Photocatalysts with a "memory" effect can regain their activity after light is removed. We developed a novel NiMoO4/Bi2O2CO3 hybrid photocatalyst through a simple hydrothermal process. This memory effect results from the trapping and release of photogenerated electrons, facilitated by the NiMoO4/Bi2O2CO3 hybrid's compatible band structures and internal electrostatic field, which enhance electron transfer. This photocatalyst effectively removes Rhodamine B (RhB), with a 34 % increase in oxidation after sunlight exposure. The optimized NiMoO4/Bi2O2CO3 composite achieves 84 % photocatalytic degradation of RhB (kapp = 0.0196 min−1) under visible light in 90 min, proving effective for water pollutant removal both during and after light exposure.