Novel mesoporous Pt@n-AgI/n--MoO3 ternary nanocomposite for enhanced hydrogen production from glycerol under visible illumination

A novel mesoporous n-AgI/n-alpha-MoO3 nanocomposites with large surface area were constructed by hydrothermal approach utilizing hexamethylenetetramine (HMT) as an organic building block (cage-like). Pt nanoparticles (NPs) were highly distributed over AgI/alpha-MoO3 nanocomposites in situ during the photocatalysis reaction for photocatalytic H-2 evolution under visible exposure. The H-2 evolution results indicated that 9%AgI/alpha-MoO3 nanocomposite exhibited the best H-2 evolution ability, and the total H-2 amount was determined at about 24100 mu molg(-1) within 9 h illumination using 1 g/L the photocatalyst dosage, which increased to 28920 mu molg(-1) at 2.5 g/L. The H-2 amount of AgI/alpha-MoO3 photocatalyst was fostered similar to 40 and 10 times larger than that of alpha-MoO3 and AgI NPs. The optimal 9%AgI/alpha-MoO3 (2521.8 mu molg(-1)h(-1)) presented 34.4 and 8.61 times higher H-2 evolution rate compared to alpha-MoO3 (73.23 mu molg(-1)h(-1)) AgI (292.91 mu molg(-1)h(-1)). The resultant S-scheme AgI/alpha-MoO3 heterojunctions enhanced the separation efficiency of photocarriers with a remarkable enhancement of H-2 evolution. The n-n heterojunction AgI/alpha-MoO3 nanocomposite inhibited the recombination of electrons and holes, decreased photoluminescence intensity, enhanced the current density, and promoted photocatalytic ability. The obtained AgI/alpha-MoO3 nanocomposite can maintain stability for 45 h of illumination continuously in the photocatalysis reactions for five consecutive cycles. These results provide a simple approach to designing S-scheme photocatalysts with a high separation rate of carriers to promote solar energy conversion efficiency.