[1] [1] H.B. Wu, H.H. Hng and X.W. Lou, Adv. Mater. 24, 2567 (2012).

[2] [2] X. Xu, C. Randorn, P. Efstathiou and J.T.S. Irvine, Nat. Mater. 11, 595 (2012).

[3] [3] D.J. Martin, G. Liu, S.J.A. Moniz, Y. Bi, A.M. Beale, J. Ye and J. Tang, Chem. Soc. Rev. 44, 7808 (2015).

[4] [4] D.J. Martin, N. Umezawa, X. Chen, J. Ye and J. Tang, Energy Environ. Sci. 6, 3380 (2013).

[5] [5] T.W. Kim and K.S. Choi, Science 343, 990 (2014).

[6] [6] C. Du, X. Yang, M.T. Mayer, H. Hoyt, J. Xie, G. McMahon, G. Bischoping and D. Wang, Angew. Chem. Int. Ed. 52, 12692 (2013).

[7] [7] A. Samal, D. P. Das, K. K. Nanda, B. K. Mishra, J. Das and A. Dah, Chem-Asian J. 11, 584 (2015).

[8] [8] S. Wan, M. Ou, Q. Zhong and S. Zhang, New J. Chem. 42, 318 (2018).

[9] [9] Y. Bi, H. Hu, S. Ouyang, G. Lu, J. Cao and J. Ye, Chem. Commun. 48, 3748 (2012).

[10] [10] Y. Lin, Y. Hsu, Y. Chen, S. Wang, J. T. Miller, L. Chen and K. Chen, Energy Environ. Sci. 5, 8917 (2012).

[11] [11] Q. Wu, P. Diao, J. Sun, D. Xu, T. Jin and M. Xiang, J. Mater. Chem. A 3, 18991 (2015).

[12] [12] S. Zhang, X. Gu, Y. Zhao and Y. Qiang, Mater. Sci. Eng. B 201, 57 (2015).