Constructing oxygen absorption and activation sites in Ce-doped g-C3N4 photocatalyst for effective removal of amoxicillin: Performance, mechanism and degradation pathways

•The photocatalytic efficiency of Ce/g-C3N4−x for decomposing of amoxicillin was enhanced more than 3 times.•The doped Ce and N vacancies synergistically accelerate the electron transfer and reduce the photocarriers recombination.•The improvement of O2− is attributed to the enhanced oxygen absorption and activation performance of Ce doping.•The pathway of photocatalytic degradation of amoxicillin is proposed based on HPLC-MS and theoretical calculations.