Tailoring Cadmium Composition on Titanium Dioxide To Achieve Enhanced Photocatalytic Glucose Fuel Cell Anode Performance

Abstract

In this study, titanium dioxide (TiO2)-supported Cd catalysts were prepared at 0.05-3% of Cd loading by employing the incipient wetness impregnation method. These catalysts were characterized via X-ray diffraction (XRD), scanning electron microscopy-energy-dispersive X-ray (SEM-EDX), high-angle annular dark-field scanning transmission electron microscopy and TEM-EDS mapping, inductively coupled plasma-mass spectrometry ( ICP-MS), X-ray photoelectron spectroscopy (XPS), temperature-programmed reduction (TPR), temperature-programmed oxidation (TPO), and temperature-programmed desorption (TPD). XRD and TEM analysis showed that TiO2 exhibited an anatase structure. SEM-EDX and mapping, XPS, TPR, TPO, and TPD analysis revealed that the Cd addition to TiO2 altered the electronic structure and surface properties of TiO2. Photocatalytic electro-oxidation measurements were conducted to define the glucose electro-oxidation activity, stability, and resistance of catalysts with cyclic voltammetry, chronoamperometry (CA), and electrochemical impedance spectroscopy (EIS) in 1 M KOH + 0.5 M glucose solution at 100 mV/s in the dark and under UV illumination. 0.1% Cd/TiO2 catalyst showed the best photocatalytic glucose electro-oxidation activity with a 6 mA/cm(2) specific activity compared to the dark (0.89 mA/cm(2)). CA and EIS measurements indicated that 0.1% Cd/TiO2 catalyst exhibited the highest stability and the lowest resistance. In conclusion, Cd-doped TiO2 is a promising catalyst for photocatalytic fuel cells.