Ni-phyllosilicate nanotubes coated by CeO2 for ultra-efficiency of 36.9% and near-limit CO2 conversion in solar-driven conversion of CO2-to-fuel

Solar-driven CO2 reduction by methane (CRM) into valuable syngas not only mitigates greenhouse gases but also provides high-value syngas. However, it is still a daunting challenge to achieve high solar-to-fuel efficiency and good durability simultaneously. Here, a novel strategy of direct photothermocatalytic CO2 is proposed based on a unique nanocomposite of ceria coated Ni-phyllosilicate nanotubes (Ni-psnts@CeO2). A record-high solar-to-fuel efficiency (36.9 %) with very high production rates of H2 and CO (120.90 and 136.84 mmol gcat min−1) and high CO2 conversion rate (90.4 %) close to thermodynamic limit are demonstrated. Excellent long-term durability is achieved due to its extremely low carbon deposition rate of 1.3 × 10−4 gc gcat h−1 under focused UV–vis-IR irradiation for 100 h. These high performances are partially attributed to the active involving of lattice oxygen and oxygen vacancies from ceria in carbon gasification and CO2 activation, which are confirmed by 18O isotope labeling and In-situ DRIFTS measurements. In addition, decreased activation energy enabled via photoactivation effects from photoexcited hot electrons also benefits high activities under direct light illumination. This work offers novel approaches for highly efficient and stable solar-driven CO2-to-fuel conversion.