Bi2S3 nanorods modified with Co(OH)2 ultrathin nanosheets to significantly improve its pseudocapacitance for high specific capacitance

Nanostructured Bi2S3 has been used in various energy conversion and storage systems, but it alone does not possess significant capacitance and this has never been investigated. A modification at the nanoscale is used to create a structure composed of Bi2S3 nanorods and alpha-Co(OH)(2) nanosheets, which is controllably synthesized by a facile seed-layer assisted hydrothermal method to produce the former followed by electrochemical deposition of the latter. The Co(OH)(2)-modified Bi2S3 nanorods significantly boost the pseudocapacitance of Bi2S3 for high specific capacitance, while improving the cycle life stability. Results reveal that the controlled Co(OH)(2) modification process promotes a networked, highly porous structure for a considerably larger surface allowing the electrolyte-access; thus, enhancing the pseudocapacitance and resulting in a high specific capacitance.