Advancing CO₂ to CH₄ conversion: The pivotal role of RuCu alloy in crystalline red phosphorus photocatalysis

Crystalline red phosphorus (CRP), a newly emerging photocatalyst, shows promise for selective CH₄ production from CO₂ and H₂O. Yet, its potential remains largely untapped, particularly in enhancing photocatalytic performance. We address this gap by incorporating RuCu alloy nanoparticles into CRP, significantly boosting its efficiency in converting CO₂ to CH₄. Advanced analyses demonstrate that the synergistic mechanism between the RuCu alloy and CRP facilitates improved charge separation and expands the availability of active sites, leading to an impressive CH₄ yield of 19.7 μmol g⁻¹ h⁻¹. Importantly, the inclusion of Cu in the alloy modifies the catalytic reaction pathways facilitated by Ru, achieving an exceptional CO₂ to CH₄ selectivity of 96 %. This performance surpasses that of many existing elemental-based and Ru-containing photocatalysts. Our research highlights the potential of functionalized elemental photocatalysts and the importance of alloy composition in photocatalyst design for sustainable CO₂ conversion. © 2024 Elsevier B.V.