常见离子对玉米秸秆为牺牲剂的光催化制氢影响

Effect of ions on photocatalytic H_(2) production using corn straw as sacrificial agent

以玉米秸秆为牺牲剂、Pt/TiO_(2)为催化剂,研究玉米秸秆不同部位、不同组分以及液相环境的pH、常见阴阳离子的加入对光催化制氢的影响。利用XRD、TGA和UV-vis DRS表征玉米秸秆的组分和光吸收特性。结果表明,在pH=5~7时制氢量适中、pH<5和pH=8~10时制氢受到抑制、pH>10时制氢得到提升;强酸阴离子、强碱金属离子对该体系制氢无影响;CO_(3)^(2-)和HPO_(4)^(-)对制氢有不同程度的促进作用;Fe^(3+)、Cu^(2+)和Zn^(2+)因其氧化性强弱顺序和弱电离性对制氢有不同程度的抑制作用。综合上述实验结果分析了不同离子对制氢影响规律和作用机理。

In this study,corn straw and Pt/TiO_(2) were used as sacrificial agent and catalyst,respectively.The effects of different parts and components of corn straw,pH and the addition of common cation and anion of liquid environment on photocatalytic hydrogen production were studied.X-Ray diffraction(XRD),thermogravimetric analysis(TGA)and UV-vis diffuse reflectance spectra(UV-vis DRS)were used to characterize the components and light absorption characteristics of corn straw.The results show that the hydrogen production was moderate in the range of pH=5—7,inhibited in the range of pH<5 and pH=8—10,and increased in the range of pH>10.Strong acid anions and alkali metal ions have no effect on hydrogen production.CO_(3)^(2-) and HPO_(4)^(-) promoted hydrogen production in different degrees.Fe^(3+),Cu^(2+) and Zn^(2+) have different degrees of inhibition on hydrogen production due to their strong or weak order of oxidation and weak ionization.Based on the above experimental results,the law and mechanism of the influence of different ions on hydrogen production are analyzed.