Visible Light CO₂ Reduction to CH₄ Using Hierarchical Yolk@shell TiO_2–xH_x Modified with Plasmonic Au–Pd Nanoparticles

Engineering of advanced semiconductor photocatalysts for CO₂ conversion to solar fuels is a promising strategy to solve the greenhouse effect and energy crisis. Herein, hierarchical urchin-like yolk@shell TiO_2–xH_x decorated with core/shell Au–Pd plasmonic nanoparticles (HUY@S-TOH/AuPd) have been prepared using a multistep process and are employed as an advanced visible light active photocatalyst in CO₂ conversion to CH₄ with a rate of 47 μmol/g_cat·h (up to 126 μmol/g_cat after 7 h). Different engineered sites in this structure for high gas adsorption, powerful visible light activation, and intense electron transportation are responsible for the observed high photocatalytic CO₂ conversion efficiency. The present smart design process can produce considerable cooperation in not only disclosing the architectural engineering for the improvement of photoconversion efficiency but also disclosing it as a viable and appropriate photocatalytic process to sustainable energy production.