Henan Key Laboratory of Coal Green Conversion, College of Chemistry and Chemical Engineering, Henan Polytechnic University, Jiaozuo 454003, China.
Collaborative Innovation Center of Coal Work Safety of Henan Province, Jiaozuo 454003, China.
Phys Chem Chem Phys. 2023 Jun 7;25(22):15219-15236. doi: 10.1039/d3cp00774j.
Herein, a novel type-II BiVO/BiOI (BVOI) heterojunction electrode material was successfully fabricated by using a facile two-step electrodeposition approach. The experimental results revealed that BiOI nanosheets were deposited onto the surface of BiVO particles successfully, with the special morphology providing more active sites, which was beneficial to the improvement of PEC performance. According to the electrochemical performance tests, it could be observed that the construction of a heterojunction effectively promoted the separation of photoinduced electron-hole pairs and increased the transfer rate of surface charges. Under visible-light irradiation, the BVOI-300 photoanode possessed the highest PEC β-naphthol degradation rate at pH = 7, which approximately reached 82%, whose corresponding kinetic constant was 1.4 and 1.5 times higher than those of pure BiVO and BiOI. After five cycles, the degradation rate still remained at 64.61%. The band structure of the BVOI electrode was deduced, and the PEC mechanism of the BVOI electrode was investigated through the radical trapping quenching experiments and ESR test, which indicated that the ˙OH, h and ˙O radicals were crucial active species in the PEC β-naphthol degradation process. For the BVOI-300 working electrode, the TOC content of coal gasification wastewater (CGW) decreased from 94.44 to 54.4 mg L, and the removal rate reached 42.4%. GC-MS was used to identify the organic components of coal gasification wastewater, which was expected to provide reference for remedying actual gasification wastewater containing refractory organic pollutants and offer a new development direction for the treatment of actual coal chemical wastewater.
本文采用简便的两步电沉积法成功制备了新型 II 型 BiVO/BiOI（BVOI）异质结电极材料。实验结果表明，BiOI 纳米片成功沉积在 BiVO 颗粒表面，特殊的形貌提供了更多的活性位点，有利于提高光电化学性能。根据电化学性能测试，可观察到异质结的构建有效地促进了光生载流子的分离，并提高了表面电荷的转移速率。在可见光照射下，pH = 7 时，BVOI-300 光阳极具有最高的 PEC β-萘酚降解率，约为 82%，其相应的动力学常数分别比纯 BiVO 和 BiOI 高 1.4 和 1.5 倍。经过五次循环后，降解率仍保持在 64.61%。推断了 BVOI 电极的能带结构，并通过自由基捕获猝灭实验和 ESR 测试研究了 BVOI 电极的光电化学机理，表明˙OH、h 和˙O 自由基是 PEC β-萘酚降解过程中的关键活性物质。对于 BVOI-300 工作电极，煤气化废水（CGW）的TOC 含量从 94.44 降至 54.4 mg L，去除率达到 42.4%。GC-MS 用于鉴定煤气化废水中的有机成分，有望为修复含有难降解有机污染物的实际气化废水提供参考，并为实际煤化工废水的处理提供新的发展方向。
