Efficient Photoreduction of Diluted CO2to Tunable Syngas by Ni−Co Dual Sites through d‐band Center Manipulation

Abstract

AbstractPhotocatalytic conversion of CO2into syngas is a promising way to address the energy and environmental challenges. Here we report the integration of Ni−Co dual sites on Ni doped Co3O4ultrathin nanosheets assembled double‐hollow nanotube (Ni−Co3O4NSDHN) for efficient photoreduction of low‐concentration CO2.Quasiin situ spectra and density functional theory calculations demonstrate that the declining ofd‐band center of Ni−Co dual sites enables the electrons accumulation in thedxz/dyz‐2π* anddz2‐5σorbitals. As a result, the binding strength of *CO is weakened and the *H adsorption site is modulated from metal sites to an oxygen site. Remarkably, Ni−Co3O4NSDHN exhibits superior diluted CO2photoconversion activity and controllable selectivity under the irradiation of visible light or even natural sunlight. A syngas evolution rate of 170.0 mmol g−1 h−1with an apparent quantum yield of 3.7 % and continuously adjustable CO/H2ratios from 1 : 10 to 10 : 1 are achieved.