Jiang Zhixiang, Zhang Xiao, Chen Hsueh-Shih, Yang Ping, Jiang San Ping
School of Material Science & Engineering, University of Jinan, Jinan, 250022, P. R. China.
Fuels and Energy Technology Institute and Department of Chemical Engineering, Curtin University, Perth, WA6845, Australia.
Small. 2020 Oct;16(42):e2003910. doi: 10.1002/smll.202003910. Epub 2020 Sep 22.
Carbon nitride (g-C N ) nanostructure rebuilding is an effective means to modify its photocatalytic properties, especially the hollow micron-nanostructure. The increased scattering in the body effectively improves the light utilization efficiency and improves catalytic properties. In this work, fusiform-shaped g-C N capsules are created by controlling the nucleation kinetics of supramolecular assemblies. The fusiform-shaped capsule micron-nanostructure is synthesized with ultrathin wall thickness and adjusted carbon/nitride ratios which decrease the recombination rate of photo-generated carriers. The hollow nanostructure and relatively higher specific surface area of the fusiform-shaped capsule effectively enhance light scattering inside body and lead to an enhanced carrier utilization efficiency. Moreover, the decrease of bandgap and relatively negative conduction band position affect the response of hollow fusiform-shaped g-C N capsules (Hf-g-C N ) in visible light region and improve the photo-reducing performance. In term of H evolution property, Hf-g-C N has been improved to 7052 µmol g h , which is 10.9 times higher compared with bulk structure. More importantly, Hf-g-C N can produce CH at the rate of 1.63 µmol g h without help of co-catalyst and hole sacrificial agent in the photocatalytic reduction reaction of CO to CH . At same time, the selective photocatalytic reduction of CO is another advantage of Hf-g-C N .
氮化碳（g-C₃N₄）纳米结构重建是改变其光催化性能的有效手段，尤其是中空微米-纳米结构。体内散射的增加有效地提高了光利用效率并改善了催化性能。在这项工作中，通过控制超分子组装体的成核动力学来制备纺锤形g-C₃N₄胶囊。合成了具有超薄壁厚和可调节碳/氮比的纺锤形胶囊微米-纳米结构，这降低了光生载流子的复合率。纺锤形胶囊的中空纳米结构和相对较高的比表面积有效地增强了体内的光散射，并提高了载流子利用效率。此外，带隙的减小和相对负的导带位置影响中空纺锤形g-C₃N₄胶囊（Hf-g-C₃N₄）在可见光区域的响应，并提高了光还原性能。就析氢性能而言，Hf-g-C₃N₄已提高到7052 μmol g⁻¹ h⁻¹，与块状结构相比高出10.9倍。更重要的是，在CO₂光催化还原为CH₄的反应中，Hf-g-C₃N₄在没有助催化剂和空穴牺牲剂的情况下，能够以1.63 μmol g⁻¹ h⁻¹的速率产生CH₄。同时，CO₂的选择性光催化还原是Hf-g-C₃N₄的另一个优势。
