以钨酸钠与硝酸银为原料，采用水热法将Ag元素引入斜方晶型WO₃光催化剂，探究了Ag元素提高WO₃光催化活性的机理。光催化降解实验结果表明，当n（Ag）：n（W）=1：500时，甲苯的降解效率达到90%以上，与未掺杂Ag的WO₃相比，其降解效率提高11.7%；第3次循环时甲苯降解率达到82%，表明Ag/WO₃具有较高的稳定性。综合表征结果表明，Ag元素的添加不改变WO₃的晶型结构，随着Ag元素掺杂比例的增加，WO₃粒径不断减小，禁带宽度由2.23 eV降低为1.72 eV。Ag元素的掺杂增加了WO₃中的氧空位，促进了电子-空穴的分离。但当n（Ag）：n（W）>1：500时，过多的氧空位形成了新的复合中心，更多的电子被束缚，导致WO₃催化活性降低。

Silver is doped into orthorhombic tungsten trioxide (WO₃) through hydrothermal method with sodium tungstate and silver nitrate as raw materials.Influence of silver doping on the photocatalytic activity of Ag/WO₃ is investigated.The as-prepared catalysts are characterized to explain the amelioration effect of silver on WO₃ in detail.Photocatalytic degradation experiment results show the degradation rate of toluene over Ag/WO₃ exceeds 90% when n(Ag):n(W)=1:500,which is 11.7% higher than that over WO₃ without Ag doping.The degradation rate of toluene can reach 82% when Ag/WO₃ is used for the third recycling,indicating a high stability.Comprehensive analysis results show that the addition of silver has not impact on the crystal structure of WO₃.The particle size of WO₃ decreases with the increase of Ag doping ratio.Silver doping reduces bandgap energy of WO₃ from 2.23 eV to 1.72 eV,enhances oxygen vacancies in WO₃ and promotes separation of electron and hole.However,excessive oxygen vacancies form new recombination centers and affect the separation process of electron-hole negatively when n(Ag):n(W) exceeds 1:500,thus the degradation rate of toluene decreases.

李阳达(1993-),男,硕士研究生,研究方向为环境功能材料,liyangda50@163.com