Lewis acid activated CO2 reduction over a Ni modified Ni–Ge hydroxide driven by visible-infrared light

Abstract

Improvement of light harvesting and reaction kinetics is of great importance for achieving efficient solar-driven CO₂ reduction. Here, a Ni modified low-crystalline Ni–Ge containing hydroxide with Lewis acid sites was synthesized in highly reductive NaBH₄ solution and exhibited 9.3 μmol g_cat.⁻¹ h⁻¹ CO and 3.5 μmol g_cat.⁻¹ h⁻¹ CH₄ generation rates under visible light irradiation, and even achieved a 3.8 μmol g_cat.⁻¹ h⁻¹ CO evolution under infrared light irradiation. The wide-spectrum light harvesting resulted from the light absorption from the localized surface plasmonic resonance of Ni nanoparticles. In addition, the Lewis acid can activate CO bonds to decrease the kinetic barriers of CO₂ reduction. The design concept that rationally combines the advantages of expanding the spectral response and activating CO₂ may offer a new strategy for efficient solar energy utilization.