Synergy of nitrogen dopants and cobalt single atoms in calcium niobate nanosheets for photocatalytic oxygen evolution
Sajjad ul Haq,
Chung-Li Dong,
Yu-Cheng Huang,
Rana Moiz ur Rehman,
Essossimna Djatoubai,
Zhi Lin,
Muhammad Shuaib Khan,
Shaohua Shen
Affiliations
Sajjad ul Haq
International Research Center for Renewable Energy (IRCRE), State Key Laboratory of Multiphase Flow in Power Engineering (MPFE), Xi’an Jiaotong University , No. 28 Xianning West Street, Xi’an 710049, People’s Republic of China
Chung-Li Dong
Department of Physics, Tamkang University , 151 Yingzhuan Road, New Taipei City 25137, Taiwan
Yu-Cheng Huang
Department of Physics, Tamkang University , 151 Yingzhuan Road, New Taipei City 25137, Taiwan
Rana Moiz ur Rehman
International Research Center for Renewable Energy (IRCRE), State Key Laboratory of Multiphase Flow in Power Engineering (MPFE), Xi’an Jiaotong University , No. 28 Xianning West Street, Xi’an 710049, People’s Republic of China
Essossimna Djatoubai
International Research Center for Renewable Energy (IRCRE), State Key Laboratory of Multiphase Flow in Power Engineering (MPFE), Xi’an Jiaotong University , No. 28 Xianning West Street, Xi’an 710049, People’s Republic of China
Zhi Lin
International Research Center for Renewable Energy (IRCRE), State Key Laboratory of Multiphase Flow in Power Engineering (MPFE), Xi’an Jiaotong University , No. 28 Xianning West Street, Xi’an 710049, People’s Republic of China
Muhammad Shuaib Khan
International Research Center for Renewable Energy (IRCRE), State Key Laboratory of Multiphase Flow in Power Engineering (MPFE), Xi’an Jiaotong University , No. 28 Xianning West Street, Xi’an 710049, People’s Republic of China
International Research Center for Renewable Energy (IRCRE), State Key Laboratory of Multiphase Flow in Power Engineering (MPFE), Xi’an Jiaotong University , No. 28 Xianning West Street, Xi’an 710049, People’s Republic of China
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.
