NiO@Ni nanoparticles embedded in N-doped carbon for efficient photothermal CO2 methanation coupled with H2O splitting
Yun Zhou, Peng Zheng, Fang Wang, Fangna Gu, Wenqing Xu, Qinyang Lu, Tingyu Zhu, Ziyi Zhong, Guangwen Xu, Fabing Su
Abstract
Photothermal carbon dioxide (CO2) methanation has attracted increasing interest in solar fuel synthesis, which employs the advantages of photocatalytic H2O splitting as a hydrogen source and photothermal catalytic CO2 reduction. This work prepared three-dimensional (3D) honeycomb N-doped carbon (NC) loaded with core–shell NiO@Ni nanoparticles generated in situ at 500 °C (NiO@Ni/NC-500). Under the photothermal catalysis (200 °C, 1.5 W/cm2), the CH4 evolution rate of NiO@Ni/NC-500 reached 5.5 mmol/(g·h), which is much higher than that of the photocatalysis (0.8 mmol/(g·h)) and the thermal catalysis (3.7 mmol/(g·h)). It is found that the generated localized surface plasmon resonance enhances the injection of hot electrons from Ni to NiO, while thermal heating accelerates the thermal motion of radicals, thus generating a strong photo-thermal synergistic effect on the reaction. The CO2 reduction to CH4 follows the *OCH pathway. This work demonstrates the synergistic effect of NiO@Ni and NC can enhance the catalytic performance of photothermal CO2 reduction reaction coupled with water splitting reaction.