After sample preparation as described in the Experimental Section and the SI (Supporting Information), the phase purity and crystallinity of the BiVO4 photoanodes was analyzed by powder X-ray diffraction (pXRD) (Figure , Supporting Information). All diffraction peaks can be indexed to monoclinic scheelite BiVO4 (JCPDS card Number 14-0688) and to the FTO support. No crystalline impurities (such as V2O5) were detected. Moreover, no diffraction peaks associated with the CoPOM compound are observed. These observations highlight that the reported synthetic approach leads to thin-film BiVO4 photoanodes, whereby the doping and surface-modification with CoPOM does not significantly alter the crystal lattice of the resulting system. , Supporting Information). The Sn signal is due to the use of fluorine-doped tin oxide (FTO) as a conductive transparent support. The deconvoluted Bi 4f and V 2p spectra show the characteristic peaks for Bi 3+ (at 164.9 eV and 159.6 eV for Bi 4f5/2 and Bi 4f7/2, respectively) and V 5+ (at 522.7 eV for V 2p1/2 and 515.2 eV for V 2p3/2) expected for BiVO4 (Figure and S2c, Supporting Information). In the O 1s spectrum, the two characteristic peaks located at 528.3 eV and 529.5 eV (Figure , Supporting Information) are assigned to lattice oxygen in bismuth vanadate and surface hydroxyl oxygen, respectively. Compared with pristine BiVO4 , the Bi 4f, V 2p and O 1s peaks of Composite 1 are shifted to higher binding energies by 0.1 eV, 0.4 eV, and 0.4 eV, respectively (Figure , Supporting Information). This can be explained by interactions of dopant elements (Co 3+ , W 6+ , see below XPS analysis) from CoPOM with Bi, V and O atoms. The slight shifts are expected due to the higher chargedensities of the dopants (W 6+ >V 5+ , Co 3+ >Bi 3+ ). These data support the successful incorporation of the CoPOM components (W 6+ , Co 3+ ) into the BiVO4 lattice. Note that similar shifts in binding energies are observed for the Composite 3 reference photoanode (Figure , Supporting Information).