偏硼酸锶/碳酸锶复合催化剂光催化还原CO2生成CH4的研究

采用溶胶-凝胶法制备出SrB₂O₄和SrCO₃复合催化剂(SrB₂O₄/SrCO₃). 紫外光催化还原CO₂生成CH₄的实验证明, SrB₂O₄/SrCO₃复合催化剂的光催化活性已超过SrB₂O₄和TiO₂(P25)催化剂. 利用X 射线电子衍射(XRD)谱、透射电子显微镜(TEM)和等温氮气吸附-脱附分析确定了催化剂的晶相结构、粒子尺寸和比表面积.利用紫外-可见(UV-Vis)漫反射吸收光谱、X射线光电子能谱(XPS)的价带谱和荧光光谱(PL)确定了催化剂的能带结构, 结果表明: SrB₂O₄/SrCO₃复合催化剂异质结构有利于光生载流子的分离, 从而抑制了光生电子和光生空穴的复合, 提高了光生电子和光生空穴在固液界面参加光催化反应的利用率. 因此, SrB₂O₄/SrCO₃复合催化剂的紫外光催化活性得到了有效的提高.

Investigation on Photocatalytic Reduction of CO2 into CH4 Using SrB2O4/SrCO3 Composite Catalyst

An SrB₂O₄/SrCO₃composite catalyst is synthesized by the simple sol-gel method. Reduction of carbon dioxide into methane in the presence of water is used to evaluate the photocatalytic activity of the composite catalyst. SrB₂O₄/SrCO₃exhibits better photocatalytic performance than TiO₂(P25) and SrB₂O₄ under irradiation with UV light. The crystalline structure, crystallite size, and the BET surface areas of the resultant photocatalysts are studied via the techniques of X-ray diffraction (XRD), transmission electron microscopy (TEM), and nitrogen adsorption-desorption isotherms. The energy levels of the SrB₂O₄/SrCO₃ photocatalyst are determined from characterization with UV-Vis diffuse reflectance absorption spectra, X-ray photoelectron spectroscopy (XPS), and photoluminescence (PL) measurements. The heterojunction formed at the SrB₂O₄/SrCO₃interface efficiently promotes photogenerated carrier separation and increases the use of photogenerated carriers in photocatalytic reactions at the solid/liquid interface, resulting in high photocatalytic activity under UV light.