The BiOBr:Yb³⁺,Er³⁺/g-C₃N₄ (BYE/CN) p-n junction photocatalysts were successfully fabricated by a stepwise method. Experimental results show that Er³⁺/Yb³⁺ were successfully doped into BiOBr lattice. As-obtained BYE/CN exhibited strong NIR light absorption and upconversion emission from NIR to UV–visible due to the upconversion transition of Er³⁺. The p-n junction was constructed due to the appropriate alignment band structure of BYE and g-C₃N₄, which distinctly suppresses the recombination rate of electron-hole pairs. Compared with pure BYE and CN, as-synthesized BYE/CN samples exhibit distinctly improved photoactivities under the irradiation of visible or NIR light, which can be attributed to the upconversion effect of Er³⁺ and the construction of p-n junction. This result may provides a promising system for efficient harvest of the NIR light, which will contribute to the utilization of solar energy in the future.

采用分步法成功制备了BiOBr：Yb ³⁺，Er ³⁺ / gC ₃ N ₄（BYE / CN）pn结光催化剂。实验结果表明，Er ³⁺ / Yb ³⁺被成功掺杂到BiOBr晶格中。由于Er ³⁺的上转换，所获得的BYE / CN表现出较强的NIR光吸收和从NIR到UV可见的上转换发射。由于BYE和gC ₃ N ₄具有适当的取向带结构，因此构建了pn结，这明显抑制了电子-空穴对的复合率。与纯BYE和CN相比，合成后的BYE / CN样品在可见光或NIR光的照射下显示出明显改善的光活性，这可以归因于Er ³⁺的上转换效应和pn结的构建。这一结果可能为有效收集NIR光提供一个有前途的系统，这将为将来的太阳能利用做出贡献。