One-pot synthesis of porous Ag@Pt core–shell cocatalysts on g-C3N4 for enhanced photocatalytic H2 production from lignocellulose reforming†

Abstract

Pt-promoted g-C₃N₄ is a well-established photocatalyst for H₂ evolution; however, it demonstrates limited efficiency when utilizing low-cost lignocellulose waste from natural sources as the sacrificial reagent. To address this limitation, we developed porous Ag@Pt core–shell cocatalysts on g-C₃N₄ through a single-step process that combines deposition–precipitation, photo-reduction and galvanic replacement in an alkaline solution. Our experiments demonstrated a significant synergistic effect between Ag and Pt: the bimetallic cocatalyst with an Ag/Pt weight ratio of 1 : 3 achieved a H₂ evolution rate of 652.7 μmol g⁻¹ h⁻¹, outperforming Pt alone by 4.7 times and Ag alone by 41.6 times. This enhancement is attributed to more efficient photoelectron trapping, optimal H* adsorption strength, and increased exposure of Pt active sites within the porous core–shell structure. Importantly, our catalysts can be directly applied to various lignocellulosic biomass wastes without any pretreatment. This study highlights the potential of bimetallic synergy to boost hydrogen production and reduce costs associated with noble metals.