Superior Performance\nof 2D Layered Bimetallic Bismuth\nand Copper Oxytellurides for Supercapacitor Applications

Widespread applications of 2D metal oxychalcogenide materials\nin\nthe fields of semiconductors, thermoelectrics, and optoelectronics\nhave raised the interest of the research community to explore more\nabout these materials. The addition of metals and the preparation\nof different combinations of composite materials can effectively raise\ntheir utility. Here, the synthesis of bismuth (Bi)- and copper (Cu)-based\nlayered oxytelluride materials is performed using the “microwave\nmethod” at a fixed power of 540 W and an irradiation time of\n20 min. Good crystalline phases of the synthesized materials are obtained\nfrom the crystallographic studies, which agree well with the reported\nstudies done previously. Morphological studies show the appearance\nof nanosheet-like structures in different synthesized samples. The\nRaman spectra of the samples demonstrate several vibrational modes.\nChemical analysis confirms the valence states of the individual elements.\nThe synthesized bismuth oxytelluride (BOT), copper oxytelluride (COT),\nand bismuth copper oxytelluride (BCOT) samples are investigated for\nsupercapacitor applications. The electrochemical capacitive performance\nof BOT, COT, and BCOT is studied in the potential range of 0–0.6\nV in an aqueous 2 M KOH electrolyte. While BOT and COT exhibit only\n95 F g<sup>–1</sup> (57 C g<sup>–1</sup>) and 158 F\ng<sup>–1</sup> (94.8 C g<sup>–1</sup>), respectively,\nBCOT can provide a higher specific capacitance of 323 F g<sup>–1</sup> (193.8 C g<sup>–1</sup>) at a specific current of 2 A g<sup>–1</sup>, with excellent cycling stability of 90.5% after\ncontinuous 5000 cycles. Thus, this study emphasizes the better capacitive\nperformance of bimetallic oxychalcogenides over monometallic oxychalcogenides.