Morphological optimization of CeO2 via low-temperature hydrothermal synthesis for enhanced photocatalytic performance in NO oxidation and CO2 conversion

Photocatalysis has proven to be a green technology that possesses the synergy between addressing climate change and combating air pollution. Compared with traditional photocatalysts, Cerium oxide (CeO2) holds distinct advantages such as low-cost, and high affinity for Ce3+/Ce4+ redox pair. This study presents a systematic investigation into the modification of CeO2 morphologies via optimized one-step hydrothermal synthesis method with low-temperature control. The findings reveal that CeO2 nanorods exhibited the notable photocatalytic performance, achieving 71.8% NO degradation while generating a mere 4.1% of toxic byproducts. Additionally, the promising CO and CH4 yields from CO2 conversion were 4.11 and 3.67 µmol g–1 h–1, respectively. The improvement in photocatalytic activity is attributed to the relationship between the specific surface area and the defects within the CeO2 nanorods structure. Furthermore, CeO2 nanorods also emerged as promising candidates for superior and sustainable photocatalytic CO2 conversion, demonstrating high stability, with only 0.7% and 1.1% reduction in CO and CH4 yields after four successive photocatalytic cycles. This study underscores the potential of CeO2 nanorods in advancing green technologies for clean energy and contributes valuable insights to the field of practical zero emissions strategies.