Photocatalytic CO2 Reduction Over BiOX on Needle Coke–Derived Graphene Composites

Substantial research has been dedicated to advancing visible-light photocatalysts for the conversion of CO 2 into sustainable fuels. The overall efficiency of this process is critically dependent on both the effective generation/separation of photogenerated charge carriers and the adsorption/activation of CO 2 reactants. Bismuth oxyhalides (BiOX) are promising due to their layered structure and built-in electric field, which facilitate charge separation. However, their practical application is often limited by insufficient CO 2 adsorption capacity and restricted visible-light harvesting. Herein, we report a series of composite photocatalysts constructed via the in situ growth of BiOX on needle coke–derived graphene (NCG). This integrated structure leverages the high specific surface area and inherent heteroatom doping of NCG to enhance CO 2 adsorption, while the resulting intimate heterojunction significantly promotes visible-light absorption (especially within 500–800 nm) and accelerates interfacial charge transfer. The optimized BiOBr-25%NCG composite achieves a remarkable CO production rate of 46.32 μmol·g −1 ·h −1 from photocatalytic CO 2 reduction without any sacrificial agents, representing a 13-fold enhancement over pristine NCG and a ∼4000-fold increase compared to bare BiOBr. The superior performance is attributed to the synergistic enhancement of light absorption, charge separation kinetics, and CO 2 adsorption activation. This work presents a viable strategy for developing efficient, low-cost photocatalytic systems by integrating functional carbon matrices derived from industrial byproducts with semiconductor catalysts.