中文摘要：

分别采用水热法（AgxS-H）和原位离子交换法（AgxS-IE）制备了AgxS.采用扫描电镜（SEM）、X射线衍射光谱、紫外可见近红外吸收光谱、N2吸附-脱附、X射线光电子能谱和表面光电压测试对催化剂进行了表征.以光（λ≥420 nm）降解亚甲基蓝为模型反应,考察了AgxS的光催化性能.与AgxS-IE相比,AgxS-H具有较小的粒径、较大的禁带宽度、较低光生电荷复合率,因此具有较高的光催化活性.此外,AgxS-H还表现了较好的稳定性,循环使用五次仍能够保持较高的光催化活性.结果表明,AgxS光催化降解亚甲基蓝主要以羟基自由基氧化为主,光生空穴氧化为辅的光催化氧化过程.AgxS-H作为一种有效的光催化剂,在降解有机染料污水方面具有潜在的应用价值.

英文摘要：

AgxS crystals were synthesized via hydrothermal（AgxS-H） and in situ ion-exchange（AgxS -IE） meth-ods. The samples were characterized by scanning electron microscopy, X-ray diffraction, ultravio-let-visible-near infrared absorption spectroscopy, N2 adsorption-desorption, X-ray photoelectron spectroscopy and surface photovoltage measurements. The photocatalytic performance was inves-tigated for the decomposition of methyl blue（MB） under visible light irradiation（λ ≥ 420 nm）. The AgxS -H had smaller particles, wider band gap and weaker recombination of photoinduced charges than AgxS -IE, resulting in a higher photocatalytic activity. Moreover, AgxS -H was stable, and could be reused five times without loss of photocatalytic activity. Additionally, a possible pathway for the photocatalytic degradation of MB over AgxS has been proposed, that MB was oxidized mainly by hydroxyl radicals and partly via electron holes generated in the AgxS. AgxS -H is an efficient photo-catalyst and has great potential for the degradation of harmful organic dyes in wastewater.