可见光活性Ag/g-C3N4复合光催化剂的光还原制备及其光催化性能研究

以硝酸银与三聚氰胺为原料，采用简单的热解和光还原法制备出纳米银负载的复合可见光催化剂Ag/g-C₃N₄，并通过XRD、TEM、EDX、FT-IR、UV-vis、PL、XPS对样品进行表征，结果表明在所制备的Ag/g-C₃N₄复合光催化剂中纳米Ag粒径为5~15 nm，在g-C₃N₄载体上均匀分散。对不同质量分数的Ag/g-C₃N₄复合光催化剂的光催化评价结果表明：当Ag/g-C₃N₄的质量分数为25%时，样品25-PACN有较强的光吸收以及较低的电子空穴复合率而表现出最高的光催化活性，对罗丹明B的降解率达75%；5次循环实验后，25-PACN的活性仍在60%左右，稳定性较好。

Preparation and photocatalytic activity of Ag/g-C3N4 composite photocatalysts for use under visible light

In this paper, a series of Ag/g-C₃N₄ composite photocatalysts were prepared by a simple pyrolysis and photoreduction method using melamine and silver nitrate as raw materials. The structures of the composite photocatalysts were characterized by XRD, UV-vis, TEM, EDX-mapping, XPS, FT-IR and PL techniques. The results indicate that Ag nanoparticles with diameters of 5 to 15 nm were homogeneously loaded onto g-C₃N₄ supports. The photocatalytic activities of the composite photocatalysts with different mass fractions show that when the mass fraction of Ag/g-C₃N₄ is 25%, the resulting 25-PACN sample has the highest photocatalytic activity for RhB degradation, stronger light absorption and the lower electron-hole recombination rate. The photocatalytic degradation ratio of the 25-PACN sample is 75% in the first cycle and about 60% after 5 cycles which shows its excellent stability.