Constructing heterojunctions would result in the change of valence band position, which is an important factor determining the oxidative ability of photo-induced holes, has received scant attention. In this paper, β-Bi₂O₃/Bi₂O₂CO₃ composites with different ratios were obtained via ionic-liquid-assisted solvothermal and in-situ calcination processes. UV–vis DRS, Mott-Schottky test, and Kelvin probe measurement showed the change of band gaps of β-Bi₂O₃ and Bi₂O₂CO₃ before and after heterojunction formation. SPV, ESR, photocurrent, and scavenger experiments identified the separation efficiency of photo-generated electrons and holes, as well as the active species generated in the photocatalytic process. The photocatalytic mechanism was investigated by the degradation of Rhodamine B (RhB) upon visible-light and simulated sunlight, respectively. The results demonstrated that β-Bi₂O₃/Bi₂O₂CO₃ heterojunctions possessed enhanced separation efficiency and higher degradation ability than the individuals under visible-light irradiation due to effective electron transfer. However, lower performance under simulated sunlight was observed, although their separation efficiency remained high. The decisive reason for this was that the up-shift of valence band of Bi₂O₂CO₃ induced by hybridization and the transition of holes from VB of Bi₂O₂CO₃ to that of β-Bi₂O₃ with more negative potential decreased the oxidative ability of holes, which surpassed the positive influence of enhanced separation efficiency.

构造异质结会导致价带位置的变化，这是决定光诱导空穴氧化能力的重要因素，受到关注的很少。在本文中，β-Bi系₂ ö ₃ /铋₂ ö ₂ CO ₃复合物具有不同的比率通过离子液体辅助溶剂热和得到的原位煅烧过程。的UV-vis DRS，莫特肖特基测试，和开尔文探针测量显示的带隙的变化β-Bi系₂ ö ₃和Bi ₂ ö ₂ CO ₃异质结形成之前和之后。SPV，ESR，光电流和清除剂实验确定了光生电子和空穴的分离效率，以及在光催化过程中产生的活性物质。通过在可见光和模拟阳光下降解若丹明B（RhB）分别研究了光催化机理。结果表明，β-Bi系₂ ö ₃ /铋₂ ö ₂ CO ₃由于有效的电子转移，异质结比可见光照射下的个体具有更高的分离效率和更高的降解能力。然而，尽管它们的分离效率仍然很高，但是在模拟阳光下观察到了较低的性能。造成这种情况的决定性原因是，铋的价电子带的升档₂ ö ₂ CO ₃通过杂交诱导和空穴从毕的VB过渡₂ ö ₂ CO ₃到的β-Bi系₂ ö ₃与多个负电位降低了空穴的氧化能力，超过了提高分离效率的积极影响。