Efficient photocatalytic reforming of cellulose for H2 production enabled by oxygen-vacancy rich SrMoO4/palygorskite nanocomposite

Abstract

Photocatalytic reforming of biomass into hydrogen along with the simultaneous production of high-value chemicals, plays a significant role in advancing a sustainable economy. A major challenge in this process is the effective utilization of photogenerated holes while simultaneously preventing the rapid recombination of photoinduced carriers, which is crucial for optimizing solar-to-hydrogen conversion efficiency. In this study, an exquisite oxygen-rich vacancy (OV) plasmonic SrMoO4/phosphor acidized palygorskite (H-Pal) nanocomposite was prepared for efficient photocatalytic H2 evolution while producing high value-added lactic acid (LA) simultaneously. Results showed that the integration of local surface plasmon resonance (LSPR) effect and OV enhanced the photothermal catalytic conversion of cellulose reaching as high as 87%. Notably, the selectivity of LA reached as high as 31% while the H2-evolution efficiency reached 906 μmol•g-1•h-1. The local thermal effect improved the conversion efficiency of cellulose, and the OV in SrMoO4 introduced instantaneous Lewis acid sites during light irradiation, which improved the selectivity for LA. Moreover, the formation of an S-scheme SrMoO4-OV/H-Pal heterostructure effectively inhibited the recombination of photogenerated electron-hole pairs and maintained a high redox potential. This work demonstrates a promising strategy for efficient photocatalytic H2-evolution, coupled with production of high-valuable chemicals from biomass resources by taking advantage of clay materials.