ZnS/TiO_(2)催化剂光催化CO_(2)的还原性能

The Study on photocatalytic CO_(2)reduction performance of ZnS/TiO_(2)

利用光催化技术将CO_(2)转化为有用化学品或太阳能燃料是解决能源和环境问题的有效方法之一.通过水热法制备了ZnTi-LDH,并通过0.1 mol·L^(−1)Na_(2)S溶液对其进行硫化处理,制备了不同硫化时间的ZnS/TiO_(2)光催化剂.采用XRD、TEM、UV-vis DRS、化学工作站等方法,详细分析了硫化时间对光催化剂的组成、结构、光吸收性能和电化学质以及光催化H2O还原CO_(2)性能的影响.与ZnTi-LDH相比,硫化处理得到的ZnS/TiO_(2)光催化CO_(2)还原性能均有明显提高,其中ZnS/TiO_(2)/S-1 h的样品具有最高的光催化活性,其CO和H_(2)的产率分别为25.35μmol·(g·h)^(−1)和15.54μmol·(g·h)^(−1),是未硫化样品的4倍和1.5倍.硫化后样品光催化性能的改善可归因于,硫化样品较好的可见光吸收性能、较高的电子空穴分离效率以及其光电子还原能力的提高.

Converting CO_(2)to chemicals and solar fuels is an effective way to solve the energy shortage and environmental problems.In this work,ZnTi-LDH was prepared by hydrothermal method and sulfidized with different time by using 0.1 mol·L^(−1) Na_(2)S solution,which was tested in photocatalytic CO_(2)reduction.The XRD,TEM,UV-vis DRS and chemical station were employed to investigate the effects of sulfidation time on the composition,structure,light absorption,electrochemical properties and photocatalytic activity for CO_(2)reduction.Compared with ZnTi-LDH,the photocatalytic CO_(2)reduction performance of ZnS/TiO_(2)obtained by the sulfidation treatment was significantly improved,and ZnS/TiO_(2)/S-1h exhibited the highest photocatalytic activity with CO and H_(2)production rates of 25.35μmol·(g·h)^(−1)and 15.54μmol·(g·h)^(−1),respectively,which were 4 and 1.5 time higher than those of ZnTi-LDH.The enhancement of photocatalytic activity for sulfidized ZnTi-LDH was attributed to the better absorption capacity for visible light,the higher separation efficiency of photogenerated electrons an holes and the increase of reduction ability of photogenerated electrons.