Carbon-doped nickel oxide hollow nanospheres for enhanced photocatalytic CO₂ reduction

Through artificial photosynthesis the conversion of CO2 assisted by photocatalyst is conducive to alleviating greenhouse effect and energy shortage. Herein, the carbon-doped NiO hollow nanospheres (C-NiO) were constructed by using the glucose-based carbon spheres as sacrificial template and dopants of carbon. The obtained C-NiO samples with adjustable carbon content show high specific surface area (114.02-139.49 m(2)g(-1)) as compared with NiO (13.93 m(2)g(-1)), which is beneficial to the adsorption and activation of more CO2 molecules, thereby improving CO2 photo-reduction. As expected, the C-NiO samples convert CO2 into CO and CH4 with high yield efficiency and stability due to the hollow nanostructure and the carbon-doping, which could increase CO2 adsorption and light utilization, gain more active sites, reduce band gap and propel the charge separation and migration. The optimization of morphology and composition of photocatalysts is an effective strategy for the enhancement of CO2 photo-reduction, suggesting the great application prospect of the carbon-doped NiO hollow nanospheres in photocatalysis.