N

Cdcodoped TiO

2

was synthesized by thermolysis method. The products were characterized by X-ray diffraction (XRD)

X-ray photoelectron spectroscopy (XPS) and UVvisible diffuse reflectance spectra (DRS) analyses

respectively. The photocatalytic activities of samples were studied on the degradation of methyl orange (MO). The results showed that photacatalysts possessed an anatase crystalline framework with particle sizes of 10~15 nm. N atom was incorporated into the TiO

2

crystal lattice

while Cd atoms existed on the crystal surface. Doping resulted in the observation of optical absorption edges shifting to the red light. It indicated a strong NCd synergistic interaction appeared to play a decisive role in driving the excellent photoactivity performance of N

Cdcodoped TiO

2

. Firstprinciples density functional theory (DFT) calculations were performed to explore the effect of dopants on electronic and optical properties of N

Cd TiO

2

. There were impurities states between the valence band and the conduction band

which came from N2p and Cd5s

respectively. The electron on the valence band could transit to the impurity states

and then were migrated secondly to the conduction band in the light irradiation. So the electronic excitation in N

CdTiO

2

became easier compared to pure TiO

2

and the absorption edge shifted to the visible light region. It could account for the experimentally observed optical absorption edge of N

CdTiO

2

shifting toward the lower energies.