Au nanoparticle-controlled formation of metallic and oxidized Pt nanoparticles on graphitic carbon nitride nanosheets for H2 evolution. Issue 27 (18th June 2021) - Guo, Xin
Abstract : Metallic Pt electron-sink and Au LSPR effects, as well as the excellent co-catalyst capacity of Pt/Pt 2+, synergistically enhance the H2 evolution rate of g-C3 N4 with trace noble metal consumption. Abstract : Surface decoration of noble-metal cocatalysts on graphitic phase carbon nitride (g-C3 N4 ) with high efficiency and trace content for water splitting is exciting but difficult to achieve. Herein, we report the anchoring of Au and metallic/oxidized Pt nanoparticles (NPs) on g-C3 N4 as cocatalysts via a photoreduction process for enhancing photocatalytic H2 production. Au NPs are preferentially decorated on g-C3 N4, which can control the formation of metallic/oxidized Pt complex species. The well dispersed Au and metallic/oxidized Pt NPs improved the light-harvesting and the photo-generated carrier separation of g-C3 N4 . G-C3 N4 sequentially decorated with Au (0.3 wt%) and metallic/oxidized Pt (0.3 wt%) cocatalysts, exhibited the highest and stable H2 evolution rates of 2560 and 139 μmol h −1 g −1 under simulated sunlight and visible light ( λ ≥ 420 nm) irradiation, respectively, compared to the samples that are simultaneously and sequentially decorated with the same content of Pt and Au on g-C3 N4 . The enhanced photocatalytic activity is attributed to the synergistic effect of Au and metallic/oxidized Pt cocatalysts, i.e., the effective localized surface plasma resonance coupling between Pt and Au NPs, as well as electron-sink function of metallic Pt, which promote the generation and transfer of more carriers from g-C3 N4 to the Pt species, in addition to the superior hydrogen evolution capacity of metallic and oxidized Pt. This work maximizes the performance of noble-metal cocatalysts with minimized content and provides the possibility of realizing efficient solar-to-fuel conversion.