Metal oxides have attracted an increasing attention for the photo-degradation of organic containments. Deep understanding of the physical parameters correlated with the photocatalytic process is critical and beneficial for finding an efficient and robust photocatalyst. Herein, by taking SnO₂ as a prototypical model, we systematically study exciton energy, effective mass, carrier mobility and partial charge density based on the density functional theory (DFT). We demonstrate that the obtained exciton energy is quite low and can be effectively dissociated into charge carriers at room temperature. The estimated carrier mobility of electrons is about 50 times greater than that of holes. More interestingly, analyzing partial charge density on the top of the valence band reveals that the photocatalytic oxidation reaction site would occur on the O-p state. Experimentally, SnO₂ nanoparticles have been synthesized by a simple method and characterized by Powder XRD and TEM. With the photocatalyst SnO₂, more than 90% methyl blue (MB) and Rhodamine B (RhB) are degraded under the UV light irradiation within 50 min and 270 min, respectively. Trapping experiments reveal that ˙OH are the main active species to oxidize the organic dye and mainly originate through the oxidation of holes (h⁺). This study establishes an in-depth understanding of electronic structure and photocatalysis and provides insights into the designing of new photocatalytic materials.

中文翻译：

---

SnO ₂纳米颗粒光催化剂的快速制备：对有机染料的计算理解和光催化降解†

金属氧化物已经引起了对有机容器光降解的越来越多的关注。对与光催化过程相关的物理参数的深刻理解是至关重要的，对于寻找有效而坚固的光催化剂是有益的。在这里，通过服用SnO ₂作为原型模型，我们基于密度泛函理论（DFT）系统地研究了激子能量，有效质量，载流子迁移率和部分电荷密度。我们证明，所获得的激子能量非常低，并且可以在室温下有效地离解为电荷载流子。电子的估计载流子迁移率大约是空穴的载流子迁移率的50倍。更有趣的是，分析价带顶部的部分电荷密度表明，光催化氧化反应位点将发生在Op态上。实验上，已经通过一种简单的方法合成了SnO ₂纳米颗粒，并通过粉末XRD和TEM对其进行了表征。与光催化剂SnO ₂分别在50分钟和270分钟的紫外线照射下降解了90％以上的甲基蓝（MB）和若丹明B（RhB）。诱捕实验表明，˙OH是氧化有机染料的主要活性物质，主要来自空穴（h ⁺）的氧化。这项研究建立了对电子结构和光催化作用的深入理解，并为新型光催化材料的设计提供了见识。