1. Synergy of nitrogen dopants and cobalt single atoms in calcium niobate nanosheets for photocatalytic oxygen evolution
- Author
-
Sajjad ul Haq, Chung-Li Dong, Yu-Cheng Huang, Rana Moiz ur Rehman, Essossimna Djatoubai, Zhi Lin, Muhammad Shuaib Khan, and Shaohua Shen
- Subjects
cobalt single atoms ,nitrogen doping ,2D perovskite oxide ,photocatalysis ,O2 evolution ,Production of electric energy or power. Powerplants. Central stations ,TK1001-1841 ,Renewable energy sources ,TJ807-830 - Abstract
The successful separation of photoexcited charge carriers and their effective utilization are crucial for overcoming the slow kinetics of the four-electron process for photocatalytic oxygen evolution. Herein, a novel strategy utilizing urea as a source of N-doping on Ca _2 Nb _3 O _10 nanosheets is adopted, followed by the successful deposition of Co single atoms (Co-SAs) to achieve a synergistic effect. The presence of N-dopants and Co-SAs is validated via various experimental techniques. It is also observed that the presence of N-doping contributed towards the deposition of higher content of Co-SAs (0.21 wt%) in Ca _2 Nb _3 O _10− _x N _x -Co _SA nanosheets compared to 0.15 wt% for non-doped Ca _2 Nb _3 O _10 -Co _SA . The optimized Ca _2 Nb _3 O _10− _x N _x -Co _SA nanosheets exhibited an impressive photocatalytic O _2 evolution of ∼727.22 µ mol g ^−1 h ^−1 via the synergy of N-dopants and Co-SAs. As a result, the O _2 evolution response of Ca _2 Nb _3 O _10− _x N _x -Co _SA is 3.6 times higher than that of pristine Ca _2 Nb _3 O _10 nanosheets (201.26 µ mol g ^−1 h ^−1 ), 2.24 times better than Ca _2 Nb _3 O _10− _x N _x nanosheets (323.42 µ mol g ^−1 h ^−1 ), and 1.77 times higher compared to Ca _2 Nb _3 O _10 -Co _SA , (409.33 µ mol g ^−1 h ^−1 ), which clearly demonstrated the synergistic effect of N-dopants and Co-SAs in Ca _2 Nb _3 O _10− _x N _x -Co _SA nanosheets. Based on the findings of various characterization techniques, the co-presence of N-dopants and Co-SAs is observed to contribute towards better charge carrier separation, and utilization to achieve superior photocatalytic response. Thus, this study presents a novel approach for incorporating N-dopants and Co-SAs on Ca _2 Nb _3 O _10 nanosheets, which can be extended to a wide range of nanosheets produced by the soft chemical exfoliation method.
- Published
- 2024
- Full Text
- View/download PDF