Efficient nitrogen oxides (NO_x) removal from the urban atmosphere is still a target for the researchers. Herein, a Zn₂Al-CO₃ based layered double hydroxide (LDH) was doped with increasing amounts of Eu³⁺ (0.01–0.04) and the photocatalytic oxidation of NO_x gases was investigated. The LDHs were synthesized by a facile coprecipitation method at room temperature and ambient pressure. The successful Eu³⁺ substitution in the LDH layers induces a shift in the M−O bonds that modifies the electronic band structure of the doped photocatalysts. Compared to the undoped LDH, the NO_x removal efficiency was enhanced by ∼ 17–25 % under UV–Vis light irradiation. Remarkably, a NO_x removal efficiency of ∼ 47 % was attained by the optimally doped LDH under Visible irradiation (420 nm), surpassing raw LDH (∼ 9 %). Moreover, the Eu³⁺ doped LDHs retained its photocatalytic efficiency during long periods of irradiation during consecutive tests with high selectivity (>90 %). Photoluminescence studies indicated that Eu³⁺ was located in a non-centrosymmetric position, thereby producing structural disorder within the lattice. Eu doping promoted charge separation and a higher production of ⋅OH radicals as verified by time-resolved photoluminescence and electron paramagnetic resonance, respectively. We believe this work reports unprecedent results obtained by Eu-doping of Zn₂Al-based LDHs under visible light for NO_x photooxidation and serves as a new strategy to prepare functional LDHs for other photocatalytic applications.