Optimizing the Oxygen Vacancies Concentration of Thin NiO Nanosheets for Efficient Selective CO2 Photoreduction. Issue 12 (9th November 2021)

• Record Type: Journal Article
• Authors: Xiang, Junxiang; Zhang, Tingshi; Cao, Ruodan; Lin, Mingxiong; Yang, Bixia; Wen, Yonglin; Zhuang, Zanyong; Yu, Yan
• Is Part Of: Solar RRL. Volume 5:Issue 12(2021)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2021-11-09
• Subjects: 2D materials -- defect engineering -- oxygen vacancies concentration -- photocatalysis -- selective CO2 reduction; Solar energy -- Periodicals; Photovoltaic power generation -- Periodicals; Solar energy -- Research -- Periodicals; Photovoltaic power generation -- Research -- Periodicals; Periodicals; 333.7923
• DOI: 10.1002/solr.202100703
• Languages: English
• ISSNs: 2367-198X

Abstract

Abstract : In designing highly efficient CO2 reduction reaction (CRR) photocatalysts with excellent selectivity and efficiency, a key limitation is the poor understanding on the mechanism response of the active sites of catalysts to CRR selectivity and activity. Herein, it is revealed how the concentration of point defect affects the CRR selectivity and activity of catalysts. Quasi‐2D NiO nanosheets (NSs) that are composed of NiO nanoparticles (NPs), and finely tuned the oxygen vacancies (OVs) concentration of the NSs by regulating the grain size (≈5–25 nm) of NPs are created. The NiO with moderate OVs concentration has the highest photocatalytic CRR efficiency and selectivity ( V CO = 17.2 μmol h −1, 98.3%), outperforming other prepared NiO catalysts and reported Ni‐based photocatalysts. Density functional theory calculation associated with the CO2 temperature‐programmed desorption confirms that the moderate OVs concentration enables strong CO2 binding to promote CO2 adsorption and activation and allows efficient charge transfer. In contrast, excessive OVs reduce the CO2 binding affinity and restrain charge mobility, both detrimental to the CRR performance. Abstract : It is demonstrated that the defect concentration determines the CO2 reduction reaction (CRR) selectivity and efficiency of catalysts. The moderate oxygen vacancies (OVs) concentration enables strong CO2 binding to promote CO2 adsorption and activation and allows efficient charge transfer. Excessive OVs reduce the CO2 binding affinity and restrain charge mobility, both detrimental to the CRR performance.