XPS investigation of MnO2 deposits functionalized with graphitic carbon nitride

Composite materials based on MnO2 deposits functionalized with graphitic carbon nitride (gCN) nanostructures are promising (photo)electrocatalystsfor oxygen evolution reaction (OER). Besides the individual properties of the two electrode components, mutual interactions attheir interface can also exert a significant influence on functional performances. In this work, MnO2 deposits are synthesized by plasmaenhanced-chemical vapor deposition on Ni foam supports and subsequently decorated with two different forms of carbon nitride via electrophoreticdeposition. Structural and morphological analyses revealed the formation of beta-MnO2 2D structures hierarchically assembledinto flowerlike architectures, whose surface appeared decorated by 3D particles built up from gCN nanoflakes. Based on the intimatecontact between the two semiconductors, an effective electronic and chemical coupling was established at their interface. In the following,we report on a comparative XPS characterization of a bare MnO2 electrode material and of two MnO2-gCN composite systems preparedfrom different carbon nitride powders. Survey spectra as well as detailed scans for C 1s, N 1s, O 1s, and Mn 2p regions are presented andcritically discussed.