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Hydrogen peroxide (H2O2) is an essential and versatile oxidant. The photocatalytic production of H2O2 is a promising alternative to the conventional anthraquinone oxidation process. In this work, BiOBr nanosheets with oxygen vacancies (OVs) were successfully synthesized by a solvothermal method in the presence of mannitol. The character of the nanosheets shortened the diffuse length of charge carriers, which is beneficial for the charge separation. The introduction of OVs enhanced the visible light absorption and also improved the carrier separation. Furthermore, OVs enhanced the activation of O2 molecules and facilitated the generation of ˙O2−. As a result, the products exhibited good performance in photocatalytic H2O2 production. After introducing HCOOH, the yield of H2O2 was further enhanced by a factor of 50, from 3 μmol h−1 to 150 μmol h−1. This work provides a reference to design high performance photocatalysts for H2O2 production through defect engineering. [ABSTRACT FROM AUTHOR]

Production of p-xylene (PX) via a broad biomass-derived furan cycloaddition has received incremental interest because of its renewable character. To date, the [4 + 2] cycloaddition reaction of furan derivatives with acrylic acid (AA) to synthesize PX has been achieved mainly by thermo-catalysis, but the stern reaction conditions usually lead to high energy costs. Herein, we report a copper-mediated decarboxylative cycloaddition within PW@HKUST-1 under visible-light irradiation to realize rapid synthesis of PX with 92.6% yield in 3 h under atmospheric pressure. Preliminary mechanistic studies reveal a radical decarboxylation process via ligand-to-metal charge transfer (LMCT) that initiates the [4 + 2] cycloaddition under visible-light irradiation. This work suggests that photoexcited [4 + 2] cycloaddition could be a cost-effective strategy for the synthesis of biomass-derived PX. [ABSTRACT FROM AUTHOR]

Carbon dioxide anion radical (CO 2 •- ) can act as a versatile single electron reductant, but its generation pathways are quite limited. Herein, we demonstrate that oxalic acid (OA) could be effectively and continuously utilized to produce CO 2 •- over Bi(C 2 O 4 )OH, a novel photocatalyst, under light irradiation. Bi(C 2 O 4 )OH would proceed with self-redox reactions under the light irradiation producing CO 2 •- , through the oxidation of C 2 O 4 2- . OA in the solution could recoordinate with Bi 3+ , thus maintaining the structure of the photocatalysts and the stability of the reactions. Benefiting from the fast reaction between CO 2 •- and O 2 in forming • O 2 - , hydrogen peroxide (H 2 O 2 ) would be efficiently produced (219.0 μmol/h). This study proposes a novel approach for harnessing OA containing wastewater and explores its potential application in the efficient production of H 2 O 2 .

Hydrogen peroxide (H 2 O 2 ) is an essential and versatile oxidant. The photocatalytic production of H 2 O 2 is a promising alternative to the conventional anthraquinone oxidation process. In this work, BiOBr nanosheets with oxygen vacancies (OVs) were successfully synthesized by a solvothermal method in the presence of mannitol. The character of the nanosheets shortened the diffuse length of charge carriers, which is beneficial for the charge separation. The introduction of OVs enhanced the visible light absorption and also improved the carrier separation. Furthermore, OVs enhanced the activation of O 2 molecules and facilitated the generation of ˙O 2 - . As a result, the products exhibited good performance in photocatalytic H 2 O 2 production. After introducing HCOOH, the yield of H 2 O 2 was further enhanced by a factor of 50, from 3 μmol h -1 to 150 μmol h -1 . This work provides a reference to design high performance photocatalysts for H 2 O 2 production through defect engineering.