A unique Prussian blue analog-derived three-dimensional (3D) hollow Ni-Co bimetal oxide compound supported on two-dimensional (2D) g-C3N4 nanosheets was successfully prepared using a low-temperature annealing method. A spatial conductive frame was formed owing to formation of a p-n heterojunction between the Ni-Co bimetallic oxide and g-C3N4, which accelerated photogenerated carrier migration and inhibited recombination. The hollow Ni-Co bimetallic oxide had pores that allowed facile gas circulation. After g-C3N4 recombination, the synergistic effect of the two catalysts degraded NO (600 ppb) under visible light with an extremely high conversion rate of up to 59.1%. Cycling experiments and X-ray diffraction results confirmed the stability of the composite catalyst, which has broad application prospects in environmental science.