Construction of hierarchical cobalt-molybdenum selenide hollow nanospheres architectures for high performance battery-supercapacitor hybrid devices

Controlled Selenium Infiltration of Cobalt Phosphide Nanostructure Arrays from a Two-Dimensional Cobalt Metal–Organic Framework: A Self-Supported Electrode for Flexible Quasi-Solid-State Asymmetric Supercapacitors

“…Figure c shows that the two peaks for Co 2p 3/2 and Co 2p 1/2 (related to Co 3+ ) are located at binding energies of 778.5 and 793.6 eV, respectively, and correspond to Co and P bonding. , Two additional peaks for Co 2p 3/2 and Co 2p 1/2 at 780.3 and 796.8 eV, respectively (related to Co 2+ ) correspond to Co–Se bonding. The satellite peaks located at 784.7 and 802.3 eV are related to the shakeup excitation with low intensity related to Co 2p 3/2 and Co 2p 1/2 of Se 0.6 @CPNA-ACFT, respectively. ,, Compared with the reported values for Co and Se in binary CoSe 2 , these results show slight changes due to the assimilation of the P element in the same material. ,, Furthermore, individual peaks corresponding to Co 2p 3/2 (779.1 and 780.8, 778.5 and 780.2, and 778.6 and 780.1 eV) and Co 2p 1/2 (793.6 and 796.3, 793.6 and 796.6, and 793.6 and 796.5 eV) are related to CPNA-ACFT, Se 0.3 @CPNA-ACFT, and Se 0.9 @CPNA-ACFT and are shown in Figure S9c 1 ,c 3 ,c 4 , respectively. From the above results, it is clearly seen that the Co 2+ 2 p 3/2 XPS peak from Se x @CPNA-ACFT ( x = 0.3, 0.6, and 0.9) shifted negatively compared to the respective XPS peak from CPNA-ACFT, indicating substantial electron transfer and robust bond between Co and Se .…”

“…From the above results, it is clearly seen that the Co 2+ 2 p 3/2 XPS peak from Se x @CPNA-ACFT ( x = 0.3, 0.6, and 0.9) shifted negatively compared to the respective XPS peak from CPNA-ACFT, indicating substantial electron transfer and robust bond between Co and Se . At the same time, it was observed that Co carries a partial positive charge (δ + ) and P and Se both carry a partial negative charge (δ – ), and consequently, a small electron density is transferred from Co to P and Se by enhancing the number of active sites and increasing the ion transport kinetics during the electrochemical activity. ,, The XPS data shown in Figure and Figure S9 validate the successful phosphidization and selenium infiltration of 2D Co-MOF into Se x @CPNA, but not all cobalt in the cobalt phosphide was converted into cobalt diselenide. Hence, Se-infiltrated CPNA showed enhanced electrochemical behavior due to the dual active centers CoP and CoSe 2 .…”

“…A Ni 0.6 Co 0.4 Se 2 -based ASC shows an energy density of 44.1 Wh kg –1 at a power density of 691.3 W kg –1 . Hierarchical hollow CoSe 2 /MoSe 2 nanospheres and activated carbon (AC) with a CC-based ASC provide an energy density of 51.84 Wh kg –1 at a power density of 799.2 W kg –1 . An ASC comprising CC-based 3D Co-MOF-derived Co/CoP-decorated nanoporous carbon polyhedra and AC demonstrated an energy density of 39.2 Wh kg –1 at a power density of 1960 W kg –1 .…”

“…2+ ) correspond to Co−Se bonding. The satellite peaks located at 784.7 and 802.3 eV are related to the shakeup excitation with low intensity related to Co 2p 3/2 and Co 2p 1/2 of Se 0.6 @ CPNA-ACFT, respectively 55,61,65. Compared with the reported values for Co and Se in binary CoSe 2 , these results show slight changes due to the assimilation of the P element in the same material 55,57,61.…”

“…The satellite peaks located at 784.7 and 802.3 eV are related to the shakeup excitation with low intensity related to Co 2p 3/2 and Co 2p 1/2 of Se 0.6 @ CPNA-ACFT, respectively 55,61,65. Compared with the reported values for Co and Se in binary CoSe 2 , these results show slight changes due to the assimilation of the P element in the same material 55,57,61. Furthermore, individual peaks corresponding to Co 2p 3/2 (779.1 and 780.8, 778.5 and 780.2, and 778.6 and 780.1 eV) and Co 2p 1/2 (793.6 and 796.3, 793.6 and 796.6, and 793.6 and 796.5 eV) are related to CPNA-ACFT, Se 0.3 @…”