanode usually suffers from extremely low interfacial charge transfer efficiency which leads to a significantly suppressed photoelectrochemical water splitting performance. Various strategies, including surface modification and the loading of co-catalysts, facilitate the interface charge transfer process in BiVO4. In this study, we demonstrate that CoS2 synthesized from the hydrothermal method can be used as a high-efficient co-catalyst to sufficiently improve the interface charge transfer efficiency in BiVO4. The photoelectrochemical water splitting performance of BiVO4 was significantly improved after CoS2 surface modification. The BiVO4/CoS2 photoanode achieved an excellent photocurrent density of 5.2 mA/cm2 at 1.23 V versus RHE under AM 1.5 G illumination, corresponding to a 3.7 times enhancement in photocurrent compared with bare BiVO4. The onset potential of the BiVO4/CoS2 photoanode was also negatively shifted by 210 mV. The followed systematic combined optical and electrochemical characterization results reveal that the interfacial charge transfer efficiency of BiVO4 was largely improved from less than 20% to more than 70% due tor CoS2 surface modification. The further surface carrier dynamics study performed using an intensity modulated photocurrent spectroscopy displayed a 6–10 times suppression in surface recombination rate constants for CoS2 modified BiVO4, which suggests that the key reason for the improved interfacial charge transfer efficiency possibly originates from the passivated surface states due to the coating of CoS2.

Published in Inorganics

ISSN: 2304-6740 (Online)
Publisher: MDPI AG
Country of publisher: Switzerland
LCC subjects: Science: Chemistry: Inorganic chemistry
Website: http://www.mdpi.com/journal/Inorganics

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