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[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]

CdS-PVP nanocomposites grown with various concentrations of Cd + /S − and PVP are studied using Raman and atomic force microscopy mapping on same selected areas. The study shows that CdS nanocrystals are embedded in either a thin-film or spheres of PVP, formation of which depends on relative ratio of Cd + /S − concentration (density of nanocrystals) to PVP. Collapse of PVP from planer matrix to the sphere morphology is correlated with high density of CdS nanocrystals and the attractive interaction between CdS nanocrystals and PVP polymer leading to a co-operative growth mechanism. The understanding developed can be used to control the growth of CdS-PVP nanocomposites with desired properties for optoelectronic device applications. [ABSTRACT FROM AUTHOR]

Raman and atomic force microscopy (AFM) mapping on the same selected area are used to get unique information about the morphology of Si nanocrystals (NCs) embedded in SiO 2 , which is difficult to obtain by any other conventional technique. The sensitivity of Raman spectroscopy to surface/interface and confinement effects in NCs is effectively used to correlate the Raman intensity profile in Raman mapping with the topography obtained from AFM to understand that Si NCs are clustered in i) smaller clusters (∼100 nm) organized closely in two dimensions (2D) and ii) big (∼2 μm) three dimensional (3D) isolated clusters, although the growth is carried out to be multilayer (Si/SiO 2 ). Raman mapping performed by varying the focal spot along the depth shows stacking of larger (>∼60 Å) to smaller sizes (<∼40 Å) Si NCs from bottom to top for some clusters. To understand the observed morphologies, further study of specially grown Si–SiO 2 nanocomposites is performed, which suggest formation of smaller Si NCs at the top due to annealing at 800 °C in Si rich SiO 2 and possible existence of thermal gradient in an insulating matrix of SiO 2. Larger Si NCs are formed in the laser induced plume (plasma) itself. [ABSTRACT FROM AUTHOR]