Ag负载ZnS光催化剂的制备与光催化制氢

Preparation of Ag-doped ZnS photo catalyst and photocalytic property for H2 production

摘要:

为实现光催化制氢,通过模板剂水热合成和浸渍还原法制备出Ag负载ZnS光催化剂．利用XRD、SEM和UV-vis对样品进行结构和光学性质表征,利用光催化分解Na₂S+Na₂SO₃溶液制氢评价光催化性能．结果表明:在酸性条件下,模板剂质量浓度较低而硫源和锌源较多时,样品为棒状,主要以立方闪锌矿结构存在;反之,样品主要为球状,以纤维锌矿结构和闪锌矿结构共存．碱性条件下,样品成球状,以立方闪锌矿结构存在．EDS分析表明,少量的Ag负载到ZnS样品表面．实验中制备的样品A为混晶结构,其对应的吸收光谱红移最大,同时负载Ag有利于光生电子和空穴的分离,表现出最佳的光催化制氢性能．

Abstract:

To fulfill photocatalytic hydrogen production, Ag-doped ZnS photo catalyst was prepared by template hydrothermal method and solution infiltration and reduction method. The structure and optical property were studied by XRD, SEM and UV-vis, respectively. The photocatalytic activity of the catalysts was evaluated by splitting Na₂S+Na₂SO₃ solution into H₂. The results show that in acid bath with a small amount of template and a large amount of Thiourea and Zn(Ac)₂, the sample is of rod structure and exists mainly in the form of sphalerite; whereas the sample is of ball structure and co-exists in the form of wurtzite and sphalerite. In a base bath, ZnS is of rod structure and exists mainly in the form of sphalerite. EDS analysis indicates that a small amount of Ag is loaded on the ZnS. The sample A has mixed-crystallized structure with bigger red-shifted in UV-vis absorption spectrum, and the doped Ag is liable to separate the photo-induced e-and h+, which presents the best photocatalytic activity for H₂ production.