An enhanced oxygen evolution reaction (OER) was realized via photoelectrochemical measurements of metal-organic frameworks (MOFs)-derived metal oxides doped with carbon dots (CDs). High-quality nanorod-shaped porous composites (with average width of 55 nm and average length of 490 nm) of trimetallic MOFs/CDs were obtained through solvothermal method, followed by calcination at 300 °C. Upon calcination, X-ray diffraction pattern of MOF converted into diffraction signals of cubic-phase CeO2 and ZnCo2O4. The formation of multi-metal oxides with various valence states was further verified via X-ray photoelectron spectroscopy (XPS) measurement. Simultaneous presence of CDs and metal-oxides created a synergistic effect to enhance light absorption and align band-edge positions to facilitate charge transfer. Photoelectrochemical performance of the calcined trimetallic MOF/CDs confirmed excellent OER activity with small overpotential value of 149 mV vs. RHE. Results showed long-term stability with superior OER activity over 10 h of continuous performance, which nominates prepared composite as next-generation photoactive materials.
