Simulated design of Cu₂N/BiOCl for selective synthesis of C₂ alcohol products in photocatalytic reduction of CO₂ via nitrogen vacancy on modified square copper sites

The increasing atmospheric CO₂ concentration resulting from fossil fuel combustion has exacerbated global warming. It is imperative to mitigate CO₂ emissions and convert them into valuable chemicals through innovative solutions. Herein, we employ density functional theory (DFT) calculations to design a defective Cu₂N/BiOCl heterostructure incorporating nitrogen vacancies (Nv) for selective photocatalytic CO₂ reduction to C₂ alcohols. The formation of an ohmic contact in this heterostructure significantly facilitates the transfer of photo-generated electrons. Through the introduction of nitrogen vacancies on Cu₂N/BiOCl, two key roles are realized. The first is enhanced reactivity of the square-symmetric copper sites, which promote CO₂ activation and C–C coupling through improved electron density and orbital interactions. The second is the creation of an intensified interfacial electric field at the BiOCl-Cu₂N interface, effectively promoting charge separation while suppressing carrier recombination. This synergistic effect remarkably boosts photocatalytic efficiency and product selectivity toward the production of high-value two-carbon alcohols. This work provides critical insights into the rational design of photocatalysts for CO₂ reduction, addressing key challenges in sustainability and energy applications.