Carbon Dots-Decorated Bi2WO6 in an Inverse Opal Film as a Photoanode for Photoelectrochemical Solar Energy Conversion under Visible-Light Irradiation

This work focuses on the crystal size dependence of photoactive materials and light absorption enhancement of the addition of carbon dots (CDs). mac-FTO (macroporous fluorine-doped tin oxide) films with an inverse opal structure are exploited to supply enhanced load sites and to induce morphology control for the embedded photoactive materials. The Bi2WO6@mac-FTO photoelectrode is prepared directly inside a mac-FTO film using a simple in situ synthesis method, and the application of CDs to the Bi2WO6@mac-FTO is achieved through an impregnation assembly for the manipulation of light absorption. The surface morphology, chemical composition, light absorption characteristics and photocurrent density of the photoelectrode are analyzed in detail by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), UV-vis diffuse reflectance spectra (DRS), Energy dispersive X-ray analysis (EDX) and linear sweep voltammetry (LSV).