Photocatalytic synthesized low content CeO2-modified rutile heterojunction photocatalysts with enhanced wastewater treatment and H2 evolution performances

• A novel CeO2/rutile composite with only 1.28 wt% CeO2 was synthesized via a simple photocatalytic method, achieving 95.83% MB degradation, 72.84% TC degradation, and 87.57 μmol/g H2 evolution. • DFT calculations revealed that light irradiation and oxygen vacancies on rutile (110) facet promote Ce3+ adsorption, facilitating the formation of a type-II heterojunction. • The type-II heterojunction enhances charge separation and generation of reactive species (·OH, ·O2−) and H2, significantly boosting photocatalytic performance. • This work provides a novel strategy for preparing low-content heterojunction photocatalysts with high efficiency for wastewater treatment and clean energy production.