Modulating Photon Harvesting Through Constructing Oxygen Vacancies‐Rich 0D/2D Plasmonic Bi/Bismuth Oxybromide Upconversion Nanosheets Toward Improved Solar Photocatalysis

To harness solar energy comprehensively, developing photocatalysts with a broad spectrum response has received enormous attention. Herein, a full‐spectrum‐responsive Bi/BiOBr:Yb 3+ ,Er 3+ (BYE/Bi) heterostructure with oxygen vacancies (OVs) is designed and fabricated using the solvothermal method with subsequent heat treatment. The surface plasmon resonance (SPR) effect of Bi metal and OVs can not only extend the light absorption spectra but also promote the charge separation efficiency. The result of upconversion (UC) luminescence shows that the SPR absorption band of Bi nanoparticles overlaps with the excitation and emission bands of BiOBr:Yb 3+ ,Er 3+ nanosheets, which can induce a near‐infrared (NIR) plasmonic energy UC process and results in an enhanced green UC luminescence. The photocatalytic BPA degradation test shows that BYE/Bi‐2 shows the best photocatalytic activity, which is about 2.13‐fold, 1.41‐fold, and 2.73‐fold higher than that of BYE under UV−visible (vis)−near infrared (NIR), vis, and NIR light irradiations, respectively. Results reveal that the enhanced photocatalytic activity is ascribed to the Bi SPR effect and UC luminescence of BiOBr:Yb 3+ ,Er 3+ nanosheets, as well as the synergistic effects of OVs. This work not only provides ideas for the development of nonmetallic plasmon‐modified UC luminescent materials but also offers a pathway to develop high‐performance full‐spectrum photocatalysts for environmental applications.