Although molecular oxygen activation plays a significant role in photocatalytic process for pollutants removal, it is still challenging to activate molecular oxygen into superoxide radical (O₂⁻) by photocatalysts under near-infrared (NIR) light irradiation. Herein, we successfully synthesized Ni²⁺-doped BiO_2-x nanosheets, which could efficiently achieve the molecular oxygen activation into O₂⁻ under ultraviolet (UV), visible and NIR irradiation. Meanwhile, we found the doping Ni²⁺ facilitated the formation of BiO_2-x nanosheets. More importantly, the contribution of doping Ni²⁺ on full spectrum molecular oxygen activation over Ni²⁺-doped BiO_2-x was further confirmed by experiments and density functional theory (DFT) study. The introduction of Ni²⁺ into BiO_2-x structure resulted in the formation of a new doping energy level band between the valence band (VB) and conduction band (CB) of Ni²⁺-doped BiO_2-x, which contributed to the faster separation of carriers and highly efficient full spectrum driven molecular oxygen activation under UV, visible and NIR irradiation, especially with the irradiation of NIR light as compared to BiO_2-x. In addition, the doping Ni²⁺ promoted the optical absorption property of BiO_2-x with narrowing band gap and the up-shift position of VB and CB. As expected, the Ni²⁺-doped BiO_2-x nanosheets exhibited enhanced photocatalytic activity for rhodamine B (RhB) degradation under UV, visible and NIR irradiation than pure BiO_2-x nanosheets. The photocatalyst still revealed high photocatalytic activity even after five cycles. Finally, a possible photocatalytic mechanism of the degradation processes by Ni²⁺-doped BiO_2-x was proposed. This work not only confirmed Ni²⁺ doping could promote the formation of BiO_2-x nanosheets and enhance their full spectrum driven molecular oxygen activation ability, but also presented an in-depth understanding on the mechanism of full spectrum driven molecular oxygen activation.

虽然分子氧活化在污染物去除光催化过程一个显著的作用，它仍然是具有挑战性的激活分子氧超氧自由基（ö ₂ ^- ）通过近红外（NIR）光照射下光催化剂。在此，我们成功地合成的Ni ²⁺掺杂BIO _2-X纳米片，这可能有效地实现分子氧活化为ö ₂ ^-下的紫外线（UV），可见光和NIR照射。同时，我们发现掺杂的Ni ²⁺促进了BiO _2-x纳米片的形成。更重要的是，掺杂Ni ²⁺的贡献实验和密度泛函理论（DFT）的研究进一步证实了分子光谱对氧原子在Ni ²⁺掺杂的BiO _2-x上的活化的影响。引进的Ni ²⁺为生物_2-X结构导致的价带（VB）和Ni的导带（CB）之间形成了新的掺杂能级带²⁺掺杂BIO _2-X ，这有助于与BiO _2-x相比，在UV，可见光和NIR辐照下，尤其是在NIR光辐照下，载流子的分离速度更快，并且高效的全光谱驱动分子氧活化。另外，掺杂Ni ²⁺通过窄带隙和VB和CB的上移位置，促进了BiO _2-x的光吸收性能。如所预期的，与纯BiO _2-x纳米片相比，Ni ²⁺掺杂的BiO _2-x纳米片在紫外，可见光和NIR照射下对罗丹明B（RhB）降解表现出增强的光催化活性。即使经过五个循环，光催化剂仍然显示出高的光催化活性。最后，提出了一种可能的光催化机理，即Ni ²⁺掺杂的BiO _2-x的降解过程。这项工作不仅证实了Ni ^2+的掺杂可以促进BiO _2-x的形成 纳米片并增强了其全光谱驱动的分子氧活化能力，但也对全光谱驱动的分子氧活化的机理提出了深入的认识。