Freeing the Polarons to Facilitate Charge Transport in BiVO4 from Oxygen Vacancies with an Oxidative 2D Precursor

Weitao Qiu; Shuang Xiao; Jingwen Ke; Zheng Wang; Songtao Tang; Kai Zhang; Wei Qian; Yongchao Huang; Duan Huang; Yexiang Tong; Shihe Yang

doi:10.1002/anie.201912475

Freeing the Polarons to Facilitate Charge Transport in BiVO₄ from Oxygen Vacancies with an Oxidative 2D Precursor

Angew Chem Int Ed Engl. 2019 Dec 19;58(52):19087-19095. doi: 10.1002/anie.201912475. Epub 2019 Nov 8.

Authors

Weitao Qiu^{1

2}, Shuang Xiao¹, Jingwen Ke¹, Zheng Wang¹, Songtao Tang^{1

2}, Kai Zhang¹, Wei Qian¹, Yongchao Huang³, Duan Huang², Yexiang Tong², Shihe Yang^{1

4}

Affiliations

¹ Guangdong Provincial Key Lab of Nano-Micro Materials Research, School of Chemical Biology and Biotechnology, Shenzhen Graduate School, Peking University, Shenzhen, 518055, China.
² MOE of the Key Laboratory of Bioinorganic and Synthetic Chemistry, KLGHEI of Environment and Energy Chemistry, The Key Lab of Low-Carbon Chemistry & Energy Conservation of Guangdong Province, School of Chemistry, Sun Yat-sen University, Guangzhou, 510275, China.
³ Research Institute of Environmental Studies at Greater Bay Key Laboratory for Water Quality and Conservation of the Pearl River Delta Ministry of Education, School of Environmental Science and Engineering, Guangzhou University, Guangzhou, 510006, China.
⁴ Department of Chemistry, The Hong Kong University of Science and Technology, Hong Kong, China.

PMID: 31617959
DOI: 10.1002/anie.201912475

Abstract

The BiVO₄ photoelectrochemical (PEC) electrode in tandem with a photovoltaic (PV) cell has shown great potential to become a compact and cost-efficient device for solar hydrogen generation. However, the PEC part is still facing problems such as the poor charge transport efficiency owing to the drag of oxygen vacancy bound polarons. In the present work, to effectively suppress oxygen vacancy formation, a new route has been developed to synthesize BiVO₄ photoanodes by using a highly oxidative two-dimensional (2D) precursor, bismuth oxyiodate (BiOIO₃ ), as an internal oxidant. With the reduced defects, namely the oxygen vacancies, the bound polarons were released, enabling a fast charge transport inside BiVO₄ and doubling the performance in tandem devices based on the oxygen vacancy eliminated BiVO₄ . This work is a new avenue for elaborately designing the precursor and breaking the limitation of charge transport for highly efficient PEC-PV solar fuel devices.

Keywords: bismuth vanadate; oxygen vacancies; perovskite solar cells; photoelectrochemical water splitting; polaron hopping.

Abstract

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