Cu/Sr_3Ti_2O_7的制备及其光催化分解水制氢活性

Preparation of Cu/Sr_3Ti_2O_7 and Its Photocatalytic Activity of Water-splitting for Hydrogen Evolution

采用聚合合成法(PCM)合成出层状钙钛矿结构的Sr_3Ti_2O_7,进而负载Cu离子,制成Cu/Sr_3Ti_2O_7催化剂.以超纯水和甲醇牺牲剂体系的光催化分解反应为探针,通过检测氢气生成速率评价了催化剂的光催化性能,并借助光电子能谱(XPS)、X射线衍射(XRD)分析、紫外-可见漫反射光谱(UV-VisDRS)等手段对催化剂进行了表征.实验结果表明,Cu在催化剂中以多价态存在,Cu+和吸附氧有利于光生电子的转移.Cu/Sr_3Ti_2O_7催化剂较之纯Sr_3Ti_2O_7催化剂活性大大提高,Cu最佳负载量为1.5%(w).产氢速率可稳定在550-600μmol·h^(-1).还原过的Cu/Sr_3Ti_2O_7催化剂产氢速率最高可达1140.8μmol·h^(-1).

Sr3Ti2O7 photocatalyst with perovskite-layered structure was synthesized by polymerized complex method （PCM）. Cu ion as an effective dopant was loaded onto Sr3Ti2O7 catalyst. Cu/Sr3Ti2O7 catalyst was applied in the mixture of water and methanol, methanol was used as a sacrificial agent under ultra-violet irradiation, and the catalyst was characterized by XPS, XRD, and UV-Vis DRS. The results showed that Cu existed in several kinds of valence and the photocatalytic activity of Cu/Sr3Ti2O7 was superior to that of pure Sr3Ti2O7. Cu^＋ and adsorbed oxygen can accelerate the interfacial electron transfer. When the amount of Cu was 1.5%（w）, the best catalytic effect was obtained and the stable average hydrogen evolution rate was about 550-600 μmol ·h^-1. The Cu/SraTi2O7 after reduction attained the highest hydrogen evolution rate that was close to 1140.8 μmol·h^-1.