Regulating CO and H<sub>2</sub> Ratios in Syngas Produced from Photocatalytic CO<sub>2</sub>/H<sub>2</sub>O Reduction by Cu and Co Dual Active Centers on Carbon Nitride Hollow Nanospheres
Wei Zhang, Quan Gu, Xianliang Fu, Yanyan Wang, Yajun Jian, Huaming Sun, Ziwei Gao
Abstract
For photocatalytic CO 2 reduction to produce syngas, there are challenges in achieving a high catalytic efficiency and precise control over the product ratio. In this study, two non-noble metal complexes Cobpy and Cubpy (bpy = 2,2′-bipyridine) as cocatalysts for CO 2 reduction and hydrogen evolution, respectively, were in situ supported on carbon nitride hollow nanospheres to construct a hybrid system for photocatalytic syngas production. The resulting CO/H 2 ratio can be precisely regulated within a wide range of 0:1–9:1 by accurately controlling the content of the two complexes. The presence of the two complexes promotes the migration of photogenerated electrons of the carbon nitride. CO 2 can be reduced to CO on the photoreduced species Co(bpy) 2 + of Cobpy on CNHS, and H + can be reduced to H 2 on the photoreduced species Cu(bpy) 2 + of Cubpy . Furthermore, this method is also applicable to other photocatalysts, such as CdS and TiO 2 for generating syngas and regulating product ratios.