He Yujie, Zhang Haipeng, Wang Zeyan, Zheng Zhaoke, Wang Peng, Liu Yuanyuan, Cheng Hefeng, Zhang Xiaoyang, Da Ying, Huang Baibiao
State Key Laboratory of Crystal Materials, Shandong University, Jinan 250100, People's Republic of China.
School of Physics, Shandong University, Jinan 250100, People's Republic of China.
ACS Omega. 2022 Apr 7;7(15):12816-12824. doi: 10.1021/acsomega.2c00048. eCollection 2022 Apr 19.
Imines are important multifunctional intermediates for the synthesis of pesticides, pharmaceuticals, biologics, and fine chemicals. The direct photoelectrochemical (PEC) oxidation of amines to imines is a highly selective, efficient, green, and gentle method. Interestingly, the constructive merging of the PEC oxidation of amines with the production of hydrogen can accelerate hydrogen evolution due to the less challenging oxidation of amines such as benzylamine (BN) in comparison to sluggish water oxidation. Herein, Mo-doped BiVO photoanodes were prepared and first applied to simultaneously oxide benzylamine (BN) to -benzylidenebenzylamine (BI) and produce hydrogen in a closed two-chamber, three-electrode PEC cell After illumination at a bias of 1.3 V vs SCE for 3 h, the 3% Mo-doped BiVO photoanode achieved a maximum yield of ∼94 μmol h at a 1 × 1 cm area with a BN to BI selectivity of almost 100% and a Faradaic efficiency of 98.4%. Our electrode presented enhanced photocorrosion resistance in acetonitrile solvent. Additionally, the PEC oxidations of benzylamine derivatives with different substituents (-F, -Cl, -Br, -CH, -OCH) to the corresponding imines were also investigated. The results indicated that the Mo-doped BiVO photoanode exhibited an excellent performance in the oxidation of these benzylamine derivatives with corresponding amine to imine selectivities of almost 100% and Faradaic efficiencies of >95%.
亚胺是合成农药、药物、生物制品和精细化学品的重要多功能中间体。胺直接光电化学（PEC）氧化为亚胺是一种高度选择性、高效、绿色且温和的方法。有趣的是，由于与缓慢的水氧化相比，苄胺（BN）等胺的氧化难度较小，将胺的PEC氧化与氢气生产建设性地结合可以加速析氢。在此，制备了Mo掺杂的BiVO光阳极，并首次将其应用于在封闭的双室三电极PEC电池中同时将苄胺（BN）氧化为亚苄基苄胺（BI）并产生氢气。在相对于饱和甘汞电极（SCE）为1.3 V的偏压下光照3小时后，3%Mo掺杂的BiVO光阳极在1×1 cm的面积上实现了约94 μmol h的最大产率，BN到BI的选择性几乎为100%，法拉第效率为98.4%。我们的电极在乙腈溶剂中表现出增强的抗光腐蚀性能。此外，还研究了具有不同取代基（-F、-Cl、-Br、-CH、-OCH）的苄胺衍生物氧化为相应亚胺的PEC过程。结果表明，Mo掺杂的BiVO光阳极在氧化这些苄胺衍生物方面表现出优异的性能，相应的胺到亚胺的选择性几乎为100%，法拉第效率>95%。
