In this paper, based on Bi₂O₃ and CoAl–layered double hydroxides (LDHs), a core–shell structure S–scheme heterojunction catalyst (Bi₂O₃@LDHs) was synthesized and used for photodegradation of Rhodamine B (RhB), a typical dye. The effects of the amount of catalyst (A), light intensity (B), pH value (C) and reaction temperature (T) on the degradation performance were discussed. The apparent kinetic equation of RhB photodegradation catalyzed by LDHs and Bi₂O₃@LDHs are: $ln(C/C_0)=-5.661\times {10}^5{e}^{-\frac{30.01\times {10}^3}{\mathit{RT}}}\times {[A]}_0^{0.9348}\times {[B]}_o^{1.0348}\times {[C]}_0^{0.9965}\times t$ and $ln(C/C_0)=-8.398\times {10}^3{e}^{-\frac{16.39\times {10}^3}{\mathit{RT}}}\times {[A]}_0^{1.2547}\times {[B]}_o^{1.5279}\times {[C]}_0^{1.0197}\times t$. Under the best reaction conditions of the amount of catalyst is 40 mg, the light intensity is 400 W, the reaction pH value is 9, and the reaction temperature is 303 K, the highest removal is 90.36%, and the activity is 37.65 mg g⁻¹h⁻¹. In addition, by means of radical characterization and DFT calculation, the formation mechanism of built–in electric field and the promotion of S–scheme electron transport path in heterojunction were systematically analyzed, and the degradation intermediates and degradation paths were also discussed.

在本文中，基于 Bi ₂ O ₃和 CoAl 层状双氢氧化物 (LDHs)，合成了一种核壳结构 S 型异质结催化剂 (Bi ₂ O ₃ @LDHs) 并用于光降解罗丹明 B (RhB) ，典型的染料。讨论了催化剂用量(A)、光照强度(B)、pH值(C)和反应温度(T)对降解性能的影响。LDHs和Bi ₂ O ₃ @LDHs催化RhB光降解的表观动力学方程为：$输入(C/C_0)=——5.661\times {10}^5{\mathrm{电子}}^{——\frac{30.01\times {10}^3}{\mathit{转播时间}}}\times {[\mathrm{一种}]}_0^{0.9348}\times {[乙]}_{○}^{1.0348}\times {[C]}_0^{0.9965}\times 吨$ 和 $输入(C/C_0)=——8.398\times {10}^3{\mathrm{电子}}^{——\frac{16.39\times {10}^3}{\mathit{转播时间}}}\times {[\mathrm{一种}]}_0^{1.2547}\times {[乙]}_{○}^{1.5279}\times {[C]}_0^{1.0197}\times 吨$. 在催化剂用量40mg、光强400W、反应pH值9、反应温度303K的最佳反应条件下，最高去除率为90.36%，活性为37.65mg/g ^-1小时^-1。此外，通过自由基表征和DFT计算，系统分析了内建电场的形成机制和异质结中S型电子传输路径的促进，并讨论了降解中间体和降解路径。