Ni@NiO Core–Shell Structure-Modified Nitrogen-Doped InTaO4 for Solar-Driven Highly Efficient CO2 Reduction to Methanol

This investigation demonstrates the photocatalytic properties and activities of N-doped InTaO4 photocatalysts, which were prepared by impregnating Ni and the use of a modified Ni@NiO core–shell nanostructure-cocatalytic method for the reduction of CO2 to methanol. X-ray absorption spectroscopy (XAS) clearly indicates the oxygen vacancies and mechanism of a series of InTaO4-based photocatalysts. Nitrogen doping produces visible-light-responsive photocatalytic activity and further enhances absorbance. The cocatalytic method not only dramatically enhances absorbance, but also efficiently avoids electron–hole recombination that would otherwise be caused by electrons and holes separated from the crystal. The photocatalytic activity that was determined by the methanol yield demonstrates that N-doped samples give approximately twice the yield of undoped ones, whereas the cocatalytic method gives about triple the yield. A mechanism is aided in attempts to elucidate the correlation between structures and activities.