Regulating CO and H₂ Ratios in Syngas Produced from Photocatalytic CO₂/H₂O Reduction by Cu and Co Dual Active Centers on Carbon Nitride Hollow Nanospheres

Forphotocatalytic CO2 reduction to produce syngas,there are challenges in achieving a high catalytic efficiency andprecise control over the product ratio. In this study, two non-noblemetal complexes Cobpy and Cubpy (bpy = 2,2 & PRIME;-bipyridine)as cocatalysts for CO2 reduction and hydrogen evolution,respectively, were in situ supported on carbon nitride hollow nanospheresto construct a hybrid system for photocatalytic syngas production.The resulting CO/H-2 ratio can be precisely regulated withina wide range of 0:1-9:1 by accurately controlling the contentof the two complexes. The presence of the two complexes promotes themigration of photogenerated electrons of the carbon nitride. CO2 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 methodis also applicable to other photocatalysts, such as CdS and TiO2 for generating syngas and regulating product ratios. Two non-noble metal complexes, Cobpy and Cubpy (bpy = 2,2 & PRIME;-bipyridine),employed as cocatalystsfor the CO2 reduction reaction and hydrogen evolution reaction,respectively, were in situ supported on carbon nitride hollow nanospheres(CNHS) to construct a hybrid system for photocatalytic syngas production.The resulting CO/H-2 ratio can be precisely regulated withina wide range of 0:1-9:1 by accurately controlling the contentof the two complexes.