球磨法制备Bi12GeO20/WO3复合材料及可见光催化去除NO性能研究

采用简易球磨法制备了一系列Bi₁₂GeO₂₀/WO₃二元半导体复合材料，并对其物相、光学和电化学性质进行了分析。可见光光催化去除NO试验表明：随着WO₃负载量的逐渐增大，材料去除活性先增大后减小，这主要归结于合适的相组成以及异质结提高了界面载流子的分离效率。另外，WO₃的加入可有效抑制有毒中间产物NO₂的生成，从而促进硝酸根与亚硝酸根的生成。通过活性物种捕捉试验发现，超氧自由基和空穴在光催化反应中均起到了主要作用，羟基自由基起到了辅助作用。能带结构分析表明，复合材料的光催化机制遵从Ⅰ型过程。循环试验证明，材料具有较好的重复利用性和结构稳定性。

Study on fabrication of Bi12GeO20/WO3 composites by ball milling and visible-light photocatalytic NO removal

A series of Bi₁₂GeO₂₀/WO₃ binary semiconductor composites were prepared by a simple ball milling method, and their phase, optical and electrochemical properties were analyzed. The experiment of visible-light photocatalytic removal of NO shows that with the gradual increase of WO₃ load, the material removal activity first increases and then decreases, which is mainly attributed to the separation efficiency of interfacial carriers improved by the appropriate phase composition and heterojunction. Moreover, the addition of WO₃ can effectively inhibit the formation of toxic intermediate, NO₂, and thus promote the formation of nitrate and nitrite. Through the active species capture test, it is found that both superoxide radical and hole play a major role in the photocatalytic reaction, and hydroxyl radical plays an auxiliary role. The analysis of energy band structure shows that the photocatalytic mechanism of the composites follows the type I process. Cyclic tests prove that the material has good reusability and structural stability.