采用高温煅烧法成功制备了块状g-C₃N₄和g-C₃N₄纳米材料，利用XRD、SEM、FT-IR、UV-Vis、PL等方法对材料进行表征，并研究其降解头孢曲松钠的光催化活性和机理。当降解时间为120 min、头孢曲松钠质量浓度为10 mg/mL、半导体材料的加入量为0.1 g时，块状g-C₃N₄和g-C₃N₄纳米材料的降解率分别为67.74%和85.84%，g-C₃N₄纳米材料的光催化活性高于块状g-C₃N₄；对催化机制研究发现，空穴（h⁺）和羟基自由基（·OH）起主要催化作用，超氧自由基（·O^-₂）次之。对g-C₃N₄纳米材料的稳定性进行评价，3次循环催化后材料稳定性良好。

The overuse and misuse of ceftriaxone sodium is a serious issue threating human and ecological health.It is urgent to explore an effective way to eliminate antibiotic residues from the aquatic environment.Bulk g-C₃N₄ and nanoscale g-C₃N₄ photocatalytic materials are prepared successfully via high temperature calcination method,and both are characterized by XRD,SEM,FT-IR,UV-Vis and PL,etc.Photocatalytic degradation of ceftriaxone sodium over the as-prepared g-C₃N₄ materials under visible light irradiation is carried out to evaluate the catalytic activity and investigate the catalytic mechanism.The results indicate that the degradation rates over bulk g-C₃N₄ and g-C₃N₄ nanosheets are 67.74% and 85.84%,respectively when the degradation under visible light irradiation lasts for 120 min,the mass fraction of ceftriaxone sodium is 10 mg·mL^-1 and the dosage amount of semi-conductive materials is 0.1 g.The g-C₃N₄ nanosheets shows much higher photocatalytic activity than bulk g-C₃N₄.It is found through exploring the catalytic mechanism that h⁺ and ·OH play major roles in catalytic actions,·O^-₂ comes next.Moreover,the as-prepared g-C₃N₄ nanosheets samples are of high stability after three times of uses.