Unraveling compensation between electron transfer and strain in Ni-Ag-MoS2 photocatalyst.

[Display omitted] • X-PEEM and Raman mapping are used to probe interfaces in Ni-Ag-MoS 2 heterostructure. • Higher H 2 yield of Ni-Ag-MoS 2 evidence successful bonding of Ni, Ag and MoS 2. • Downshift due to charge injection and upshift due to strain is noted in phonons. • Ag intercalated MoS 2 , its non-uniform growth, and intimate contact with MoS 2 is noted. • Electronic coupling and strain can tune the electromechanical properties of MoS 2. Despite the boom in catalytic response via constructing interfaces, understanding interfaces' interaction in heterostructures is still a paradox. In this work, the interaction of Ni with MoS 2 in Ni-Ag-MoS 2 heterostructure are unveiled through synchrotron X-PEEM and what's more, the missing interaction mechanism at the Ag-MoS 2 interface is probed via Raman mapping. The observed competition between the downshift of the E 2g 1 and A 1g modes due to charge carrier injection and the upshift of the E 2g 1 and A 1g modes due to compressive strain during reverse laser power experiment is assigned to the non-uniform growth of Ag nanoparticles, their intimate contact with MoS 2 , and Ag intercalated layered MoS 2. The substantial improvement of the H 2 yield of the Ni-Ag-MoS 2 (∼55 μmol h−1 g−1) over the pristine MoS 2 and the binary Ag-MoS 2 evidence successful bonding of Ni, Ag and MoS 2. This study highlights the importance of considering both electronic coupling and strain to optically tune electromechanical properties of MoS 2. [ABSTRACT FROM AUTHOR]