Ren Hai-Tao, Cai Chao-Chen, Zhu Peng-Yue, Wang Cong, Wu Song-Hai, Liu Yong, Han Xu
Tianjin and Ministry of Education Key Laboratory of Advanced Textile Composite Materials, School of Textile Science and Engineering, Tiangong University, Tianjin 300387, P.R. China.
School of Environmental Science and Engineering, Tianjin University, Tianjin 300072, P.R. China.
Langmuir. 2024 Apr 9;40(14):7384-7394. doi: 10.1021/acs.langmuir.3c03651. Epub 2024 Mar 26.
Photocatalytic technology is a popular research area for converting solar energy into environmentally friendly chemicals and is considered the greenest approach for producing HO. However, the corresponding reactive oxygen species (ROS) and pathway involved in the photocatalytic generation of HO by the BiWO-glucose system are still not clear. Quenching experiments have established that neither OH nor h contribute to the formation of HO, and show that the formed surface superoxo (≡Bi-OO) and peroxo (≡Bi-OOH) species are the predominant ROS in HO generation. In addition, various characterizations indicate the enhanced electron-transfer on the surface of BiWO with increasing contents of glucose via the ligand-to-metal charge transfer pathway, confirming H-transfer from glucose to ≡Bi-OO or ≡Bi-OOH. The increased production of HO with decreasing bond dissociation energy (BDE) values of various phenolic compounds again supports the H-transfer mechanism from phenolic compounds to ≡Bi-OO and then to ≡Bi-OOH. DFT calculations further reveal that on the BiWO surface, oxygen is sequentially reduced to ≡Bi-OO and ≡Bi-OOH, while H-transfer from HO or glucose to ≡Bi-OO and ≡Bi-OOH, resulting in the production of HO. The lower energy barrier of H-transfer from adsorbed glucose (0.636 eV) than that from HO (1.157 eV) indicates that H-transfer is more favorable from adsorbed glucose. This work gives new insight into the photocatalytic generation of HO by BiWO in the presence of glucose/phenolic compounds via the H-abstraction pathway.
光催化技术是将太阳能转化为环境友好型化学品的热门研究领域，被认为是生产羟基自由基（HO）最绿色的方法。然而，BiWO-葡萄糖体系光催化生成HO所涉及的相应活性氧物种（ROS）和途径仍不明确。猝灭实验表明，羟基自由基（OH）和空穴（h）均不参与HO的形成，并表明所形成的表面超氧物种（≡Bi-OO）和过氧物种（≡Bi-OOH）是HO生成过程中的主要ROS。此外，各种表征表明，随着葡萄糖含量的增加，通过配体-金属电荷转移途径，BiWO表面的电子转移增强，证实了氢从葡萄糖转移至≡Bi-OO或≡Bi-OOH。随着各种酚类化合物的键解离能（BDE）值降低，HO的产量增加，这再次支持了从酚类化合物到≡Bi-OO再到≡Bi-OOH的氢转移机制。密度泛函理论（DFT）计算进一步揭示，在BiWO表面，氧依次还原为≡Bi-OO和≡Bi-OOH，而氢从HO或葡萄糖转移至≡Bi-OO和≡Bi-OOH，从而产生HO。从吸附的葡萄糖进行氢转移的能垒（0.636 eV）低于从HO进行氢转移的能垒（1.157 eV），这表明从吸附的葡萄糖进行氢转移更有利。这项工作通过氢提取途径，为在葡萄糖/酚类化合物存在下BiWO光催化生成HO提供了新的见解。
