Photothermal Coupling Effect Enhances CO2 Conversion to Solar Fuels over Ni/CeZrO2 Catalyst

Abstract

Zirconium dioxide (ZrO₂) has been applied to convert CO₂ into valuable chemicals, thereby contributing to energy harvesting in a sustainable manner. However, the large bandgap of ZrO₂ has bottlenecked its photocatalytic water splitting efficiency, hindering its application in advancing more economic CO₂ and H₂O conversion. Here, a cerium–zirconium solid solution (CeZrO₂) with Ni loading is synthesized and its strengths in catalyzing photothermal redox reaction with CO₂ and H₂O is demonstrated. The experimental findings demonstrate that the CO yield of the Ni/CeZrO₂ catalyst is remarkably augmented to 673.5 μmol g⁻¹ h⁻¹ under concentrated light radiation (4.0 W cm⁻²), which is a substantial increase of 70.6-fold in CO yield and 69.73-fold in energy conversion efficiency when compared to the 9.4 μmol g⁻¹ h⁻¹ yield observed under standard irradiation conditions (0.4 W cm⁻²). This success to the decrease in bandgap with the incorporation of Ce and the synergized catalytic mechanism is attributed. Specifically, these sites achieve rational accommodation of reactants and accelerate the reaction kinetic. This work sheds light on the modification strategy for broad bandgap catalysis for efficient photothermal energy conversion.