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S-scheme heterojunctions have become an emerging type of effective photocatalysts to convert biomass. However, there are few reports on the synergistic S-type heterojunction and oxygen vacancy enhanced photocatalytic biomass conversion. Here, an AgInS 2 @CeO 2 -x S-scheme heterojunction photocatalyst with abundant oxygen vacancies was developed through a simple thermal and mild annealing process, allowing for the simultaneous production of xylonic acid and CO. Under visible light, the xylonic acid yield and CO evolution rate reached 60.0% and 3689.9 μmol g−1 h−1, respectively, through the decomposition of xylose. It was found that the S-scheme staggered band structure could improve sunlight utilization, increase the reduction power of photogenerated electrons, and enhance the separation and transfer of photogenerated charge carriers. Furthermore, oxygen vacancies on the surface of CeO 2 for AgInS 2 @CeO 2 -x heterojunction can suppress the recombination of generated electrons and holes. This study offers a promising approach for designing artificial photosynthetic systems to promote photocatalytic biomass conversion. [Display omitted] • The AgInS 2 @CeO 2 -x S-scheme heterojunctions with enhanced CeO 2 oxygen defects were designed. • The synergism between S-scheme heterojunctions and oxygen vacancies accelerated charge separation of AgInS 2 @CeO 2 -x. • The CO evolution and xylonic acid yield reached 3689.9 μmol g−1 h−1 and 60.0%. • The yields of xylonic acid and CO via AgInS 2 @CeO 2 -20 were 1.39 and 1.44 times greater than AgInS 2. [ABSTRACT FROM AUTHOR]

Copper oxide functionalized chitosan hybrid hydrogels for highly efficient photocatalytic-reforming of biomass-based monosaccharides to lactic acid. [Display omitted] • The CuO@CS-H had lower bandgaps, excellent stability, and alkalinity. • The photocatalyst can efficiently synthesize lactic acid in weak base system. • The photocatalyst has universality for synthesis of lactic acid from biomass-based monosaccharides. • Good yield of lactic acid was observed from two-thousand-fold scale-up experiment. Much attention has been focused on the photocatalytic-reforming of biomass to produce high-value chemicals due to their unique merits. In this study, we report a freezing-thawing strategy for the preparation of an alkaline CuO-chitosan hybrid hydrogel (CuO@CS-H). The synergism between CuO and alkaline chitosan hydrogel led to a highly efficient photocatalytic-reforming of xylose to lactic acid under a weak alkaline system, and the highest lactic acid yield is 81.6 %. The retained lactic acid yield was about 91.2 % after being used nine times. The reaction system is universal for the production of lactic acid from biomass-derived pentoses and hexoses, and O 2 − plays a major role in the synthesis of lactic acid. Industrial production of lactic acid via the as-proposed system was shown to be feasible according to a two-thousand-fold scale-up experiment. This work initiates a novel strategy of photocatalytic synthesis of lactic acid from biomass-based monosaccharides. [ABSTRACT FROM AUTHOR]