氧掺杂高比表面积g-C3N4的制备及其光催化性能研究

Preparation of oxygen-doped porous g-C3N4 and efficient photocatalytic activity

以二氰二胺(C2H4N4)为原料采用模板剂法制备了高比表面积的石墨相氮化碳(p-C3N4),并通过热聚合的方式将氧掺杂于p-C3N4中制备了氧掺杂高比表面积石墨相氮化碳(O-p-C3N4)。通过X射线衍射光谱(XRD)、傅里叶红外光谱(FT-IR)、氮气吸附-脱附(BET)、紫可见漫反射光谱(UV-Vis)、荧光光谱(PL)对催化剂进行表征。在500 W氙灯照射下通过光催化降解罗丹明B和光催化水解制氢2种方式对催化活性进行考察。结果表明:氧掺杂能够有效地降低光生-电子空穴的复合几率,提高光催化活性。其中80%O-p-C3N4表现出最佳活性,降解罗丹明B的速率和产氢速率分别是p-C3N4的3.8倍、2.9倍,且循环使用5次后依然具有很高的催化活性。

Porous graphite carbon nitride(p-C3N4)was prepared by thermal polymerization using dicyandiamide(C2H4N4)as raw materials,and then oxidatively treated with hydrogen peroxide to prepare oxygen-doped g-C 3 N 4 catalyst(O-p-C3N4).The structures of samples were characterized by XRD,FT-IR,BET,UV-Vis,and PL.The photocatalytic activity and stability of samples was evaluated by the degradation ofrhodamine B(RhB)and hydrogen conversion by water splitting under xenon lamp of 500 W with light filters.The result indicates that the oxygen-doped increases the electron/hole separation rate,narrows the band gap energy and increases photocatalytic activity.The catalyst 80%O-p-C3N4 shows the highest photocatalytic activity,which is almost 3.8 and 2.9 times than p-C3N4 for degradation of rhodamine B(RhB)and hydrogen conversion by water splitting,and the catalytic activity is almost unchanged after five times used.