Shell-core MoS2 nanosheets@Fe3O4 sphere heterostructure with exposed active edges for efficient electrocatalytic hydrogen production.

Rational design and constructing advanced materials with intriguing nanostructures towards highly efficient and sustainable energy conversion and storage have received focused research efforts, but exploring effective strategies to accomplish this mission is still challenging. Aiming at this goal, we construct MoS 2 nanosheets on Fe 3 O 4 nanospheres via a SiO 2 shell assisted sacrifice template method for the first time. The shell-core structured MoS 2 @Fe 3 O 4 catalyst is well characterized by XRD, Raman, TEM, SEM, and XPS techniques. SEM and TEM show that MoS 2 nanosheets possess edge exposed feature and defect-rich structure, assuring the maximum active sites for electrochemical hydrogen evolution reaction (HER). Raman characterization reveals the chemical coupling between MoS 2 and Fe 3 O 4 , indicating the formation of MoS 2 @Fe 3 O 4 heterostructure at the shell-core interface. High-resolution TEM (HRTEM) shows abundant defects at the heterostructures, which supplies more catalytic sites. The improved catalytic sites are proved by electrochemical capacitance measurements, and the enhanced catalytic activity over each site is also probed. Therefore, MoS 2 @Fe 3 O 4 exhibits remarkably enhanced catalytic activity for water splitting due to the above mentioned benefits. [ABSTRACT FROM AUTHOR]