A Pacman‐Like Titanium‐Doped Cobalt Sulfide Hollow Superstructure for Electrocatalytic Oxygen Evolution
Tong Bao, Yi Xia, Jingyi Lu, Chaoqi Zhang, Jing Wang, Ling Yuan, Yunxia Zhang, Chao Liu, Chengzhong Yu
Abstract
Abstract Transition‐metal sulfides (TMSs) are attractive oxygen evolution reaction (OER) electrocatalysts. Developing new strategies to improve their electrochemical performance of TMSs is of great significance. Herein, a unique pacman‐like titanium‐doped cobalt sulfide hollow superstructure (Ti‐CoSx HSS) is fabricated as an OER electrocatalyst. Using a prearranged metal–organic framework (MOF)‐on‐MOF heterostructure as a precursor treated by one‐pot sulfidation, a sequential structural conversion process leads to the formation of Ti‐CoSx HSS, which is assembled by interconnected Ti‐doped CoSx nanocages around a cake‐like cavity. Benefiting from the architecture and compositional advantages, Ti‐CoSx HSS exhibits excellent OER performance with an overpotential of 249 mV at 10 mA cm −2 and Tafel slope of 45.5 mV dec −1 due to increased active site exposure, enhanced electron and mass transfer. This strategy enabled by MOF‐on‐MOF paves the way toward innovative MOF derivatives for various applications.