CO₂ -Mediated Photocatalytic Chlorine Production Over Bismuth Oxychloride in Chloride Solution

As one of the most commonly bulky chemicals, chlorine is conventionally manufactured by electrolysis of NaCl solution in the chlor-alkali process, which requires a huge supply of electrical energy. The photocatalytic route to produce chlorine by using solar energy and NaCl solution offers a promising strategy to reduce energy consumption and bring economic benefits. Herein, it was found that the introduction of CO₂ would enhance the productivity of Cl₂ from 8.24 μmol⋅h^-1 to 39.6 μmol⋅h^-1 in NaCl solution over BiOCl. Experimental studies reveal that the CO₂ species (CO₃ ^2- ) entered into the crystal texture of BiOCl and the interlayer space between [Bi₂ O₂ ]²⁺ slabs were increased and distorted, accelerating the cycle of Cl species. Besides, the cycle of carbonate species also existed and accelerated the reaction efficiency of Cl^- oxidation to Cl₂ . This work provides a new feasible method of using abundant CO₂ resources to accelerate the process of chlorine production via photocatalysis.