Hu Zhangli, Kuang Jiamin, Fu Wenmo, Hu Longxin, Lai Hua, Zhang Huanian, Liu Xing
College of Chemistry Materials, Hengyang Normal University Hengyang 421008 China
Hunan Provincial Key Laboratory of Functional Metal-Organic Compounds Hengyang 421008 China
RSC Adv. 2023 Jul 4;13(29):20031-20039. doi: 10.1039/d3ra02785f. eCollection 2023 Jun 29.
Brominated dyes, 2C- ( = 1-5), 3C-4 and 4C-4, were prepared through bromination of three carbazole-based D-π-A dyes, 2C, 3C and 4C with -bromosuccinimide (NBS). The detailed structures of the brominated dyes were confirmed by H NMR spectroscopy and mass spectrometry (MS). The introduction of the Br atom on the 1,8-positon of carbazole moieties led to blueshifted UV-vis and photoluminescence (PL) spectra, increased initial oxidation potentials and enlarged dihedral angles, indicating bromination enhanced non-planarity of the dye molecules. In the hydrogen production experiments, with the increase of the Br content in brominated dyes, the photocatalytic activity increased continuously (except 2C-1). The dye-sensitized Pt/TiO 2C-4@T, 3C-4@T and 4C-4@T, exhibited high hydrogen production efficiencies of 655.4, 877.9 and 905.6 μmol h g, respectively, which were 4-6-fold higher than those of 2C@T, 3C@T and 4C@T. The enhanced performance of photocatalytic hydrogen evolution was attributed to decreased dye aggregation resulting from the highly non-planar molecular structures of the brominated dyes.
通过用N-溴代琥珀酰亚胺（NBS）对三种咔唑基D-π-A染料2C、3C和4C进行溴化反应，制备了溴化染料2C-(=1-5)、3C-4和4C-4。通过1H NMR光谱和质谱（MS）确定了溴化染料的详细结构。在咔唑部分的1,8位引入Br原子导致紫外可见光谱和光致发光（PL）光谱发生蓝移，初始氧化电位增加，二面角增大，这表明溴化增强了染料分子的非平面性。在制氢实验中，随着溴化染料中Br含量的增加，光催化活性持续增加（2C-1除外）。染料敏化的Pt/TiO₂ 2C-4@T、3C-4@T和4C-4@T分别表现出655.4、877.9和905.6 μmol h⁻¹ g⁻¹的高制氢效率，分别比2C@T、3C@T和4C@T高4-6倍。光催化析氢性能的增强归因于溴化染料高度非平面分子结构导致的染料聚集减少。
